Table of contents

Preface

The 3rd International Conference on New Energy and Future Energy System (NEFES 2018) was held from August 21st to 24th, 2018 in Shanghai, China. The technical program comprised two keynote speakers, forty invited speakers, six oral presentation sessions and an interesting poster session.

NEFES 2018 is dedicated to facilitating the global development of new energy and exploring ways in which the latest research results can be shared. This volume records the proceedings of NEFES 2018 and contains 116 rigorously selected manuscripts submitted to the NEFES 2018 conference. All the manuscripts were selected depending on their quality and relevance to the conference.

The Organizing Committee would like to thank all the authors who contributed to NEFES 2018 and also the reviewers who provided their valuable comments and suggestions.

Editor

Dr. Grigorios L. Kyriakopoulos

National Technical University of Athens, Greece.

All papers published in this volume of IOP Conference Series: Earth and Environmental Science have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

With the integration of large-scale wind power plants (WPPs), there is more and more demand for peak regulation service, and the peak regulation cost is increasing too. Reasonable calculation of peak regulation service cost caused by wind power generation (WPG) is the premise of stimulating conventional units to provide peak regulation services. After introducing the concept of peak regulation service in China, the impact of WPG on peak regulation is analyzed, and a quantitative model of peak regulation cost caused by WPG is put forward form the view point of the value of unit output adjustment. An optimization model with paid peak regulation is established to analyze the impact of WPG on peak regulation costs. The proposed method is tested on a 10-thermal power units system with WPPs, and the results verify the effectiveness of the proposed method.

On the basis of BP-GA algorithm for boiler efficiency and NOx emission concentration, a combustion simulation model was established. By learning the training samples based on low NOx combustion adjustment tests, the combustion simulation model can accurately map the nonlinear relationship between boiler operation parameters and boiler efficiency and NOx emission concentration. Genetic algorithm was used to obtain the optimization strategies to get the best boiler efficiency and NOx emission concentration, which provides guidance for the operation.

Circular economy system of energy and heavy chemical industry park is usually assessed by efficiency, economy and environmental impact indicators. Few studies have focused on the integrity and comprehensiveness of system operation. Based on energy value theory, we develop four indices, namely, energy yield ratio, environmental loading ratio, energy index of sustainable development and energy conversion ratio. These indices are then applied to comprehensively evaluate circular economy systems with different media and capacity. An empirical analysis is conducted to the circular economy system of Energy and Heavy Chemical Industry Park in Jinjie of Yulin City at different development phases (initial phase, 1st phase and 2nd phase). The results show that as the system is being constantly improved and updated, the overall performance increases, and the capacity of the system for sustainable development increases dramatically. In the meantime, the energy investment ratio has been rising, though the environmental loading ratio is relatively high. It is necessary to increase the ecological efficiency of the system by expanding and enriching the ecological chain of the system.

This paper presents five different designs of single slope solar water stills. These still designs would probably be useful in small homes wishing to purify water for their daily drinking needs. Models of the stills ranging between 1 m² and 1.5 m² glazing area are manufactured and tested in real outdoor conditions. Two of the stills are double glazed and have external condensers, with one of them using forced steam extraction. A third still is mounted on a sun tracking pillar. The remaining two are simple collapsible and portable units but of different slopes. A method of evaluating the designs is illustrated. It relies on a focus on the purpose of a solar still and what scarce resources are required to get outputs from it. Thus, the stills are evaluated based on function, quality, productivity and cost. It is found that the tracking unit out performs the others on function and quality criteria but it is outcompeted on efficiencies and cost criteria. Condensate drip-back was found to be an issue that necessitates use of slopes that do not necessarily yield maximum energy incidence on the stills. It was also found that double glazing and external condensation did not help improve performance on any of the criteria. It is concluded and recommended that an ideal single slope solar water purifier operating in weather similar to Cape Town's summer season, would need to have a thin single glazing, sloped towards 45°, portable and sun tracking.

Traditional medium frequency induction furnace usually adopts analog circuit, which use the theory of PLL to synchronize the drive signal with the induced current signal, so that the upper and lower devices of each phase leg could be gated simultaneously Besides, some problems appear subsequently such as matching debugging difficulty and high failure rate. This paper describes the effect of the burden on the resonant electromagnetic field and resonant frequency through theoretical analysis and magnet field simulation. Based on this, a control and monitoring system designed by digital passive trigger architecture is proposed, phase locking of which is performed according to the frequency of the system itself, fully ensuring that the thyristor will not be simultaneous. In order to improve the stability of the system, this paper optimizes the inverter output control process. At the same time, a friendly human-computer interaction platform is designed, which can achieve distributed data mining, and improve the quality of the product and find the common problems in the product. Finally, the reliability of the control system is verified by experiments.

Due to a series of environmental pollution and energy crisis, much attention is focused on developing clean renewable energy. Many institutes in different nations have interesting in studying the usage of solar heaters into buildings. In China, solar energy heat usage technology in buildings has a big potential market and has been rapidly developed. So, in this paper, a solar thermal system in building used for space heating and domestic hot water production has been studied. A simulation calculation method is put forward by Polysun for finding the optimal size of three main components for the solar thermal system, including the tilt angle of collectors, volume of the buffer and area of the collectors. Moreover, the relative impact of those three parameters on the optimizing indexes (SF, E_tot and f) is investigated where all indexes are most affected by the area of the collectors while the tilt angle of collectors and the volume of buffer both present a relatively small influence.

A photovoltaic generation system is affected by many factors. The traditional method of forecasting photovoltaic power generation is more complicated. A double-level neural network is designed with consideration of these factors: the first level network calculates a real solar radiation with input of theory radiation and weather coefficient; the second level network calculates the final result generation power with input of real solar radiation which comes from the first network and the highest temperature which comes from weather forecast. The final power results indicate this method has good forecast capacity, calculate results are very close to measure value and errors are less than single level network.

The impact and significance of renewable energy in developing countries is increasing rapidly in latest years. There is much need of energy dependence to be based on off grid photovoltaic systems in developing countries like Pakistan which are suffering from severe power shortfalls annually and load shedding concern. In this paper, a concept assessment and estimation of standalone photovoltaic system is done for the site of Quetta, Pakistan in comparison to the location of the Copiapo-Chamonate. Copiapo-Chamonate site is situated in Atacama Desert which is often labelled as the best solar irradiation receiving location in the world with maximum solar insolation reaching to 9.28 kWh/m²/day. The systems for both locations is modelled and simulated in PVSYST for a constant load of 11.9 kWh/day with seasonal tilt adjustment. According to the simulation, results of the parameters including performance ratio, solar fraction, energy supplied to the load etc. show that Quetta meet its individual household demand quite efficiently.

In this study a highly efficient compressed air driven hydraulic motor system is designed, developed and tested. The basic concept of using a hydraulic motor to transform the energy of compressed air (which compressing the hydraulic oil) to mechanical energy is developed, which can use the energy in compressed air more efficiently than the traditional piston type air engine. However, due to the air pressure exhale from the converter still has some energy. To recover the energy, a booster is used to recover the energy. In this study, both theoretical model and experiment device of the system are developed; several experiments to validate the theoretical model are made. It was found that the efficiency of the system is good when using the booster.

The PWR (pressurized water reactor) vessel contains the whole core and almost all the radioactive products. After severe accident, core will be molten due to loss of cooling and relocate to the lower head of vessel finally. In this situation if the integrity of vessel could be maintained by various methods, mass fraction of radioactive products will be retained in the vessel and the accident consequence will be mitigated. After Fukushima accident, Chinese government raises the "practically elimination" request to the NPP in plan, and it is a meaningful approach to meet this request by maintaining the integrity of vessel after severe accident. In this paper, the methods of maintaining integrity of vessel implemented in mainstream advanced PWR are classified and introduced by the decay heat removal approach.

Increasing cooperation through greater interdependency of the organizational networks structures is a topical issue for a diverse range of industries, including the energy sector However, despite the advantages of such form of activity, Russian organizations do not tend to cooperate. An extensive analysis of the techno-economic network of the Russian power sector innovation ecosystem made it possible to identify hub-organizations which could be regarded as the catalysts for partnership development. Hence, the purpose of this paper is to elaborate the mechanisms of target network creation behind hubs' involvement in the network expansion. Thus, it could provide a solid foundation not only for an increased number of partnerships but could also serve the purpose of embedding companies in the strategic activity ultimately enabling them to achieve competitive parity with the rest of the world.

The NEXUS at Appalachian State University, NC, USA is a multidisciplinary team of faculty and students housed in the Department of Sustainable Technology and the Built Environment whose research lies at the intersection of agriculture, energy, and natural resources. NEXUS is developing inexpensive and efficient sustainable energy greenhouse heating technologies that provide affordable and sustainable means to improve the food-growing capacities and the standard of living for farmer communities in rural Appalachia while reducing the use of fossil fuels. This is done by using on-farm biomass resources/wastes such as agricultural waste and wood chips to produce energy. Growing season extension with heated greenhouses increases the availability of local food throughout the year, expands available markets and increases farmers' profits. The 7 m by 10 m greenhouse (conventional hoop) includes an above ground 5,700-liter water storage tank and an aquaculture pond. It is supported by a small-scale pyrolysis system, an anaerobic digestion system, solar thermal, and compost heating. The heat from various heating methods is delivered and stored in the water storage tank inside the greenhouse. An Arduino module controls the flow rate of water from the tank to various heat exchangers based on temperature differentials. A closed loop heat exchanger circulates heated water from the tank to the aquaculture pond to maintain an optimal temperature for tilapia growth. The pond also acts as a thermal storage, and holds/distributes heat to the greenhouse. The main purpose of this study is to test the integrated sustainable energy heating system for growing season extension with less energy cost. Our preliminary result shows that compared to a conventional space heating system, about 30% of energy was saved to keep the greenhouse temperature available for growing by radiation from the water storage tank.

In order to know the risk of fire of disaster waste, radioactive waste and recycled materials, thermal analysis and gas emission test were conducted. Huge amount of disaster waste and radioactive waste were produced after the Great East Japan Earthquake (March 2011). During recovery work, we experienced many fires and accidents due to spontaneous ignitions from massive disaster and radioactive wastes. Some of wastes should be recycled for biofuel and constructive materials. To know the risk of ignitions and fires, we conducted risk evaluation for these materials using high sensitive calorimeters and gas emission. The investigation process and results are shown. Microorganism in the wastes caused faint heat generation which might be a trigger of fires. However disaster wastes are much safer than most solid biofuel, because disaster wastes contained large amount of incombustible materials.

With the growing importance of environmental criminal responsibility system, other countries connected environmental law with system design. The international community attaches importance to the legislation of environmental criminal responsibility, and pays more attention to new criminal sanctions other than traditional criminal sanctions, for each country has a certain guidance and reference significance.

Maximum energy utilization and high-power density are critical to solar powered aircraft energy system. SiC devices have the advantages of high frequency and high temperature and it is very promising in the aspect of the development of high temperature and high-power density converter. This paper designed a 1.2 kW SiC based power controller using interleaved two-switch buck-boost converter, analyzed the working process of the converter, put forward small signal model and discussed three mode control strategy, and achieved smooth switching among all modes and maximum utilization of power energy. Experimental results demonstrate that the converter module has the power density of 2.4 kW/kg.

Electrical load management is undoubtedly an integral and paramount component of power industry functioning. Electric and hydrogen vehicles are not an exotic vehicle today and the most perspective for solving this problem. The paper studies the impact of advanced environmentally compatible vehicles on electric power system expansion. The potential of their use as load-controlled consumers is assessed. The results of study in the area of electric power system expansion optimization considering this potential for electricity consumption control are presented.

The toolbox developed at Sandia National Laboratory (SNL), incorporates a range of well documented mathematical models, which provide scientific insight in to a number of aspects involved in the design of solar power systems. Of first and foremost importance is the need to acquire the capability to generate pre-processor input for the toolbox. As part of this strategy, the Solar Position Algorithm (SPA), developed at the American National Renewable Energy Laboratory (NREL), has been ported to evaluate parameters like zenith and azimuth angles for several geographical locations of Mauritius. Computations were carried out for two different seasons and for two locations, one at the University and the other at the 15 MW National Solar Power Plant, Bambous, Mauritius. The enormity of the task can be understood by realizing that we need both the solar position and weather data for several locations that would also vary with time and date. The importance of capturing such information on a high-resolution space (in order to generate Mauritius Energy Resource Map) is outlined in great detail. Experiments were carried out using solar module analyzer and the results obtained helped us to understand the pattern of variation of design parameters. This information is necessary for validation of the theoretical models. Sandia has implemented the package both in Python and MATLAB. To understand the fundamentals better, for the present, we are using the mathematical models, which are described in SNL documents, but in 'C' programming language. Engineering approach is more direct and an attempt has been made to generate insolation values for Mauritius, based on these formulations too, to serve some verification purposes. The full-scale implementation of SNL PV_LIB (Library of routines for simulation of photovoltaic energy systems), which provides a set of well-documented functions for performing a complete scientific analysis is likely to take at least another year or two.

In this study, a three-dimensional numerical model has been established and validated for microfluidic fuel cell (MFC) with flow-through porous electrodes. Systematically parametric analyses are performed to evaluate the effects of electrode aspect ratio on the reaction rate distribution in this energy system. Based on the results, the feasibility of improving the utilization degree of the porous electrode by alternating the electrode aspect ratio is demonstrated and optimized electrode aspect ratio is derived for this energy system.

In order to study the effects of application of fresh carbon on distribution in soil aggregate fractions of red soil and lime concretion black soil, the stable carbon isotope (δ¹³C) technique was used, and explore the dynamic variation and distribution of soil organic carbon(SOC) in soil aggregates during ¹³C-labelled rice straw decomposition by an indoor incubation experiment. This experiment was put under incubation at 28°C for 120 days, which included two treatments: CK (no straw) and Str (added with 1% straw), all samples were separated into four aggregate-size classes (>2000, 2000~250, 250~53, <53 μm) by wet sieving in the different incubation period, while soil aggregates in different size fraction and organic carbon in soil aggregates were determined. The results showed that the δ¹³C value of organic carbon in different particle-size water-stable aggregates of Str treatment was significantly higher than that of CK treatment, the δ¹³C value varied greatly both in red soil and lime concretion black soil, but the turnover rate of native SOC was slow and the degradation degree was relatively close. The quantity of new organic carbon supplied by rice straw found in different levels of aggregates followed a same increasing order of 2000~250 μm < (>2000 μm) < (<53 μm) < 250~53 μm in red soil and lime concretion black soil at 120 days, which further indicates that the added fresh carbon was mainly accumulated in small-sized soil aggregates. The result shows that the addition of rice straw could increase soil organic carbon content in all sizes of aggregates, which provide theory basis for soil quality improvement and organic carbon recycle.

Aiming at the current situation of high LCOE (Levelized Cost of Energy) of photovoltaic (PV) power generation system, this paper focused on the calculation of optimal LCOE and capacity ratio of PV arrays to inverters on single axis tracking system in different solar resource areas. The effects of solar resource, system investment, land and finance on the optimal capacity ratio were analyzed, the conclusion was deduced at the end of this paper.

The partial pressure of hydrogen is a significant factor for dark fermentation. The effect of reduced hydrogen partial pressure as well as different operation condition was investigated in this study. The results showed that hydrogen production enhanced when partial pressure reduced. The reduction of hydrogen partial pressure (reduced by 20%, interval=2h) increased the efficiency of hydrogen production by 54%(202.15mL) compared with the control group. The kinetic parameters of hydrogen production show that the maximum hydrogen production (P_max) and the maximum hydrogen production rate (R_max) were increased by the reduction of hydrogen partial pressure. And the hydrogen production delay time (λ) decreased. Moreover, with the decrease of hydrogen partial pressure, ethanol content gradually increased, acetic acid/ethanol ratio decreased, total VFAs increased. The compositions of soluble microbial products as well as ecological factors were affected by hydrogen partial pressure.

With the fast development of electric railway, harmonics and reactive power problems caused by electric locomotive load remains to be further improved. This paper presents a novel power quality conditioner based on multiple H-bridges with photovoltaic power. The proposed structure utilizes a hybrid cascaded 81-level converter in series with a PWM converter to achieve a high-voltage and large-capacity power quality conditioner, and photovoltaic power connects with the DC bus side of the hybrid cascaded 81-level converter to reduce active consumption for electric railway. The fundamental voltage of the hybrid cascaded 81-level converter is controlled by the traction network. The active component of the PWM converter output current is controlled by DC link voltage of the hybrid cascaded 81-level converter, and its reactive and harmonic components are controlled by reactive and harmonic currents from the load. The system structure, working principle and control method of the novel power quality regulator are analysed. A single-phase traction system simulation model is built in MATLAB/Simulink. Simulation results are presented to verify the feasibility and effectiveness of the proposed PQC.

This study was based on the problems existing in the hydropower unit reliability assessment. Through the discussion of the ways and methods of hydro turbine reliability evaluation, and the reliability evaluation index, some proposals are provided to improve the reliability management level of hydropower enterprises.

This paper aims at boosting the sustainable use of biomass renewable energy potential in Cameroon to generate electricity especially for its rural communities. In this country, woody biomass resources are primarily used for cooking and heating and we aim to increase its utilization through power generation. For this reason, an experiment using a gasification power generation system which was designed and assembled in Ashikaga University was used. The power generation capacity of this system is 20 kW. It is connected to a gas analyser in order to monitor the generated synthesized gas. The rotary engine which was used in this case was operated at running speed of 2800 rpm under two different woody biomass feedstock methods, which are the close-top and the open-top methods. It was then observed that the close-top operation generated more electric power compared to the open-top operation. During this process, the temperatures at the reduction and oxidation layers were both monitored and higher temperatures were obtained during the close-top operation.

Energy saving of the hydraulic system is significantly realized by improving the efficiency of the pump. The slipper/swashplate lubricating surface is one of the main energy consumption parts in axial piston pump which is always used in the hydraulic system. Being a hydraulic bearing in axial piston pump, the slipper/swashplate pair exerts both the bearing function and the sealing function under the oscillating working condition. Because of viscous friction and leakage flow, power loss of slipper/swashplate is also one of the main power loss sources in axial piston pump. A precise model of lubricating surfaces, which includes oil film thickness, dynamic pressure field, load carrying ability and energy dissipation, is indispensable to develop more effective lubricating surface morphology. An elastohydrodynamic lubricating oil film model has been established for the sliding surfaces between slipper/swashplate interfaces. The model includes an isothermal fluid model, micro-motion of slipper and pressure deformation of the bounding solid bodies using a partitioned solution scheme. The power loss model between the slipper and swashplate has been developed and solved by numerical analysis method. Numerical results demonstrate that the diameter of the fixed damping orifice in the slipper has an important role in power loss of slipper/swashplate except the axial rotational velocity and operating pressure. Finally, the accuracy of numerical results of power loss is verified by experiments.

An index, Resource Curse Intensity (RCI), is proposed to evaluate the degree of deviation between energy endowment and economic growth by taking national economic conditions into account for the energy system. The RCI is intended to provide a quantitative measure of what is regarded as the "resource curse", namely, the negative impact of natural resources wealth crowding out productive activities. Based on panel data from 30 provinces/cities from 2001 to 2010, empirical analysis is carried out with the convergence method from neoclassical economics to shed light on the temporal-spatial distribution, evolutionary trends, and convergent determinants of China's RCI for energy. The findings of the study indicate that the index has become significant in China since 2009; compared to other factors, technological progress poses notable positive effect while energy structure, openness Level, and administrative have weak influence on the curse convergence; an inverse correlation shows up between the industrial structure and convergence effect; moreover, club convergence is found in the eastern and central regions but western region in mainland China.

The steam-water separator is a vital device of the steam generator in nuclear power plant. Its separation performance greatly influences the efficiency, safety and reliability of the power station. When the droplet moves in separator, the droplet can collide with the separator wall, and the secondary droplets may generate when the collision velocity of the primary droplet is sufficiently large. To investigate the effect of secondary droplet on separation performance of the separator, the simulation is conducted using droplet motion model and generation model of secondary droplet. The trajectories of both primary droplet and secondary droplet are presented. The effect of the secondary droplet on the separator separation efficiency is analyzed. The results can guide the design of the separator, where both of the droplet motion and the secondary droplets generation need to be considered.

The phenomena of droplet-surface interaction have important applications in many industrial fields. In different scenarios, the viscosity of the liquid droplet that impacts on the solid surface is usually different, and the viscosity of the droplet has a great impact on the results of the droplet impingement. In this paper, the phenomena of single droplets with different viscosity (deionized water, 50% glycerol/water solution, 99% glycerol/water solution) and different Weber number (We) in the range of 147.6-939.4 impacting on a flat stainless-steel plate were recorded by a high-speed camera at 4,000 fps, and the spreading behaviour of droplets with different properties were observed. The effect of droplet viscosity and Weber number on the droplet spread on the solid surface is quantitatively analysed, and the results demonstrate that the increase in Weber number has a promoting effect on the maximum spreading diameter, whereas the increase in viscosity has the opposite effect. For high viscosity drops (99% glycerol/water solution), retraction hardly occurs after the maximum spread diameter is reached. Finally, empirical correlations of the normalized maximum spread diameter as a function of the Weber number for droplet of different fluids were derived based on the present experimental data.

This paper examines the effects of thermally reduced graphene oxide (rGO), incorporated in the titanium dioxide (TiO₂) photoanode, on the performance of anthocyanin dye sensitized solar cells (DSSCs). While anthocyanin based DSSCs are cost effective, their efficiency tends to be low. In this study, rGO-TiO₂ nanocomposites with different rGO weight fractions were synthesized. Their surface morphology was studied with Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Electrical conductivity of these nanocomposite layers were measured with the four-point probe method. The current-voltage characteristics of the DSSCs made with these nanocomposites along with anthocyanin dye from blackberries, a carbon counter electrode, and an Iodine based electrolyte were studied. It was found that the addition of rGO, at low weight fractions, increased nanocomposite conductivity, the solar cell short circuit current, and cell efficiency. Peak efficiency, increased by 45.7% of that with no rGO, was achieved with a photoanode layer containing 0.004 wt% rGO.

In this paper, the internal friction for the viscoelastic materials such as asphalt is analyzed theoretically. The variation of the strain energy and internal friction per period when an alternating stress is applied to the viscoelastic material is discussed which shows that the storage and release of the strain energy are alternately carried out. The internal friction per period is related to the loss modulus. However, it is independent of the energy storage modulus. In addition, the energy storage modulus, loss modulus, tangent of loss angle and internal friction for four viscoelastic constitutive models, i.e., Maxwell model, Kelvin model, Lessersichi model and Jeffreys model, are calculated from which we know that they are all the functions of frequency. When the frequency is zero, the internal friction for the Kelvin model and Jeffreys model are zero, while the Maxwell model and Lessersichi model are infinity.

Making energy carry information is the major research direction of achieving Energy Internet. Besides, electric energy has incomparable advantages in energy transmission efficiency. Therefore, the future of Energy Internet is the Power Internet. Then, accurately predicting the consumption of power becomes the foundation of Energy Internet. Depending on the extraction, transformation, loading (ETL), Hadoop, Oracle and OLAP technologies. This paper establishes energy, electricity, economy forecasting and warning system. By considering the data of energy, electricity and economy together, a new economic power transmission model is established. The traditional econometric methods, such as OLS, AR, MA, ARMA and X11, are all employed during the estimated process. The estimating results demonstrate that the goodness of fits of the new models are all approximately equal to 0.998. The electricity consumption of industry is 1935224.28*10⁴ kWh in the 3rd quarter and 2,846,897.0 *10⁴ kWh in the 4th in 2017, respectively.

In order to solve the problems of difficult and unintelligent charging of the mobile robot after the exhaustion of battery power, this paper applies wireless power transfer (WPT) technology to the charging of robot, and designs a wireless charging system that meets the characteristics of the robot. In this paper, the basic theory of wireless charging system is analysed. The expressions of output power and efficiency are derived, and the expressions above are input as code into MATLAB. By the MATLAB code, the effects of parameters such as coil inductance and coupling coefficient on the output power and efficiency of the system are studied, and the relevant parameters of the system are determined. Through MATLAB Simulink simulation, it is found that the voltage of the battery pack of the robot is too low and frequency split occurs. This paper proposes a frequency control strategy to deal with the frequency split phenomenon. The overall scheme of the robot wireless charging system design is given, and the design and hardware implementation of the transmitter controller, the energy coupler, and the receiver controller are given respectively. Finally, through the installation experiment, the correctness and practicability of the robot wireless charging system designed in this paper are verified.

Since ancient times, "Silk Road" has been the important trade route linking Asia, Europe and Africa. In 2013, President Xi Jinping proposed a new strategy for building the "New Silk Road Economic Belt" and "21st Century Maritime Silk Road" on the ancient Silk Road. Together, they are also called "One Belt, One Road." Its establishment aims at deepening the economic cooperation between our country and its neighboring countries and neighboring regions, including language, culture and religion. Since the "One Belt, One Road" economic belt involves as many as 64 countries in the country, the legal provisions, the status quo of the environment and the political factors are numerous and difficult to adjust. After collecting the data of important countries along the economic belt, this paper analyzes and contrasts them. Then it studies the existing international protection mechanism, sums up the challenge of establishing the international protection mechanism and feasible suggestions to promote the healthy and steady development of "One Belt, One Road" economic belt. At the same time all countries are developing their economies, how to reduce environmental pollution and maintain ecological balance are the primary issues in the development of "One Belt, One Road" economic belt.

Heat waves that are the result of climate changes have become an increasingly intense and therefore dangerous for human health and life. In the countries of moderate climate such as Poland, which have never before been experienced by such phenomena, residential buildings are usually free of overheating systems. In this paper authors propose a passive cooling method using the ground under thermally uninsulated floor slab as a heat sink for cooling the inside air during hot summer. The paper presents current knowledge of the authors gained as a result of theoretical analysis, fully confirmed by experimental research in two terraced rooms differing from each other only by the type of floor construction. Authors additionally presented the simulation results obtained for detached houses, which took also into account the effect of blinds in windows and increased night ventilation. The lack of ground floor thermal insulation significantly decreases the indoor air temperatures in the room with negligible "cold floor" effect. The duration of heat wave did not affect the effect of temperature reduction. Despite of the significantly difference in energy demands, it can be compensated by renewable energy sources.

Nowadays geothermal projects must face a challenging competition from variable renewable generation projects, such as PV and wind power plants, almost all over the world, and usually their biding offers cannot compete with traditional or alternative renewable energies. The efforts of this paper aim towards finding new approaches to assess geothermal energy in order to properly consider their unique technology advantages as well as a longer term for assessing the availability of this technology to strengthen the power systems. The technical feasibility of installing a geothermal-power plant is highly dependent on the availability of an adequate geothermal resource and energy market competitiveness against other technologies. In this work, the geothermal energy role is evaluated in order to achieve the decarbonisation of the Chilean Energy Matrix in different scenarios, including the complementary use of geothermal and CSP units.

Dry-type Air-core Reactor is widely used in power system. It is an important reactive power compensation equipment in power system. In recent years, the dry air reactor has suffered a number of failures in operation. The failure occurred most frequently in the dry-type air-core reactor and we cannot detect the inter-turn short circuit faults in neither single wire winding nor multiple wire windings. The research and protection of reactor faults is almost in the blank at present. This paper presents the method of collecting the unbalanced current between bus-bars to detect the winding inter-turn short circuit faults. The numerical simulation of short circuit model between different windings of the reactor is carried out. Current-differential analyzed on the unbalanced current data of experiment are used to determine whether an inter-turn short circuit occurs. The results indicated that the closer the short-circuit is to the end of the reactor, the greater the unbalance current is. The changes of collecting current between bus-bars are much larger than the total current. Short-circuit current redistribution only occurs between two windings after the short circuit. The circuit in other windings is almost unchanged.

Doubly-fed induction generator (DFIG) with dual Pulse-Width Modulation (PWM) converter cannot maintain the active power balance or voltage stability of the power grid self-synchronously because of lacking mechanical inertia and mechanical damping. The virtual synchronous generator (VSG) technology can help solve this problem through simulating the mechanical equation and electromagnetic equation of synchronous generator to control the grid-connected converter. However, under the common first-order virtual inertia link used in the VSG control scheme, while DFIG providing active power support, there exists second frequency dip and the rotor speed recovers slowly, which is not conducive for DFIG to provide continuous and effective virtual inertia support. In order to overcome the drawbacks as well as avoid second frequency dip, this paper puts forward a virtual inertia control strategy of DFIG with additional inertia and damping torque. The additional torque is achieved by proportional-derivative (PD) controller with rotor slip as an input signal. Simulation results on DIgSILENT/powerfactory platform show that the proposed control strategy is effective to reduce frequency deviation and recover the rotor speed faster without second frequency dip phenomenon.

Photovoltaic (PV) technology has been widely used as a source of electricity for household appliances, electrical vehicles, industrial and commercial systems. Energy yield by a PV panel installed in the field is dependent on the amount of photon reaching its solar cells. One environmental factor playing an important role to reduce PV power production is dust. Dust particles generated by human work and natural processes reflect, absorb and scatter solar radiation. This research examined dust effect on power degradation of several PV technologies commonly found in West Timor islands including mono-crystalline silicon (mc-Si), amorphous silicon (a-Si), and polycrystalline silicon (pc-Si) technology. Dust collected from a PV power plant in the island was coated artificially onto the front side of the PV samples. Furthermore, electrical parameters of the panels were examined using a SPIRE 5600SLP solar simulator. A HP spectrophotometer was applied to measure optical property of the dust. Results revealed that maximum power output value of all modules decreased as dust concentration increased. There is a linear relationship between PV output degradation and dust density <0.3 mg/cm². This is in line with the dust transmittance value which is linear within the density <0.3 mg/cm². In addition, it was found that different PV technologies shared different respond to the power output reduction. According to the results, at the same density of dust collected from the site in West Timor, a-Si PV module exhibited the largest maximum power output degradation followed by pc-Si and mc-Si technology.

In series with each other, the cascaded H-bridge multilevel inverter (CHML) could apply same or different DC bus voltage. By modifying the isolated DC voltage supplies of a traditional 7-level 3H-bridge inverter with voltage ratio 4:2:1, the proposed inverter outputs a near-sinusoid, 15-level resoluted, stepped voltage with low distortion. The pros and cons of different modulation schemes including PWM, staircase modulation and hybrid PWM are analyzed on switching losses, low order harmonics and THD, which are then verified by Saber simulation.

Experiments were used to explore the cyclic variability of a CNG engine. The experiments were conducted on a large bore (12V190) engine fuelled with pre-mixed natural gas. The influences of the ignition advance angle, the excess air ratio and the ignition energy on the cyclic variability were investigated. At each test condition there were acquired in-cylinder pressure traces of 100 consecutive cycles. Cyclic variability was quantified by the variation of indicated mean effective pressure (IMEP) in this paper. The experimental results showed that the cyclic variation was increased while increasing the dilution levels. And, the cyclic variation was reduced with the increase of the ignition advance angle. Meanwhile, the cyclic variation could not be significantly reduced just by increasing the ignition energy on the specified engine. The reason can be that the most important influence exerted by the ignition energy is the formation of early flame kernel. In order to significantly reduce the cyclic variations, there is also necessary the improvement of the gas mixture's motion state in the cylinder.

This paper presents an evaluation of the transfer coefficient of a reversible PEM fuel cell by using the Lagrange's undetermined multiplier technique. In a first step, the technique using the activation polarization was presented. Then we put the stress on the Lagrange's undetermined multiplier technique. The mathematical bases of this method are presented. Subsequently, an experimental determination of the transfer coefficient was carried out by using the two methods. For that purpose, a kit called Hydrocar, combining a solar panel, a reversible PEM fuel cell (which is a combination of fuel cell and electrolyser), hydrogen and oxygen storage containers, and a 3 Volts alkaline battery, was experimented. The experimental study of the solar panel was made. Some parameters of the solar panel were determined, such as the fill factor FF, the efficiency η, the short circuit current I_SC, the open circuit voltage V_OC, the maximum power P_m, and the series resistance R_s.The internal resistance R_i and the optimal resistance R_opt of the fuel cell were determined. Finally, experimental study of the electrolyser and the PEM fuel cell was performed. By using the activation polarization, an evaluation of the transfer coefficient was made. Then an evaluation of the transfer coefficient was made by using the Lagrange's undetermined multiplier technique which takes into account the ohmic polarization, the activation polarization and also the current-power characteristic of the fuel cell.

This article is about the realization and experimentation of an elliptical solar cooker. This prototype has a single focus and a reflective surface made of galvanized sheet. Its opening diameter is 120 cm and focal length is 60 cm. In a first step, Cooking Tests of six eggs in 0.5 L of water were carried out by fixing the maximum cooking time to 2 hours. The first results showed that the cooking of the eggs was partial. Despite adequate illumination, the temperature 82°C, at which starts the cooking of certain foods according to "International Solar Cooker", could not be reached. Thus, a glass cubic box was built that served as an envelope for the pan. In 60 minutes with this new configuration, a temperature of 88.23°C was reached, which is widely more than the 82°C required. After 80 minutes of cooking, a temperature of 92.12°C was reached. Finally, after 80 minutes of cooking, all six eggs were completely cooked. In the second step, the reflective surface was coated with mirror. In such configuration, seven eggs were perfectly cooked after 40 minutes of cooking in 0.5 litres of water. 250 grams of rice were also cooked after 80 minutes of cooking, in 0.50 litres of water. Experiments were made simultaneously with a parabolic concentrator solar cooker. Efficiency calculations showed that the ellipsoidal concentrator solar cooker and the parabolic concentrator solar cooker have almost the same efficiency, with a slight advantage for the ellipsoidal concentrator solar cooker.

In this paper, a switched reluctance motor (SRM) drive system using variable excitation period single-pulse control for independent-wheel electric vehicle (EV) is presented. A novel single-pulse control oriented maximum efficiency and fast adaptation using excitation mode shift according to load is examined for operating stability analysis of this system under the conditions of different speed references. In addition, comparison experiments of the proposed control and a voltage PWM control are described to confirm the operating performance of experimental miniature EV system in actual operational environment.

This paper studies the performance of UEI (Ubiquitous Energy Internet) by means of its energy supply-demand matching degree. First of all, the energy supply-demand matching degree of UEI is defined, and then the information entropy of energy supply-demand match degree is defined either by use of Shannon's information entropy theory. On the basis of these two definitions, the energy matching degree information entropy of the distributed Energy Internet is defined. By the study of information entropy characteristic and energy supply-demand matching degree, the evaluation model of energy supply-demand matching degree of UEI is provided, and the performance of UEI is evaluated. Finally, the effectiveness of this evaluation model in solving the supply-demand performance evaluation problem of UEI is proved by an example.

In this paper, the exergy costs apportion problem of SIMO (single input and multiple outputs) energy produce node in UEI (Ubiquitous Energy Internet) is studied. The traditional exergy costs model is not suitable for solving the exergy costs problem in the UEI scenario. Considering the main and auxiliary output exergy, the energy expenses and non-energy expenses divide additionally. Then two apportion rules that used for solving exergy costs problem in the process of energy produce are provided. At last, a new exergy cost share model is built. Comparing this new exergy cost model with traditional exergy cost model, the main output exergy costs are higher and the auxiliary output exergy costs are lower. The exergy cost calculated by the new exergy cost model is closer to the actual exergy costs of the UEI produce node. This exergy costs could be a more reliable cost data in the process of production decision in a Ubiquitous Energy Internet produce nodes.

This study presents the bases of a Preferential Plan obtained through a new methodology for energy planning, the IRP (Integrated Resources Planning of Energy) for the Power Sector, developed in GEPEA/EPUSP, Brazil. This Integrated Energy Resources Preferential Plan is a systemic compilation of energy resources obtained through an integrated in-time and geographic energy planning, denominated Integrated Resource Planning. The plan is developed using the methodology of Environmental and Energy Inventory; Listing and Drafting of Energy Resources; Calculation and Valuation of Energy Resources Full Potentials, Full Cost Analysis, Demand Forecasting and Resources Integration, after which the construction of plan effectively starts. Finally, the IRP Preferential Plan is a continuous up to date plan and a proposal for an alternative methodology for an energy planning for the power sector aimed at sustainable development through a complete overview among energy, environment and society, with its balanced importance.

With the development of power electronics, more and more power electronic devices are being put into use in the power grid, causing serious harmonic current pollution to the power grid. Active power factor correction (APFC) technology is an important technology for solving harmonic current pollution and has been widely studied and developed. Three-phase PFC based on PWM technology can eliminate harmonic pollution on the grid side and improve power factor and work efficiency. Traditional three-phase PFC generally adopts double PI control strategy of voltage outer loop and current inner loop. However, this traditional control strategy has been unable to adapt to the increasingly complex grid situation. This paper proposes a control strategy that adopts PI controller for voltage outer loop and fractional-order PID controller for current inner loop. And through the Simulink simulation experiment, the result proves that the improved three-phase PFC control strategy presented in this paper has a more stable output voltage and less ripple compared with the traditional dual PI control strategy.

For Double-Fed Induction Generator (DFIG) wind farm systems with Static Synchronous Compensator (STATCOM), by optimizing multiple proportional integral (PI) controllers parameters of DFIG and STATCOM, the performance of the wind power system is significantly improved and the voltage of point of common coupling (PCC) is quickly restored when a low voltage due to a grid fault. Chaos orthogonal particle swarm optimization is proposed to make the integral time absolute error (ITAE) of active power of DFIG, DC-link voltage of converter of DFIG and voltage of PCC minimum. The orthogonal method is used to get the range of parameters and identify the weight relations between different indicators. And then the chaos algorithm is used to initialize the algorithm. Finally, the particle swarm optimization (PSO) can effectively improve the efficiency of the optimization. Based on MATLAB/Simulink, the simulations of wind farm containing STATCOM incorporated into the infinite system under different conditions both show that the application optimized PI controllers have good dynamic performance, which validates the effectiveness of the optimization algorithm.

An experimental study on air gasification of straw was conducted in a tube furnace. The effect of the equivalence ratio (0.1-0.4) and temperature (600-900°C) on various gasification results, including gas composition and vaporized residue was investigated. The equivalence ratio(ER) appeared to have a significant effect on the result of gasification, and the experiment demonstrated the optimal gasification parameters (ER is approximately at 0.2, T is at 800°C). Under this operating condition, the residue after gasification of straw air accounts for about 7.39% of the original straw material, the combustible components in the gasification synthesis gas occupy 71.01% of the total volume, the H₂ content is 17.49%, the CO content is 38.02% and the CH₄ content is 15.49%. The intersection of the CO and CO₂ line charts has realistic implications for the selection of the optimal gas conditions (T, ER) and the increase of gasification efficiency.

With stringent environmental regulations and growing concerns on energy consumption of the marine transport sector, there is a serious effort to make on board energy system more efficient. Improving fuel efficiency is conceived as a sustainable measure in terms of reducing greenhouse gas (GHG) emissions and overall marine energy use. As such, electrification of ship propulsion has been introduced as a solution for operating at higher efficiency and hence more saving fuel. However, energy efficiency in the context of marine transport is to be more stringent over time as required by International Maritime Organization (IMO). The energy performance indicators to evaluate such requirements include Energy Efficiency Design Index (EEDI) and Energy Efficiency Operational Indicator (EEOI). Several energy efficient methods are therefore proposed to further improve fuel efficiency on board electric vessels. These involve integration of energy storage system, implementation of DC distribution, optimal power distribution and scheduling as well as various operational practices that are currently applicable for existing conventional vessels. The paper summaries the concept of ship energy efficiency in terms of the standard indicators and provide a brief review on the energy efficiency improvement strategies published in literature. The aim of the review is to analyze the methods that are potential to incorporate into the autonomous system of all-electric vessels. The results show a significant variation in reported efficiency gain and thus a combination of various methods is suggested to achieve full potential for emissions reduction.

This study numerically explores the diffusion rules of pollutants in an idealized urban street canyon where photochemical reactions are present in the neighbourhood. The airborne pollutants dispersion and reaction in street canyons are further investigated in this study. There is a relatively tense traffic pollutants release in urban neighborhoods, including nitrogen oxides and hydrocarbons. Photochemical reaction occurs at strong solar radiation, forming photochemical smog and other environment issues. We selected typical O₃ + NO→O₂ + NO₂ reactions. Effects of the pollutant source location on pollutant dispersion and reaction are also investigated. Numerical simulations were conducted on chemically activity reactive air nitrogen oxides in urban street canyons with W (street canyon wide)/H (building height) = 1. Provided three different locations from the line source street canyon bottom exhaust nitric oxide diffusion and react with ozone in the free stream. The chemical reaction has a significant impact on the concentration of pollutants in the valley volume.

Extracts of fluid non-volatile products isolated from the plastic layer of caking and low-caking coals of different genetic types by reductivity were first studied in detail using EPR-spectroscopy and gas chromatography-mass spectrometry (GC-MS) methods to reveal the components responsible for caking. According to a study of extracts caking additive selection was carried out. Choice of conditions and experimental verification of the effect of the proposed anthracene additive on the plastic layer formation has been established. The rate of coal decomposition in different periods of pyrolysis has been calculated by the results of derivatography method.

With the increase of the voltage level of the power grid and the increase of its capacity, the probability of transformer failure is getting higher and higher. In order to discover the early latency faults of transformers, a cross-entropy algorithm was proposed to optimize the support vector machines. This method established a support vector machine classification model and used the cross-entropy algorithm to optimize the penalty factor and kernel function parameters. The transformer fault data is used to verify the classification model and compared with the test results of other algorithms. The results show that the accuracy of this algorithm for oil-immersed transformer fault diagnosis has reached 86.7%, which is higher than that of genetic algorithm and particle swarm algorithm, and iterating over 6 times of the fitness curve tends to be smooth and takes less time. After many tests, the forecast results are stable.

Generally, urbanization processes occur in a disorderly way, especially in developing countries, and are characterized as one of the most aggressive human interaction with the environment. In the State of Minas Gerais, which consists of 853 municipalities organized in 17 Development Territories, approximately 85.3% of the population live in urban areas, evidencing the need for a good management of energy resources and an adequate disposal of Municipal Solid Waste (MSW). In this context, one feasible possibility is the use of biogas from landfills, which aggregates solutions for both MSW management and electricity generation, as it is being analysed in this work. The methodology proposed by the Intergovernmental Panel on Climate Change was used, which is generally based on population expansion in urban areas, as well as the rate of MSW per capita, considering the different arrangements of gravimetric composition. Next, the potential of electricity generation was presented considering the energy conversion efficiencies of four technological routes. The results showed that the use of motors as energy conversion technology presents the greatest technical feasibility for the implementation of such projects, reaching theoretical values of generation of up to 2,237.06 MWh / day in 2050.

For purpose of studying the influence of wave on the wind turbines, the causes of aerodynamic load fluctuation and the aerodynamic torque ripple of hydrodynamic frequency is analysed in the mechanism by using the wave model. According to the formation mechanism, the existence of the ripples is verified on GH Bladed platform. To reduce the ripples caused by wind shear, tower shadow and waves of offshore wind turbine, a pitch control strategy is presented in this paper. Firstly, the integral gain of the top tower vibration acceleration signal is combined with the reference pitch angle value to reduce the uniform pitch. Then designing a low-pass filter to filter out the 3P output power ripple of the wind turbine, and converted into adjustment of individual pitch angles of three blades according to rotor azimuth, and superimposed with the changed uniform pitch angle at last. Simulation results indicate that the designed pitch control strategy can not only alleviate the 1P aerodynamic load ripple, but also suppress the aerodynamic torque and output power ripples at 3P and hydrodynamic frequency. The proposed pitch control strategy can reduce wind turbine fatigue loads and improve the output power quality.

The construction of energy-saving transmission network contributes to both economic benefits and greenhouse gas emissions reduction. To reflect the energy-saving effects better, in this paper, a comprehensive evaluation index system and evaluation method for the energy-efficiency effects of energy-saving transmission network are studied. First, an evaluation index system for energy-saving transmission network is established, including indices of energy-saving effects and indices of low-carbon effects. Then, through specific steps of index data preprocessing, index data correlation analysis, index weighting methods, agglomeration model formulation, and comprehensive evaluation results display, the comprehensive evaluation model is formulated. Finally, case study results verified the feasibility and effectiveness of the proposed evaluation index system and assessment method.

High penetration of intermittent photovoltaic (PV) generation in medium and high voltage distribution network (DN) has caused uncertainty in power flow. Under this circumstance, great challenges have been put on reactive power control and voltage regulation in DN. In this paper, focusing on reactive power control of PVs and voltage regulation, a coordinated control of PVs in medium and high voltage DN is proposed based on voltage partitioning and pilot nodes selection. Firstly, three indices are introduced to evaluate performance of voltage partitioning, that is, redundancy rate of reactive power within a partition, strong coupling within a partition and weak coupling within partitions. Secondly, indices of observability and controllability are adapted to select pilot nodes. Then the control strategy of PVs in medium and high voltage DN is proposed according to results of voltage partitioning and pilot nodes selection. Case study results verified the feasibility and effectiveness of proposed control strategy.

In a magnetic coupling resonant wireless power transfer (MCR-WPT) system, energy is transferred between transmitter and receiver coils with same natural resonant frequency ω₀. Studying energy transfer mechanism is the theoretical basis of MCR-WPT control. This paper takes the MCR-WPT system with two coils as the research object. Firstly, the model of the system is established. Then, combined with the theory of waves, the change of the capacitor charge of the two resonant circuits is analysed, which is drawn up during the linear superposition of two different frequency modes and is also a modulation wave with a specific system resonant frequency ω_s as the carrier frequency and ω_Δ as the modulation frequency. Where ω_s is different from ω₀. Next, the energy of the two resonant circuits is analysed, which is transferred with the beat frequency 2ω_Δ. Finally, ANSYS Simplorer and Maxwell co-simulation is used to verify the correctness of the theory of this paper.

The dewatering sewage sludge from the Wastewater Treatment Plant in the West of Jinan was chosen as the research object. Its physical and chemical properties were analyzed to investigate the passivation effect of fly ash on the four kinds of heavy metal (Cu, Ni, Zn and Pb) in sewage sludge. The results showed that the contents of organic matter, N and P were rich in the sludge and contents of the four heavy metals were accord with the standard "Disposal of sludge from urban wastewater treatment plant-Quality of sludge used in gardens or parks standard" (GB/T23486-2009). The four kinds of heavy metals could be passivated effectively by adding fly ash. The optimum effect could be obtained by adding 10-20% fly ash. It's unfavorable to the passivation of Zn when the applied amount of fly ash exceeded 40%. The passivation effect of fly ash was mainly ion exchange and raising the pH to convert heavy metals into insoluble salts.

Global climate change has been an impending cosmopolitan issue. As the basic part of the city, urban residential area is the basic space for the use of sustainable ideas to promote the construction of low carbon city. Along with urban expansion, social polarization and significant change of social space in China, the decline tendency of central city become significantly faster. Faced with the double test between climate change and residential area recession, traditional renewal methods no longer meet the needs of urban sustainable development. The urban renewal modes need a major transformation, and Low carbon renewal is an effective way not only to slow down the decline of residential areas but also promote sustainable development of the city. To put forward an analysis and optimization methods for low carbon renewal, we proposed a low carbon renewal system from six aspects: layout planning, road and traffic, architecture planning and design, environment engineering, municipal engineering and construction management. Moreover, we used Analytic Network Process (ANP) to analyse the internal feedback of the system. At last, the optimization process of residential low carbon renewal was proposed.

A 3D DNS numerical study with detail chemistry mechanism has been carried out to investigate turbulent premixed combustion with oxyfuel mixtures under similar operating conditions as happened in spark ignition Internal Combustion Engine (ICE). H₂O and CO₂ are adopted as the dilution in oxy-fuel combustion. The temperature profiles of oxy-H₂O and oxy-CO₂ combustion are consistent with those of air-fired conditions in laminar premixed flame when the molar fraction of H₂O and CO₂ are 73% and 66% in oxidizer, respectively. 79%, 67% molar fraction of H₂O and 79%, 56% molar fraction of CO₂ are also conducted to learn the effects of the dilution molar fraction on the process of flame propagation. With the molar fraction of dilution increases, the mass of C₂H₂ increases the flame propagation speed and the mass of CO does an opposite influence. With the investigation for effects of turbulent intensity under conditions of 73% H₂O and 66% CO₂ with the initial u' of 0.8, 1.6 and 2.4 m/s, respectively, results show that the turbulent intensity has little effect on the formation of CO. It is also demonstrated that for oxy-fuel combustion, due to the disparity in laminar flame speed, an appropriate u' is necessary to keep consistent with the flame propagation speed meanwhile to maintain suitable temperature profiles.

This paper proposes a Cloud Energy Management System (C-EMS) for the building-scale hybrid microgrid. The building-scale hybrid microgrid is composed of renewable energy generators, charging piles, dc and ac loads, a diesel generator, energy storage devices, and a power electronic transformer connected to the ac power grid. The C-EMS is in charging of them. With the management of C-EMS, for the power system, the building-scale hybrid microgrid can be considered as a four-quadrant controllable node, which means it can be controlled to either generate or consume reactive and active power to the power system. In addition, based on wireless communication, the C-EMS receives the command of cloud management centre and make the microgrid operate at the assigned power. Therefore, numerous C-EMS can be managed via the cloud manage centre, which improves the controllability of the power system. The proposed C-EMS has been verified by the simulations carried out in Matlab/Simulink.

This paper presents a novel fault detection method for photovoltaic (PV) array using an improved two-stage Hampel identifier, which can quickly detect the occurrence of faults and locate them at PV module level. The fault detection method is implemented in a two-level wireless sensor network based distributed on-line monitoring system which is developed to monitor the voltage of each PV module and current of all parallel PV strings in real-time. The 1^st stage Hampel identifier detects and locates the faulty PV strings by comparing the instantaneous currents of different PV strings. The 2^nd stage Hampel identifier detects and locates the faulty PV modules by comparing the instantaneous voltages of different PV modules in the faulty strings. Experimental results show that the proposed method can successfully detect and locate faulty strings and modules in several faulty cases, including the line-line faults, the degradation faults, the partial shading faults and the open-circuit faults.

In order to improve the working efficiency of the photovoltaic (PV) array inspection system, the application of online monitoring systems for the PV arrays is quickly rising. In this paper, an online PV array monitoring combining with B/S architecture, Python language, and Flask framework is developed to monitor and diagnose the status of PV arrays which can display the data of the PV array and facilitate the staff to monitor the working status of PV array. When a fault occurs, the staff can also register the fault information on the website quickly. The developed system is composed of three parts: data acquisition, data transmission and PV online monitoring website. Firstly, the system uses the Raspberry Pi3 to collect the data when the PV array operates in maximum power point (MPP), and the acquired data is stored locally in the Raspberry Pi. And then, the data is uploaded to the PC side via the FileZilla server software and further transmitted to online monitoring website. Finally, the PV array online monitoring website displays received data, and perform the fault diagnosis of PV array using a kernel based Extreme Learning Machine (KELM). Experimental results show that the total classification accuracy for ten different operating conditions can reach 97.2%.

The power flows between the DC side and AC side of single-phase quasi-Z source inverter (QZSI) causes double-frequency (2ω) voltage ripple of capacitors, current ripple of inductors. This paper proposes a virtual self-injection active power filter (APF) ripple suppression strategy for the single-phase QZSI without changing the circuit structure, and the 2ω ripple is suppressed by controlling the shoot-through duty cycle based on the thought of ripple vector cancellation. The 2ω ripple model and its generation mechanic for single-phase QZSI are presented through the analysis of the power flows and small signal model for quasi-Z network. Simulation results verify the proposed ripple suppression strategy can effectively reduce the 2ω current ripple of inductors from 18.38% to 3.54%.

A vacuum still integrated with concentrating photovoltaic/thermal (VSICPVT) hybrid system for desalination is proposed in this paper. This system consists of a vacuum still, a concentrating photovoltaic/thermal (CPVT) module and a solar collector thus can produce freshwater and electricity simultaneously. Its prototype was established in North China Electric Power University (NCEPU), Beijing, China. In order to study the performance of this hybrid system with different inlet temperature of the vacuum still but with constant flow rate of saline water in the CPVT module, the experiments were conducted. And the electric efficiency, power, vaporization rate and freshwater yield of the system were analyzed.

Low concentration photovoltaic/thermal technology (LCPV/T) can supply both heat and power. Meanwhile, it has the advantage of low cost and less land occupation, therefore, the LCPV/T technology is suitable for integrating with building. In this paper, the outdoor experiment of a LCPV/T system is carried in June 9th, 10th, 14th and 15th. And the system performance was measured. Furthermore, the variation of thermal and electric efficiencies was analyzed. (4) The maximum thermal efficiency of LCPV/T system is 61.55% (100L/h), the maximum electric efficiency is 19.41%.

Indoor lighting is one of the most important consumer of the energy worldwide, driving to a high GHG emissions. Current state of the lighting system in the classrooms of the Technical University of Ambato (UTA), Tungurahua, Ecuador has been assessed in this work. A sample of classrooms were selected to quantify its illumination levels, with the Luxometer (Sper Scientific 850007), these data were computed by means of DIALUX software, whose generates the light distribution of different lighting systems scenarios and the lamps geometric distribution. Number of luminaires, luminous distribution and the energy efficiency value of the installation (VEEI) were compared among all the different cases, also a luminance analysis and the energy efficiency of installation was performed. First results show an important reduction of around 40% of the energy at present consumed, decreasing the emission of almost 200 tons of CO₂ equivalent per year.

A thermal storage flat-plate solar collector is designed to improve working stability of the solar air drying system, which consists of an absorber plate, a transparent cover plate, a heat insulation layer, phase change materials, a tube bank and a shell, etc. The daily thermal characteristics of thermal storage flat-plate air collector system were tested under natural conditions. The results show that heat storage flat-plate solar collector can effectively extend collector heating time, with daily heat efficiency reaching 49.8%, which is 4.6% up as compared to 45.21% of non-thermal storage heat collector.

According to the complementary nature of different power supplies, we proposed an optimal control system model based on model predictive control (MPC) in existing automatic generation control (AGC) framework to support effective operation of the AGC with the considerations of plug-in electric vehicles (PEVs) and controllable loads, to achieve full utilization of renewable energy sources, and to reduce the imbalance between supply and demand in the grid as far as possible. According to dynamics and update rate of power supplies at different time scales, as well as their actual power and energy constraints, MPC load distributor can find a solution of the MPC programming problem to well control the reserve capacities from the conventional generators, PEVs and controllable loads so that the tracking error of area control error (ACE) can be minimized. Massive simulation studies were performed under various control elements, such as different power combinations, different control reserve capacities, different ramp rates and different input control update rates. Simulation results are presented to demonstrate the effectiveness of the proposed method.

Refracturing is one of the important ways to restore well productivity and improve the ultimate recovery. Currently, the most effective way of refracturing is reorientation refracturing using diverter agent. In this paper, a water soluble diverter agent was synthesized by environmentally friendly non-toxic materials, the diverter agent particle size can be customized according to the fracture width, and it has good water solubility and can be water soluble completely after 4 hours of fracturing operation. Cores flow experiments show that the water soluble diverter agent plugging efficiency can reach more than 99% under over 40 MPa pressure, it has little harm effect on cores permeability, which satisfies the requirements of refracturing. The water soluble diverter agent was applied in filed for one well, the refracturing pressure increased 5 MPa after adding the water soluble diverter agent, which showed a good temporary plugging effect. The daily production after refracturing increased 1.98t, water cut decreased 10%. The results show that this refracturing mode is able to restore well productivity and decrease water cut.

What enterprises concern about is the fuel consumption of trucks which is emphasis. During practical operation, the most important factors which influence the fuel consumption of trucks are characteristics parameters of vehicle working condition and characteristics parameters of vehicle running. This paper selects road transportation vehicles in three typical cities——Chifeng, Baotou and Wuhai in region of Hohhot as object of research, to investigate and calculate isochronal data and survey the questionnaire in consumption of road transportation vehicles, summarizes characteristics parameters of vehicle working condition, builds the relationship model between fuel consumption of trucks and characteristics parameters of vehicle working condition, verification result indicates that the relationship model which is built can more correctly reflect the practical fuel consumption of transportation vehicles in Inner Mongolia, error rate is ±9.86%, By the point of view of the fuel consumption, come up with reasonable advice for selecting vehicle types and updating of road transportation vehicles, and follow up on helping vehicles to make decreasing fuel consumption come true.

Hydrotreating with dispersed catalyst at ppm level can provide an efficient, economical alternative to upgrading heavy oil. In this study, slurry phase hydro-conversion process is used for viscosity reduction. Several reaction conditions have been investigated using highly dispersed catalyst. Residue conversion of extra-heavy oil up to 30% can meet the viscosity requirement for shipping, and the conversion of bitumen from oil sands up to 50% can meet the viscosity requirement for pipeline systems. These hydrogenation reactions with temperature ranging from 390°C to 420°C had higher liquid yield (from 98.5 wt% to 93.2 wt%). In addition, hydro-upgrading product contains lower concentrations of impurities compared to raw feed. Based on our research, an efficient and environmental friendly alternative upgrading process with low process temperature was proposed. The process uses dispersed catalyst for extra-heavy oil and oil sands bitumen treatment. Product properties meet the requirements for transfer and further application.

With the rapid development of wind power in China, the installed capacity has leapt to the top of the world in a few short years, and is the fastest growing power source in addition to solar energy. However, power generation capacity and installed capacity of wind turbines in China are not in proportion to the world average; the unplanned outage coefficient of wind turbines in China is much higher than the world level. Therefore, it is urgent to carry out research on the reliability of generator sets. This study analyzes and summarizes the general conditions and problems of China's generating units, the theoretical basis of reliability evaluation of wind turbines, wind power reliability evaluation procedures, and cases, and proposes major ways to improve the reliability of wind turbines and wind farms for the majority of the Wind power industry professional and technical personnel learn from and exchange.

Integration of renewable electricity from wind farms into the electricity grid presents challenges because wind is a highly variable resource whereby the amount of power generated depends on local wind speed, air density and wind turbine characteristics. Energy storage is one possible approach to mitigate power fluctuations and quality issues. Among presently available technologies to store energy, Compressed Air Energy Storage (CAES) shows many attractive features. This work focuses on techno-economic modelling and analysis for the integration of wind turbines with CAES into the power grid. To have a deep understanding of the performance, characteristics and benefits of system integration, technical and economic models for CAES processes are developed in the processes simulation software ECLIPSE. To conduct this study, two scenarios that are each dependent on generation scales and locations were proposed; (1) centralised CAES (based on the diabatic method) (2) distributed CAES (based on the adiabatic approach). The nominal power generation of centralised and distributed CAES systems were given as 280 MWe and 5 MWe, respectively. The impact of CAES systems on the electricity market is also discussed. Techno-economic analysis of the modelled centralised CAES system showed round-trip efficiency of around 53.6% (and around 56.7% for the modelled distributed CAES system). Specific investment was found to be around €585/kWe (€2452/kWe) and break-even electricity selling price to be around €111/MWh (€275/MWh). Their CO₂ emissions were found to be compatible with the average CO₂ emissions of UK CCGT power generation.

Taking several recent successful technological transformation cases as technical reference, technical transformation plans are purposefully reviewed, pointing at questions at high temperature, for example, high back-pressure and high coal consumption for power generation. The peak cooling system distributes part of steam turbine exhaust and the air-cooling condenser thermal load reduces with the fixed cooling capacity of air cooling system. Or the capacity-increasing improves the cooling capacity with the fixed heat load of cold end system. The chosen of technical plan of direct air-cooling unit should be made on the base of its real situation.

With the national emphasis on improving the quality of atmospheric environment and protecting the ecological environment, the standards for pollutant emission from power station boilers are becoming more and more strict. In response to national environmental requirements, low nitrogen combustion technology has been adopted in coal-fired power plants. However, the introduction of low nitrogen combustion technology has also brought a series of negative effects on boiler operation. It not only includes a dramatic rise in the high ash carbon content and heating water flow, slow load response rate and such influence on the unit economy, but also includes great reduction of reheat steam temperature under low load, rapid sharp rise of load steam temperature. The steam temperature decreases when load decreasing rate greatly reduces, the effects, such as big deviation between steam temperature and wall temperature, slagging furnace, high water wall, temperature corrosion and so on, have an impact on the stability of the security unit. This paper investigates 13 coal-fired power plants with capacity of 300 MW to 600 MW in Inner Mongolia autonomous region, to study the effects of low nitrogen combustion of boiler operation, pointing out the necessity of reasonable control of the export of nitrogen oxide content.

A coordinated control method for doubly fed wind power generation system under unbalanced grid voltage is presented in this paper, which can remove the negative effects of unbalanced voltage on the doubly fed induction generator (DFIG) such as the unbalance of stator and rotor current. And the method can suppress the double frequency oscillations of the output active and reactive power. To improve the operating performance, the operation mechanism of DFIG system with a series grid side converter (SGSC) under unbalanced grid voltage is described firstly, and the strategy for series grid side converter aiming at maintaining the stator three phase voltage balance is proposed, and then the stator and rotor currents will keep balanced. Meanwhile, the mathematical model of the parallel grid side converter (PGSC) is analysed under unbalanced grid voltage and the double frequency power control equation is established. According to the control equation, a control strategy based on a proportional resonance (PR) power compensator for the parallel grid side converter is put forward, then the control goal of suppressing the double frequency oscillations of the output active and reactive power of the whole system simultaneously is accomplished, which improves the output quality of the system and ensures the safe operation of the connected grid. The proposed coordinated control strategy in this paper verified by the simulations of a doubly fed wind power generation system model built in PSCAD/EMTDC.

With the rapid development of social economy, vigorously developing solar energy has become a powerful means to solve energy and environmental problems. However, the instability of weather condition makes the output of PV power have strong randomness, fluctuations and intermittence. Thus accurate photovoltaic (PV) power forecast eliminates the negative impacts of the grid connection of PV power generation systems, which are very meaningful for effectively integrating the PV power systems into the grid. The paper presents a Simulate Anneal and Genetic Algorithm (SAGA), fuzzy c-means clustering (FCM) and least square support vector machine (LSSVM) (SAGA-FCM-LSSVM) model-based power short-term forecasting of PV power plants approach. The experimental effect of the proposed prediction method is verified by employing large datasets from the Desert Knowledge Australia Solar Center (DKASC) website. In this work, the FCM clustering algorithm is adopted to cluster the historical power datasets, and the LSSVM technique maps the multivariate meteorological factors and power data nonlinear relationship. The SAGA method is applied to improve the initial clustering centers of the FCM clustering algorithm to obtain a higher prediction performance. The prediction result of the method in this paper is contrasted with back propagation neural network (BPNN) and LSSVM models, and reveals excellent effect in improving the accuracy of prediction.

Based on the introduction of the structure of the multi-energy complementary microgrid system, aiming at the multi-objective optimization problems of the operational economy and the contact line power volatility, the corresponding objective functions and constraints are given, and the model for capacity configuration and operation scheduling optimization of the multi-energy complementary microgrid system is established. The improved particle swarm optimization method is used to solve the problem. The calculation results of the example verify the feasibility and effectiveness of the proposed optimization model and its optimization algorithm.

The interconnection of distributed photovoltaic (PV) power in the distribution network will bring plenty of adverse effects. It is critical of researching on maximum permitted capacity (MPC) of distribution network to maintain the safe operation of distribution network. A mathematical optimization model was constructed for the MPC of distributed PV with the objective of maximizing the difference between the sum of distributed PV introduction and the network loss, and the constraints of system power flow, node voltage, feeder current, and short-circuit current. At the same time, an improved Flower Pollination Algorithm (FPA) that is Flower Pollination Algorithm combined with Genetic Algorithm (GA-FPA) was proposed to analyse IEEE 33-bus system. Further, by comparing with other optimization algorithms in terms of convergence speed and convergence accuracy, like original FPA and Genetic Algorithm (GA), the correctness of the model and the effectiveness of the algorithm are verified.

With the access of distributed generations (DGs), the safe operation of distribution network has attracted much more attention. How to find out the weak nodes in distribution network is urgent to be solved. In this paper, based on complex network theory and risk theory, the improved node degree, node betweenness and node voltage over-limit risk index are proposed. Analytic hierarchy process (AHP) method isused togive index weights of node degree, node betweenness and node voltage over-limit risk. And the comprehensive index of the vulnerability of distribution network nodes is obtained by weighting. Finally, the feasibility of the index is verified on the IEEE33 nodes system. And accessing DGs to simulation, the influence of DGs on the vulnerability of distribution network is qualitatively analyzed.

As the current greenhouse effect continues to intensify, the pollution caused by the combustion of fossil fuel will continue to deteriorate, and a new type of combustion is urgently needed. This paper mainly studies the low pollutant emission characteristics of natural gas catalytic combustion furnace kiln flue gas, confirming the feasibility of heating glazed tile. Combined with the comparison of existing furnaces in kiln shapes, structural materials, fuel, burners, emissions and other aspects, we will explore the future direction of furnace development. It is pointed out that the furnace kiln technological innovation will be developed in the following aspects: small temperature difference kiln structure, light weight, low heat loss kiln wall, kiln low nitrogen burner, clean fuel.

The hydroxy amino acids have its unique effects in the biotechnology and molecular biology, and all sorts of synthetic hydroxy amino acids have also been developed. The hydroxy amino acids have been proved to be valuable for antifungal, antibacterial, antiviral and anticancer properties and known as a constituent of pharmaceutical intermediates. In addition to these fundamental researches, the hydroxy amino acids are applied widely to the synthesis of chiral drugs, such as (2S, 3R, 4S)-4-hydroxyisoleucine (4-HIL) is proved to be worthy in medical treatment, cis-4-hydroxy-L-proline (C4LHyp) and trans-4-hydroxy-L-proline (T4LHyp) are applied to build the chiral intermediates in pharmaceutical synthesis. Through comparisons chemical synthesis with biological catalysis to form hydroxy amino acids, enantioselective biocatalysts will undoubtedly be used in the synthesis of chiral pharmaceuticals. Mononuclear non-heme Fe(II)/α-ketoglutarate-dependent dioxygenases (Fe/αKGDs) that use an Fe(IV) complex intermediate to active diverse oxidative transformations with key biological roles. Studies identifying the important intermediates in catalysis and the proposed mechanisms are explained. In summary, we describe the physiological properties and synthesis regarding hydroxy amino acids, particularly 4-HIL and hydroxyproline. And the proposed catalysis mechanisms of Fe/αKGDs are also explained, while we also discussed the applications of hydroxy amino acids in fundamental research and industrial.

In this paper, the V type slit nozzle in a quick-frozen machine is used as the research object. Under the same air supply conditions, only the pressure entering the impinging jet region is changed. The impact on the flow field and heat transfer characteristics of the impinging jet is observed. The results show that with the increase of the inlet pressure, the velocity of the exit of the V-slit nozzle will change greatly. In this pressure range, the exit velocity of the nozzle is relatively uniform, and frozen products will not be blown off. Therefore, it is beneficial to frozen food safely and effectively. Along the direction of cross flow, the Nusselt number of the steel strip surface of the V slit nozzle will change when the pressure changes, and it will increase with the increase of pressure. Therefore, the heat transfer characteristics of the V type slit nozzle on the surface of the steel strip are stronger and stronger under the increase of the inlet pressure, and the uniformity is also very good.

In the economic analysis that is conducted of the electrical regulatory framework, too much emphasis is made on tariffs and laws. However, technological and organizational innovations on a large scale, such as a centre for the integration in the electrical grid of electricity coming from renewable energy sources, are fundamental. This article presents the role in the growth of renewable energies of the first large-scale centre in the world that allowed an integrated and automated management of this type of energy sources: the Spanish CECRE of the company REE (Red Eléctrica de España. S.A.). This paper studies the period between 2004-2013, when Spain became the fourth country after China, the USA and Germany in installed capacity of renewable energies and, in relative terms, the second country after Denmark.

Speed of doubly fed induction generator (DFIG) is decoupled with system frequency and system inertia is greatly reduced with increasing penetration of DFIG. It brings new challenges to system frequency security. To improve power system frequency stability, a DFIG primary frequency regulation strategy is proposed to tune droop coefficient. Taking rotational kinetic energy (RKE) into account, the droop coefficient is optimized to release both available RKE and power reserves as much as possible. The droop coefficient is optimized under different wind speeds. Comparison is made to examine the performance of the proposed method with IEEE 30 bus system.

With the wide application of distributed generations (DG) in power system, some problems appear to the power flow calculation of distribution network. In the methods of probabilistic power flow calculation based on Monte Carlo simulation (MCS), the Gibbs sampling algorithm needs a large number of complex iterative operations to get more accurate results. Aiming at the problem of the algorithm, a Markov Chain Monte Carlo (MCMC) simulation method based on slice sampling algorithm is proposed and applied to probabilistic power flow calculation of the distribution network containing distributed generation. Finally, the IEEE-33 node system is used for simulation. The results show that the slice sampling algorithm can significantly improve the computational accuracy of the traditional MCMC method. In the meantime, the slice sampling is faster and more stable than Gibbs sampling under the same number of sampling iterations.

In order to dig out more typical features of photovoltaic (PV) with multitudinous characteristic parameters, and realize fault diagnosis and classification for PV arrays effectively. A method based on principal component analysis (PCA) has been proposed in this paper. At first, the data set of PV array is processed by PCA and then a transform matrix is produced. Second, the processed data will be classified by supporting vector machine (SVM). Finally, a classification model will be built. Two sets of data, collected from PV simulation system and actual PV array, are adopted to examine this method. The result shows that the method is able to recognize four kinds of states accurately (normal, open circuit, short circuit and partial shadow). Consequently, the fault of PV array can be diagnosed and classified.

The Shanghai Electric – Siemens ultra-supercritical 660 MW steam turbine has a large proportion in the newly produced 600 MW units in China in recent years because of its superior performance index. It has become an important development direction of 600 MW level ultra-supercritical power generation technology. Taking a N660-25/600/600 steam turbine as an example, the quantitative sensitivity analysis of energy consumption of the high-pressure cylinder, intermediate-pressure cylinder and low-pressure cylinder were carried out based on the calculation method of rated power and variable condition, the influence of each cylinder efficiency change on the heat consumption rate of steam turbine is obtained. It turns out that the efficiency of high-pressure cylinder is less sensitive to energy consumption, the efficiency of intermediate-pressure cylinder is second, and the efficiency of low-pressure cylinder is more sensitive to energy consumption. The conclusion can provide technical reference for energy conservation diagnosis and energy conservation management and evaluation on this type of steam turbine.

Taking a 330 MW steam turbine after capacity expansion and efficiency improvement as the object, the problems of the cold-end system of the unit after capacity expansion and efficiency improvement are concluded. In addition, the cold-end system was improved, and the efficient arrangement of tube bundles of condenser was adopted to increase the heat exchange areas. The cooling water flow also can be increased by adopting advanced technology to improve the profile of the cooling water pump. The results show that the exhaust pressure of the turbine decreases by 1.22 kPa after the improvement of the cold-end system, compared with before. This kind of the improvement has obvious energy-saving benefits.

In this paper, the thermal performance of a 300 MW subcritical steam turbine is studied. The influence of the flow remoulding technology on the heat dissipation rate is analyzed by comparing the thermal performance test data before and after the transformation and after the completion of the operation. It focuses on the reasons for the decline in thermal performance after four-year operation. Through the transformation of the flow remoulding can greatly enhance the efficiency of the steam turbine, the gap between the steam seal and cylinder defect are the main reasons for the decrease of the thermal performance of the steam turbine after four years of operation. After four years of operation, the efficiency of the steam turbine is still superior to that before the flow.

The additional modulation function of high voltage direct current (HVDC) links can improve the system stability while the unavoidable random external disturbance and sudden changes seriously affect the controller performance and the system stability. In this paper, an improved control scheme based on inverse optimal adaptive control is proposed for the hybrid AC/DC system which considers the system parameter error, external disturbance and other random perturbation. The proposed control scheme combines the inverse optimal control approach and the adaptive control method to account for the modelling errors and uncertainty, which aims at the disturbance attenuation and the optimal operating of the hybrid AC/DC power system. Besides, the improved PI (Proportional-Integral) controller based on the lead-lag link for the current control of HVDC system is proposed to further improve system dynamic performance. Simulations conducted on a typical hybrid AC/DC system show the correctness and validity of the proposed control method.

In order to explore the mechanism of the performance of Air-cooled system influenced by environmental temperature, indirect air-cooled towers with surface condensers in power plant were studied in this paper. Through a proper simplification, the geometric models of indirect air-cooled towers and other major buildings around which may affect the fluid flow were established. When it comes to the air-cooled towers, which were located in the central region of flow and heat transfer, the structure type of the towers and the radiators should be clearly presented. Flow resistance and heat transfer characteristics of radiators were correctly and objectively taken into account, the reliability of which was verified by field test. Numerical simulation study on the thermal performance of the indirect air-cooled system with surface condensers was conducted by creating corresponding mathematical and physical models on the condition of designed wind director and velocity. At the same time, the thermal performance of indirect air-cooled towers under different environmental temperature was studied. The results showed that, the volume flow rate of air into the indirect cooling tower under different environmental temperature is basically unchanged. With temperature rising up, the density of air reduces, which leaded to a decrease on the mass flow rate of air into tower. Besides, the trends and changing laws of performance parameters from the level of segments and the tower are achieved. What's more, the flow traces of air and flue gas in towers were basically similar which were clearly divided by a temperature line, but the two flows always melt into a whole one at the export of towers. The conclusions would be of guide significance to the optimal operation and design of indirect air-cooled system.

Nowadays, price-based demand response (PDR) programs with compressed air energy storage (CAES) systems have been rapidly developed in China for wind power generation propagation. Based on this development trend, an optimal scheduling model considering thermal power units (TUs), wind power plants, PDR mechanisms and CAES plants is studied in this paper. Considering the factors of uncertainties in PDR, wind power output and electricity demand, a fuzzy power system optimal scheduling model for minimizing the sum of TUs operation cost, CAES plants cost and wind curtailment penalty is proposed. According to the fuzzy scheduling theory, the fuzzy chance constrains are converted into their clear equivalent forms. The simulation study is implemented with using the data from the Huntorf CAES plant, which can verify the feasibility and effectiveness of the optimal scheduling model. It is found that the use of CAES and PDR results in 11.1% reduction in thermal power units operation cost and 71.6% reduction in the penalty of wind curtailment.

Global development of the offshore wind energy is devoted to applying into deep water sea areas. Spar-type floating offshore wind turbine (FOWT) has been demonstrated as the most mature FOWT concept, which has been studied for the longest time by researchers among all of the FOWT concepts in the world. Due to its excellent hydrodynamic performance, spar-type FOWT is considered as the most suitable type applied in deep water and harsh sea environment conditions, which has a huge market application foreground in the future. As a consequent, investigation of the offshore wind energy requires the hydro-aero-elastic-servo simulation tools to predict the coupled complex behavior of the FOWT system. However, little validation work has been done by now in the public domain. Thus, the purpose of this paper is to validate the commonly used simulation tool, FAST (Fatigue, Aerodynamics, Structures, and Turbulence), by referring to published basin test data. Through in-depth analysis of its advantages and deficiencies, it provides a good reference for the further improvement of this floating wind turbine's numerical simulation tool in the future.

Taking an ultra-supercritical double-reheat 1000 MW steam turbine as an example, the influence rule of the ultra-high pressure cylinder, high pressure cylinder, intermediate pressure cylinder and low pressure cylinder on coal consumption of steam turbine under THA, 75%THA, 50%THA and 40%THA is analyzed. According to the data of cylinder efficiency on the heat consumption rate of steam turbine, combined with the design of the efficiency of the boiler and plant electricity rate, it is worth to work out the influence rule of cylinder efficiency on the power generation coal consumption and power supply coal consumption under THA condition. The conclusion shows that the influence of cylinder efficiency on coal consumption is basically linear. The efficiency of low pressure cylinder is the most sensitive, the efficiency of intermediate pressure cylinder is second, the efficiency of high pressure cylinder and ultra-high pressure cylinder has little effect on coal consumption. The conclusion can provide technical reference for energy-conservation diagnosis and management on the ultra-supercritical double-reheat 1000 MW steam turbine.

In the study of the heat conduction of phase change materials, due to the inherent properties, the deviation of the measured data and the processing technology of the phase change material, the uncertainty of the parameters of the material properties and geometric properties of the phase change materials exist inevitably. But at the present stage, there are very few experimental researches content of uncertain heat transfer in phase change thermal storage devices. The purpose of this paper is to study the uncertain heat transfer process of phase change heat transfer experimentally. The influence of latent heat of phase transition on the heat transfer process is mainly analyzed. The latent heat of different phase transitions is transformed into internal heat sources, and simulated by electric heating. The thermal response of phase-change heat transfer is analyzed by constructing the electric heating quantity under different probability distribution and uncertainty. The experimental results show that when the uncertainty is the same as 1/7, the difference of the standard deviation between two mean values (560 W and 630 W) is not large. The standard deviation and the mean correlation of the experimental values are not significant under the same uncertainty.

Being advantageous for long-distance power transmission and new energy connection, DC system has wide range of applications in many scenarios. As the capacity of DC power grids increases, the fault current is more difficult to interrupt. And the DC circuit breaker which is very important for protecting DC grid attracts more and more attention of researchers. In this paper, a new hybrid DC circuit breaker topology based on the technique of thyristor forced current zero is proposed. The breaker is able to interrupt the fault current in several milliseconds, and the mechanical switch can be cut off at zero current. In addition, no extra power supply and control devices are needed, the pre-charging capacitor can obtain energy from DC grid directly. Therefore, the control process is simpler and the reliability is greatly improved. The operating principle of the proposed circuit breaker is analyzed in detail, and then the simulation is carried out in PSCAD/EMTDC which verifies the correctness of the theoretical analysis and the feasibility of the breaker.

This paper presents copper loss minimization of an interior permanent magnet synchronous machine (IPMSM) drive using deadbeat direct torque and flux controller (DB-DTFC). With its constant switching frequency of DB-DTFC, the desired air-gap torque and stator flux can be achieved at the end of PWM sampling period. In this paper, a copper loss minimization DB-DTFC algorithm for an IPMSM is derived and demonstrated experimentally. Applying the presented DB-DTFC, the magnitude of stator flux linkage can be controlled while developing the commanded torque, such that copper losses of an IPMSM drive can be manipulated. The stator flux linkage that achieves minimum copper losses in an IPMSM over the given torque and speed operating space is presented. The effect of the proposed DB-DTFC algorithm is verified by analysing the efficiency maps of an IPMSM drive applying the copper loss minimizing stator flux linkage and a constant stator flux linkage.

At present, the condenser pressure of the current generation unit is generally not up to the design value during operation, which affects the thermal cycle economy of the power plant. For a subcritical 600 MW unit, for every 1 kPa reduction in condenser pressure, about 2.5g/(kW·h) reduction in power supply coal consumption. There are many problems in the operation of the original condenser of a 600 MW unit, which leads to the reduction of thermal efficiency of the unit. After the improvement of condenser tube bundle arrangement, the improvement of water chamber structure and the improvement of vacuum system, the operation effect became better obviously The performance test results of condenser after comprehensive energy-saving improvement show that the condenser pressure was reduced by 1.46 kPa under the same boundary condition compared with that before the improvement. According to the vacuum parameter correction curve of the steam turbine of the subcritical 600MW unit, the vacuum is increased by 1.46 kPa, which can reduce the heat consumption rate of the steam turbine by 94.9 kJ/(kW·h) and reduce the power supply coal consumption by 3.65 g/(kW·h).

In order to ensure that the smart grid backbone communication network architecture model has a good universality, a two-layer QoS (Quality of Service) optimization modelling method of the backbone communication networks for power protection services is proposed. Firstly, taking the communication network capacity as a constraint, the minimum value of time-QoS of the system protection service is the optimization goal, and a two-layer capacity optimization model of service quality assurance is constructed. Secondly, the optimization model is simplified and a simulation experiment is designed. The validity of the proposed method is verified by numerical examples. The simulation results of the optical layer and the electrical layer satisfy the power system protection time delay specified in the power system protocol should meet the requirement of less than 50 ms.

In the floating photovoltaic industry, the array layout, geographical location, and topographical conditions can greatly increase the difficulty to arrange the inverter-transformer in the design of a floating photovoltaic power station. Therefore, it is sometimes necessary to arrange the box-type inverter-transformer on the floating platform so that the inverter-transformer can float above the water surface. Thus the cable layout can be optimized and the economic efficiency of the project can be improved in this way. In order to ensure the stability of the inverter-transformer floating system, a specific mooring system should be designed for the floating platform. By now, the design and analysis with respect to the mooring system for inverter-transformer floating platform can rarely be conducted in the industry. In this paper, the design and analysis of the mooring system for the inverter-transformer floating platform is presented, and the related hydrodynamic calculation is performed accordingly. The design and analysis are based on the AQWA software. It can be concluded that the mooring system design presented in this paper can guarantee the stability and anti-overturning ability of the inverter-transformer floating platform. An actual engineering application of this mooring system design is finally introduced.

For the data monitoring, diagnostics and evaluation of new energy grid-connected power generation, multi-source complex data such as real-time operation data and characteristic test data are synchronized into the new energy grid-connected power generation system. And multi-source information fusion technology and online data evaluation method are used to analyze and process the data. On this basis, the establishment of a new energy grid-connected power generation remote test diagnostics system is designed. The real-time curve, test curve and fusion data curve's simulation waveform and the parameters of simulation credibility were analyzed. The experiment proves the feasibility and rationality of multi-source information fusion and online evaluation method. The system runs stably. And the test data is accurate. It provides the system platform for comprehensive grasp of the grid-connected operation characteristic and the grid-connected test diagnostics information.

The building wall is the main interface of the interior and exterior of the building and is the main channel for the exchange of heat between the interior and exterior of the building. Therefore, reducing the wall energy consumption is one of the main methods to reduce the energy consumption of the building, in the traditional building. In the energy-saving design of the envelope structure, the wall heat transfer coefficient is considered as a fixed value. The constant wall heat transfer coefficient is not conducive to the timely use of outdoor air heat dissipation or heating in buildings in areas with relatively poor daily temperatures. In order to make better use of the outdoor air and to reduce the energy consumption of buildings. This research presents a new type of wall in view of the properties that traditional building structure material's heat transfer coefficient is relatively stable, which the heat transfer coefficient changing with outdoor temperature. The characteristic of the heat transfer coefficient changing with temperature outdoor wall is the use of the natural cold/heat energy to adjust its heat transfer coefficient, at the same time it reduces indoor heating/cooling energy consumption and saves energy. This paper studies the principle and performance about regulating the heat transfer coefficient of the heat transfer coefficient changing with outdoor temperature wall and verifies the energy saving effect and automatic adjustment characteristic of the heat transfer coefficient by experimental analysis and theoretical calculation of this wall.

The structural parameters of nozzle in quick freezer have great influence on the nozzle outlet velocity, and the nozzle outlet velocity directly affects the freezing efficiency of the quick freezer. A V type slot nozzle was simulated with CFD software. The effect of the V type slot nozzle structure parameters variation on nozzle outlet velocity was studied by using Response Surface Methodology. Finally, the optimal structural parameters of the nozzle were obtained: the nozzle outlet height was 3.97 mm, the nozzle outlet width was 8 mm, the V type diversion trench height was 71.63 mm and the V type diversion trench angle was 29.57°. The conclusion provided a theoretical basis for optimal design of nozzle structure of quick freezer.

Hot-spot effect is well-known in the practical application of solar cells. The faults of hot spots seriously affect the performance and service life of solar cells. In order to highlight the infrared and visible complementary information of hot spots and discover more details, this paper presents a novel method, which fuses an infrared image saliency map based on random rectangular regions of interest with visible image by NonSubsampled Contourlet Transform (NSCT). Firstly, the infrared hot spots image was detected by saliency map which is randomly sampled. Secondly, the infrared and visible image of the hot spots are transformed into high-frequency and low-frequency sub-bands by NSCT. Finally, absolute value maximization and saliency map guidance are used to fuse low-frequency and high-frequency sub-bands respectively. The experimental results demonstrate that, compared with a set of related fusion methods, the presented method can better highlight the hot spots and other abundant information in visibility. It achieves accurate defects locating ability and has better performance on subjective and objective quality evaluation.

With the increasing dependencies on Information and Communication Technologies (ICTs), the smart distribution system has similar characteristics to Cyber-Physical System (CPS) and is seen as the so-called "cyber-physical power system" (CPPS). However, the impact of upstream substation is becoming one of the main factors impacting on distribution reliability. To avoid the too optimistic conclusion, the Cyber-Induced Dependent Failures (CDFs) of upstream substation are important to be considered. Thus the cyber security risk brought by both the malfunction of ICT components and the cyber-attack should be taken into account. This paper provided a methodology to incorporate both the two sides of CDFs in upstream substation into cyber-enabled distribution system reliability assessment. In the sequential Monte Carlo simulation (MCS), the game process between attackers and defenders can be modelled as the semi-Markov Chain (SMP), and indices are calculated by the minimal path method. The effects of CDFs are quantified and converted onto the joint feeders, based on the Breadth-First-Search (BFS), as well. Some conclusions for the distribution and substation automation planning have been made and verified by the cyber-extended Roy Billinton Test System (RBTS).

The vertical grounding electrode (VGE) is a new type of grounding design of ultra-high voltage direct current (UHVDC) power transmission project, which can greatly reduce the grounding area. The main structure of VGE is several or dozens of vertical electrode wells connected with each other by cables to form a conductor system. However, the ends of the VGE temperature may rise severely due to the non-uniform grounding current of each electrode. In serious cases, cable failures or other accidents may occur. In order to investigate the VGE temperature rise characteristics of the UHV ±800kV Pu'er Converter Station in China, firstly a single VGE was simulated in the laboratory. Measurements of the single VGE temperature rise were compared with the calculations by finite element method (FEM) to verify the validity of the algorithm. Then the calculation model was utilized to compute the current distribution of each VGE of Pu'er Converter Station, and a current balance design was proposed in this paper. Calculations demonstrated that the maximal temperature rise of the VGE was 31 °C, which was lower than the design limit. This paper may provide some useful reference for the design and operation of the UHVDC vertical ground electrodes.

Accurate fault diagnosis of photovoltaic (PV) array is important for effective operation of PV systems. The back propagation neural network (BPNN) based classifier model has wide application in fault diagnosis for PV array. Due to insufficient accuracy obtained by using single BPNN, this paper proposes a novel fault diagnosis scheme based on BP-Adaboost strong classifier. Firstly, several indicators constitute an effective feature vector which is applied to build several BPNN based weak classifier models. Secondly, Adaboost algorithm is adopted to build a strong classifier by combining those weak classifiers into the final output with certain weights. Four operation conditions including normal condition, short circuit fault, partial shade fault, open circuit fault can be accurately identified by the proposed method. Dataset from a 1.8 kW grid-connected PV system with 6 × 3 PV array are applied to experimentally test the performance of the developed method.

The paper presented two kinds of typical topology structures of hybrid-DC transmission system along with the principle of the voltage source converter for the flexible DC transmission system. After that, the paper found that the flexibility of DC voltage in the start-up process should be restricted to an extent due to the unidirectional mobility of the HVDC transmission system. Therefore, the traditional start-up control method can not be directly applied in the starting process of the hybrid-DC transmission system. To solve this problem, the paper proposed a starting control strategy based on DC line polarity switching, which is reliable for hybrid HVDC transmission. Finally, the effect of the control strategy is verified by simulation.

A V type slot nozzle in an impact type quick freezer was selected as the research object, the influence of nozzle structure parameters on nozzle outlet velocity was studied with CFD software. The results showed that the optimal height range of the V type diversion trench was 70-74mm. When the angle of V type diversion trench was 15 °, the nozzle outlet velocity reached the maximum value. As the angle increased, the outlet velocity of the nozzle increased obviously and then decreased slowly. With the increasing of nozzle width, the outlet velocity of nozzle was obviously different, and it showed the overall upward trend. The nozzle exit height had little influence on the nozzle outlet velocity, when nozzle exit height changed from 0mm to 40mm, the nozzle outlet velocity was between 13.00-14.50m/s. This study provided a theoretical basis for optimal design of impact freezer nozzle structures.

The Chinese government attaches great importance to the issue of agriculture, rural people and rural areas. After nearly twenty years, the living environment of farmers has been initially improved. However, there are still problems of uneven development and environmental pollution of some areas. For this reason, China has put forward the strategy of rural vitalization, aiming at solving the problems above. With this opportunity, it is feasible to develop green houses in rural areas. Taking the rural housing in Northeast China as an example, this paper analyses rural housing present situation there. The concept of suitability for green building technologies is raised. Based on this, the index system of suitability evaluation of green technologies for residential buildings in northeast rural areas is established. It provides strategies for the government to promote green rural housing.

In view of the trend of the development of power grid information and the characteristics and application requirements of the current new energy grid-connected characteristic test system, the cloud computing service is applied to the remote testing system. The remote testing cloud data platform for new energy grid-connected power generation is designed and constructed. On the basis of this platform, a design scheme of real-time/historical data access and wireless secure transmission is proposed. The feasibility of the high efficient storage of the platform and the reliability and security of the data transmission access are proved by the test of the remote testing system of new energy grid-connected power generation. To some extent, the platform solves the problem of data access in the existing platform. It gives full play to the role of cloud platform data center. The platform provides data support for operation characteristics analysis and grid-connected monitoring and diagnostics of new energy grid-connected generation system.

In view of the diversity, complexity and magnanimity of information data in the operation status of new energy power plant, the data mining technology is applied to fault diagnostics. On this basis, the overall process of fault diagnostics methods including clustering analysis, fault rule mining, fault modeling and other mathematical statistical theories is designed. The logical relationship between massive data is redefined at a deeper level. And the most effective fault characterization is extracted. The correctness and validity of the method are proved by comparing the curve of the fault characteristic parameter prediction results with the field measurement results. This method has high data processing efficiency, effectively improves the reliability and accuracy of fault diagnostics and early warning. And it provides a strong guarantee for the safe operation of the new energy grid-connected.

For the boiler main operation parameters, the deviation of operating parameters from the target value can cause the decrease of boiler thermal efficiency, which can further lead to the increase of unit coal consumption for power generation. Aimed at this problem, the key points of the thermal efficiency calculation for boilers mixedly burning pulverized coal and blast furnace gas (BFG) were analyzed, and the coal consumption deviation analysis model was proposed based on the modified calculation formulas. This model can provide further guidance for bolier optimized operation. A 220t/h boiler was analysed as an example, which the extra coal consumption was obtained caused by the non-optimal operation parameters.