Table of contents

Due to recent pandemic, 2022 4th International Conference on Energy Systems and Electrical Power (ICESEP 2022) was held virtually online on May 20-22, 2022. The decision to hold the virtual conference was made in compliance with many restrictions and regulations that were imposed by countries around the globe. Such restrictions were made to minimize the risk of people contracting or spreading the COVID-19 through physical contact. There were 120 individuals who attended this online conference, represented many countries.

ICESEP 2022 is to bring together innovative academics and industrial experts in the field of energy systems, electrical engineering and power engineering to a common forum. The primary goal of the conference is to promote research and developmental activities in energy engineering, electrical engineering and power engineering and another goal is to promote scientific information interchange between researchers, developers, engineers, students, and practitioners working all around the world.

During the conference, the conference model was divided into three sessions, including oral presentations, keynote speeches, and online Q&A discussion. In the first part, some scholars, whose submissions were selected as the excellent papers, were given about 5-10 minutes to perform their oral presentations one by one. Then in the second part, keynote speakers were each allocated 30-45 minutes to hold their speeches. In the second part, we invited four professors as our keynote speakers. Prof. Ismail Musirin, Universiti Teknologi MARA, Malaysia. Most of his researches dealt with the algorithms and techniques development in solving problems in Power System involving voltage stability, economic power dispatch, transient stability and so on. The second keynote speakers, Prof. Haslenda, Universiti Teknologi Malaysia, Malaysia. Prof Haslenda has an impressive list of high-quality publications (more than 200 publications to date according to Scopus) that have attracted over 5200 citations with h-index of 35. Prof. Abdul Hasib Chowdhury, Bangladesh University of Engineering and Technology, Bangladeshi. His research interests include power system planning, stability, reliability analysis, contingency and security analysis, vulnerability analysis, power quality analysis etc. Lastly, we were glad to invite Rafiziana Md.Kasmani, Universiti Teknologi Malaysia, Malaysia. Her research passions are focused on fire engineering, gas and dust explosion, and fire and explosion modelling. Their insightful speeches had triggered heated discussion in the third session of the conference. Every participant praised this conference for disseminating useful and insightful knowledge.

The proceedings are a compilation of the accepted papers and represent an interesting outcome of the conference. Topics include but are not limited to the following areas: Energy Saving Technologies, Energy Engineering and Environmental, Renewable Energy Technologies and Systems and other related topics. All the papers have been through rigorous review and process to meet the requirements of international publication standard.

We would like to acknowledge all of those who supported ICESEP 2022. The help and contribution of each individual and institution was instrumental in the success of the conference. In particular, we would like to thank the organizing committee for its valuable inputs in shaping the conference program and reviewing the submitted papers.

List of Committee member is available in this pdf.

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

• Type of peer review: Single Anonymous

• Conference submission management system: Morressier

• Number of submissions received: 173

• Number of submissions sent for review: 161

• Number of submissions accepted: 97

• Acceptance Rate (Submissions Accepted / Submissions Received × 100): 56.1

• Average number of reviews per paper: 2

• Total number of reviewers involved: 30

• Contact person for queries:

Name: Xuexia Ye

Email: xx.ye@keoaeic.org

Affiliation: AEIC Academic Exchange Information Centre

In the actual construction of an offshore wind farm, the layout of wind turbines directly affects the flow characteristics of each wind turbine. When the wind passes through the upstream unit, the work done at the hub of the downstream fan decreases, resulting in the wake effect. Therefore, on the premise of considering the wake flow, it is of great significance to study the optimization of fan arrangement. The research and selection of reasonable wind turbine arrangements have a significant effect on power generation efficiency and power output. In this paper, the improved Gauss model is used to simulate the wake flow, and the cost model that is more close to the actual construction is selected. By taking the number and distance of wind turbines as variables and the cost generated as the objective function, the research is carried out. The research is carried out in the process of automatic optimization through a particle swarm optimization algorithm.

The traditional Chinese Herbal Medicine Rhizoma et Radix Baphicacanthis Cusiae mostly grows in Southwest China. However, due to the lack of technology, the key drying process in the production of Rhizoma et Radix Baphicacanthis Cusiae has the problems of low efficiency, long time and uneven quality. The paper designed a drying system of Rhizoma et Radix Baphicacanthis Cusiae based on multi-source coupling and efficient energy storage by investigating the production of Rhizoma et Radix Baphicacanthis Cusiae in southwest China and studying the natural effects of geographical advantages and light conditions in the region. The main body of the system is composed of a two-position water tank heat circulation system, a hemispherical Fresnel lens array, an air source heat pump, a dehumidification and waste heat recovery device, a temperature and humidity sensor, and a heat exchange tube group. The drying system can better meet the drying needs of Chinese herbal medicine Rhizoma et Radix Baphicacanthis Cusiae. It has the advantages of high efficiency, energy conservation and environmental protection, stable operation, and can independently adjust according to the drying temperature. It has strong practicability. While saving energy, it saves high drying cost for farmers, and meets the special requirements of building intelligent agriculture and enriching rural economic business forms.

Due to the integration of photovoltaic power generation system, the structure of traditional distribution network will change, and then the grid system after grid connection is in an abnormal working state. If relevant measures are not taken, the operation quality of grid cannot be guaranteed. Therefore, based on the working principle of photovoltaic cells, this paper studies its equivalent model and output characteristics, builds a single-stage three-phase photovoltaic grid connected system on PSCAD platform, verifies the correctness of power control strategy, analyses the impact of photovoltaic grid connection on distribution network loss and voltage, establishes a 33 node model for example analysis, and simulates the grid connection of photovoltaic power generation system under different capacities and locations for many times, the calculation example of determining the location and capacity of photovoltaic grid connected power generation system is analysed, and a multi-objective mathematical model is proposed based on DG cost and active power loss. The installation quantity, capacity and location of DG are deeply studied, and the optimization function is carried out based on genetic algorithm, so as to realize the minimum impact condition of photovoltaic grid connected power generation on power quality of distribution network, and then realize the optimal configuration of photovoltaic power generation system.

With the development of new power system construction, distribution network as an important part, its safe and stable operation is more important. In order to make the distribution network have self-identification, self-positioning and self-healing functions, it is necessary to study the decentralized autonomous technology of the distribution network, including the state assessment and fault location technology of distributed power supply. In this paper, the autonomous intelligent agent unit (IA) is designed based on digital twin technology, which has the functions of state assessment, fault location and isolation. Through IEEE33-node with distributed power supply and MA-PSO algorithm, the internal autonomy of IA is simulated and analyzed. The results show that the proposed scheme and algorithm are fast, accurate and referable.

Flexible HVDC transmission play an important role in building a strong smart grid, and it is also very important to design a reliable redundant system for the converter valves and the valve-base controller (VBC). In order to improve the redundancy of the current valve control system, firstly, this paper proposed a new redundant configuration scheme for flexible HVDC converter valve and VBC. Secondly, this paper proposed a switching logic and switching time sequence for the redundant link, in order to make all VBC board hot-swappable when the HVDC system is in operation. Finally, depend on the "Baihetan-Jiangsu" HVDC project, the RTLAB-based test platform was established, which verified the correctness of the redundant system design. The test result shows that the designed scheme improves the redundant system reliability of the flexible HVDC system, and has well-referenced value.

In recent years, the photovoltaic power generation industry has been vigorously promoted and developed, while the solar cell as its core component may have micro-crack defects, which directly affect the power generation efficiency and stability of the photovoltaic system. Therefore, it is necessary to adopt a low-cost, efficient and flexible method to detect defects in solar cells. At present, most of the existing micro-cracks detection is carried out in the laboratory, and there is no EL micro-cracks detection in the actual photovoltaic power station. The main purpose of this paper is to design a set of EL defect detection system that can be used for actual photovoltaic power station modules, which is different from the traditional laboratory-level or module-level defect detection, and to carry the designed detection algorithm to the integrated device to operate. Experiments have shown that the system can perform real-time detection of photovoltaic module defects based on the string level, which improves the detection efficiency while saving time and cost, and shows good performance.

In this paper, a small microgrid system is composed of wind turbines, photovoltaic generators, micro gas turbines, fuel cells and battery energy storage devices. In order to realize the optimal operation of the grid-connected microgrid, a multi-objective optimal operation model with economical and environmental friendliness is established. Secondly, an adaptive strategy is introduced for the whale optimization algorithm (WOA) to improve the optimization accuracy and convergence speed of the whale algorithm. The improved whale algorithm is used to solve the target model, and the optimal operation scheme of each distributed power source in the microgrid is obtained, and the simulation analysis results are compared to verify the rationality of the improved whale algorithm.

In order to better solve the problems of current cable-overhead hybrid lines that are affected by transition resistance, fault phase angle, and fault type in fault location, this paper proposes to use the zero-sequence current method to determine the large fault section first, and then according to the electromagnetic time reversal theory (EMTR) to realize the accurate location of faults in small sectionsa. A simulation model of a cable-overhead hybrid transmission line was established using ATP-EMTP, and the program was verified in MATLAB. The simulation results show that the method is not only not affected by the transition resistance and the phase angle of the fault, but also the type of fault has no effect on the results of the distance measurement, and it has higher positioning accuracy. With the allowable relative error, different types of faults can be accurately located.

According to the demand response mode of the user side, this paper divides the flexible load into translational, reducible and transferable loads, briefly analyzes and introduces the operation characteristics of the three loads, and constructs the park comprehensive energy source system including wind power generation, photovoltaic, gas turbine and gas boiler. Considering the system investment cost, operation cost, fuel cost and compensation cost, this paper constructs the optimal allocation model of electric heating system in the park with the optimal total cost, and optimizes it through YALMIP in MATLAB. The final results show that the participation of flexible load and electric heating energy storage can not only effectively reduce the initial investment cost and total system cost in the early stage of the park, but also reasonably adjust the load curve, the optimal output point of energy storage equipment is obtained to determine the capacity of energy storage equipment.

In order to evaluate the fault location performance under the optimal configuration scheme of Power Quality Monitoring System(PQMS) monitoring points with Distributed Generation(DG) in, a fault location method based on successive binary search was proposed. Firstly, the influence of DG on traditional optimal configuration is analyzed, and the optimal configuration improvement strategy for DG access is proposed. The function relation between node voltage and fault distance under DG access is analyzed, and the ratio variation relation caused by voltage variation between monitoring points is used to reflect the characteristics of slight variation of electrical quantity, and the ranging evaluation function is established. In order to avoid the setting of convergence threshold, the disadvantage of setting fixed threshold is eliminated. Based on the mean ranging error, several feasible monitoring point configuration schemes are evaluated for ranging performance and the optimal configuration scheme for fault location performance is obtained. The 4-node system verifies that the ranging method does not need to set fixed convergence threshold. In the improved IEEE14 node system, this feature can be used to evaluate the positioning performance of four different monitoring point configuration schemes, and finally obtain the optimal positioning performance configuration scheme.

With the leap-forward development of China's economy and society, people have put forward higher demands for travel convenience. As a daily means of transportation, automobiles have gradually approached thousands of households. Therefore, the automobile industry has also developed rapidly in recent years. The construction of digital factories for automobile manufacturing and production has rapidly promoted the progress of the new energy automobile industry. The main purpose of this paper is to study the battery power estimation and remote monitoring program of electric vehicles based on the optimization algorithm. This paper mainly selects the battery model, compares and analyzes different algorithms, and completes the database design and the construction of the relevant development environment according to the functional requirements and combined with the actual situation. Experiments show that low temperature has a great influence on the discharge capacity of the battery. The battery can release 74% of the rated capacity at -5°C, while the battery can release only 56% of the rated capacity at -20°C.

The existing literature on integrated energy station-grid planning studies focuses on configuration planning. Therefore, a multi-objective hybrid particle swarm algorithm is used in this paper to solve a multi-objective optimisation model and combines a multi-indicator evaluation method based on evidence-based reasoning to select the solution with the highest evaluation value from multiple candidates (Pareto solution set) as the optimal solution. The optimal planning solution is selected from multiple candidates (Pareto solution set) by a multi-indicator evaluation method based on evidence-based reasoning, and the effectiveness of the proposed model is verified utilizing an example. The customer participation demand response optimises the demand curve by adjusting the flexible load, reduces the system operation cost and investment construction cost, and maximises the economic, environmental and reliability benefits of the integrated regional energy station grid.

The composition of precursor solutions always significantly impacts the morphology and properties of perovskite films, which plays an important role in the final performance of the solar cells. Here, PbI₂ and DMAPbI₃ were introduced in the CsPbI₃ precursor solutions. The optimized composition and structure were realized by adjusting the content ratio of the two components. The optimum content ratio of PbI₂ and DMAPbI₃ was about 3:7, which results in a uniform film with optimized internal defects. Thus, the subsequent grain formation and growth process during the annealing process are better controlled. Finally, the obtained perovskite solar cells realized a power conversion efficiency (PCE) of 16.13%.

ArcGIS software is used as the geographic information collection and analysis platform for transmission line route selection. Considering the influencing factors such as line length, landform, geology, ice area, transportation, construction, operation and local planning, the comprehensive quantitative cost value of the line is obtained by analytic hierarchy process (AHP). Combined with Ant Colony Optimization (ACO) and Python language, an automatic search model of transmission line path is developed. Selecting the local area with complex terrain in Guizhou, the algorithm simulation is carried out to verify the validity of the model. The results show that the model improves the search efficiency of transmission lines and provides a reference scheme for the planning of transmission lines in my country.

With the rapid development of modern social economy, the continuous expansion of urban land and the increasing scale of power system construction, there are many problems in cable transmission and routing in overhead transmission lines. This paper mainly introduces the tilt photogrammetry technology, and studies its application in the three-dimensional design of overhead transmission lines. Firstly, this paper introduces the concept, basic principle and key technology of tilt photogrammetry technology, expounds the importance of three-dimensional design of overhead transmission line, and then tests the error value of three-dimensional software of overhead transmission line. Finally, the test results show that the maximum plane error is 0.253 m and the mean square error is 0.168 M. The maximum error of elevation is 0.247m and the mean square error of elevation is 0.128 M. Its accuracy shall meet the requirements that the error shall not exceed 0.2m and the mean square error of elevation shall not exceed 0.2m.

Starting from an accident of overload trip and shutdown of fin stabilizer main motor caused by fin stabilizer fault, this paper studies the working principle of this type of fin stabilizer hydraulic system and electrical control system, analyzes the root cause of the fault, introduces the fault treatment method and process in detail, and puts forward suggestions on the daily maintenance and management of the equipment, so as to prevent similar accidents from happening again.

A type of gas turbine generator unit has lots of advantages, such as small size, light weight, advanced technical performance, strong environment adaptability, rapid start. However, the high temperature exhaust gas generated during the operation of the machine leads to the high temperature and obvious infrared radiation characteristics near the exhaust port. The objective of this paper is to investigate the infrared suppression of the exhaust orifice of the gas turbine generator unit. Meanwhile, some schemes about infrared suppression are proposed, that is, redesigning the exhaust cover or adding grid regenerator of high temperature phase change materials(HTPCMs). The method of computer simulation experiment, relying on Gambit and Fluent for modeling, is used to demonstrate the feasibility of the scheme. Results indicate that the first enrichment of gas turbine exhaust heat can be completed and the exhaust temperature can be reduced by about 200°C when the grid is set as a three-layer pattern crisscrossed up and down.

With the vigorous development of the photovoltaic industry, how to improve the efficiency of photovoltaic power generation has become an important issue, among which partial shadow occlusion is an important reason affecting the efficiency. The efficiency of photovoltaic power generation can be effectively improved by adopting the maximum power point tracking method (MPPT), but the traditional MPPT method is not ideal in the partial shadow occlusion of the photovoltaic array. To solve this problem, this paper proposes an improved particle swarm optimization method to effectively improve the tracking efficiency of MPPT when multiple peaks appear in the photovoltaic arrays power curve (P-V) under the partial shadow. The proposed method improves the learning factor of the traditional particle swarm optimization algorithm and designs the initial position of the particles according to the characteristics of the photovoltaic array. By adding the particle elimination mechanism, the number of particles changes dynamically, and the tracking speed of the algorithm for the maximum power of the photovoltaic array is improved. Through the result of the simulation, it is not difficult to get the conclusion that the improved particle swarm optimization algorithm can effectively improve the performance of the photovoltaic system under partial shadows.

Double-circuit lines on the same tower are more widely used due to the increasing shortage of transmission corridors. If lightning strikes cause simultaneous tripping, it will cause severe economic losses and safety problems. Transmission lines with 220 kV voltage level are an essential part of the main grid. Reducing the simultaneous tripping rate of 220 kV lines is extremely important for the safe operation of the power grid. This paper analyses the advantages and disadvantages of several typical lightning protection methods for double-circuit lines on the same tower by simulation calculation. Combined with the characteristics of several typical double-circuit towers, lightning protection design for double-circuit lines is studied, and the differentiated lightning protection methods and basic protection processes for typical lines are proposed.

In this paper, aluminum conductor steel reinforced(ACSR), high conductivity aluminum conductor steel reinforced, heat-resisting aluminum alloy conductor steel reinforced, and all aluminum alloy conductor are compared and analyzed in detail from the electrical characteristics, mechanical characteristics, and annual cost. Finally, combined with factors such as production process and construction technology, the transmission line conductor that is most suitable for a 15mm medium ice area is recommended. It provides a reference for the selection of transmission lines in future design.

The paper takes one submersible linear motor double-acting pump as a research object. A relationship of linear motor output capability and its controls parameters is concluded by building a model. The oil production system control rule is researched by optimizing voltage, frequency and other control parameters. The results showed that a way by adjusting the output voltage and frequency can improve output capability of linear motor effectively and expand the oil production depth and application range of oil production system. Changing the maximum speed of the actuator through frequency has a great influence on the change of the maximum thrust required by the linear motor, because the change of speed has a great influence on the resistance along the path. The submersible linear motor double-acting pump oil production system is more suitable for deep Wells with less oil production.

In order to avoid the influence of changes in air humidity and uneven road surface at the location where the crane operates, the operating range calculated by the crane safety operation system and the actual minimum safe distance contour surface around the transmission wire are in contact, which affects the normal and safe operation of the substation. This paper proposes and implements a self-correction method for the safety height of substation cranes based on Kalman filtering. Firstly, the method integrates multi-source information, such as air temperature and humidity, attitude Angle between crane boom and horizontal plane and vertical plane, and crane boom elongation distance, and adopts multi-classification neural network intelligent algorithm to obtain the maximum safe operating height between the crane boom end and the high-voltage cable; then, combined with the Kalman filter algorithm to filter out the error data output by the laser ranging sensor, to achieve real-time correction and optimization of the vertical distance between the crane arm and the cable. The experimental results show that when the relative air humidity exceeds 80%, the safety alarm error rate is reduced by 12.76%, which effectively improves the reliability of the safe operation of the crane safety operation system when the air humidity exceeds 80%.

At present, high voltage cables are widely used in urban transmission system. When cable fault occurs, the speed of locating fault point and the accuracy of locating fault point play a decisive factor for power system to restore power supply quickly. This article adopted the method of neural network model based on the traveling wave ranging method. It could judge the fault location of 35kV~500kV high-voltage cable more quickly and accurately. Then, we have designed a portable high volt cable fault location device, which has been tested in the domestic power plant. The experiment showed that it could quickly determine the nature and location of power cable faults, shorten the time of blackouts and reduce the loss caused by blackouts.

When a single-phase ground fault occurs near the zero or maximum point, the fault line selection of resonance grounding system is not sensitive enough. After analyzing the transient current and line impedance characteristics of zero sequence network, and making full use of the decaying DC component, power frequency component and high frequency component of the transient zero sequence current of the feeder, a fault line selection method based on correlation analysis of zero sequence current and bus zero sequence voltage derivative in high and low frequency band is proposed. The effectiveness of the method is verified by the examples from the aspects of fault closing angle, transition resistance.

Aiming at the problem that the voltage of multiple nodes exceeds the limit after the distributed photovoltaic source is connected, a reactive voltage control method of distribution network is proposed. It modeled the distribution network system with distributed photovoltaic sources, determined the maximum photovoltaic output and adjustable amount, and calculated the power flow. The line loss can be obtained from the node voltage and rated power, and the power distribution of each branch of the whole network can be further obtained. This paper analyzed the influence of photovoltaic power access on the voltage quality of the distribution network from the perspective of power. It calculated the reactive output power of reactive power compensation equipment of upstream and downstream nodes. In this paper, the active power of distributed generation is locally reduced at each out-of-limit node to control the voltage. The experimental results show that the proposed method can effectively improve the relationship between photovoltaic output and voltage, and realize the correction of photovoltaic regulation. Therefore, it can reduce the risk of voltage out of limit and improve the voltage quality.

FRP high-voltage bushing is widely used in power system because of its advantages of good mechanical strength, short production cycle and free maintenance. Due to the immobility of solid insulation such as glass fiber reinforced plastic and epoxy resin, once there is a local hidden danger, it will not heal itself, which is bound to develop into insulation breakdown. In this paper, starting from the creepage fault of a 110kV transformer FRP high-voltage bushing, comprehensive diagnosis techniques such as test detection, online monitoring, disintegration analysis and simulation calculation are adopted. Different diagnosis methods confirm each other and determine the cause of the fault. The analysis method in this paper has important reference value for fault analysis of high voltage equipment.

The construction of AC and DC transmission in China is accelerating. And the grid is getting closer, which will make the grid structure strong. However, the tightly connected power grid is more vulnerable to space weather and HVDC. Now, the researches on transformer DC bias were summarized, and the researching methods and achievements were analyzed. The main reasons and basic theory were introduced, and so did the influences to transformer. The method is generally to establish a corresponding calculation model through actual measurement, simulation and calculation, and limiting, isolating, injecting DC current are main restraining measures.

For the purpose of improving the working efficiency of lithium-ion batteries for electric vehicles (EVs), prevent battery catching fire and improve the economy of battery thermal management systems (BTMS), in this study a BTMS simulation model with direct cooling struct is built. The evaporator in the cooling circuit of the battery cells directly exchanges heat with the batteries. The performance of models using conventional R134a and environmentally friendly R1234yf was investigated without changing the model structure. The results show that: in normal temperature environment, the BTMS can effectively restrain the battery temperature from rising, the battery temperature would be suppressed under 305 K, the minimum difference of battery pack maximum temperature (T_max) and energy consumption of the BTMS using two refrigerants is 2 K and 2.3% respectively; when the working temperature is high, the BTMS can quickly drop the cells temperature below 313 K, and the shortest time difference that falling to 313K, is only 66s, and the minimum power consumption difference is 3.2%.

Through the numerical simulation of the internal flow field of the thrust bearing, the distribution of the oil membrane pressure field was calculated using the CFD software Fluent. The effect made by inclination angle and rotor speed on the thrust bearing performance was analyzed. The results show that the inclination angle has a strong impact in pumped storage units. Only when the inclination of the circular direction reaches a certain value, with the increase of the circular inclination, the bearing capacity of the oil film gradually increases, and the pressure center moves to the oil outlet. With the increase of the rotor speed, the bearing capacity of the oil film gradually increases, and the pressure center remains unchanged. Therefore, in the limit of the minimum oil film thickness, running at large inclination angles and rotor speed can improve the performance.

In order to solve the problem of effective utilization of renewable energy, energy Internet technology came into being. As the key equipment of the energy Internet, the research on energy routers is of great importance. This paper introduces the energy router from the aspects of structure and operation mode, and summarizes a general energy router structure. At the same time, the control strategies of the energy router are systematically discussed. In view of the complex and diverse control strategies of the current energy router, this paper summarizes the research status of energy router control strategies and discusses the control strategies according to different classification methods.

The access of distributed generation can cause some impacts on the distribution network, especially the change of the magnitude and direction of the short-circuit current may cause the relay protection device in the system to refuse or malfunction. Aiming at this problem, a mathematical model id founded in this paper, whose target is the maximum capacity of distributed generation. Besides normal constraints such as the node voltage and the total capacity, the current protection constraint is also taken into account. The genetic algorithm is used to optimize the capacity and location of the distributed generation in the IEEE33 bus distribution system model, and the obtained results verify the importance of taking into account the relay protection constraint.

Energy is the focus of recent years. As one of the most representative new energy sources, solar energy has the characteristics of large reserves and no pollution. The main way to use solar energy is photovoltaic (PV) power generation, and the PV module in the PV power generation system is the component that converts solar energy into electric energy. In the actual power generation process, PV modules often receive uneven solar illumination due to the shadow caused by clouds, trees, buildings, etc., resulting in changes in the output characteristics of PV modules and reduced output efficiency. Therefore, modeling of PV modules under shading condition is very important. This paper presents two simple methods for solving the parameters of PV module models, which require few parameters and are easy to obtain. A modeling method of PV modules under shading condition is also presented. And then the modeling method is verified with the experiment result. Finally, an error criterion for PV module modeling under shading condition is proposed to measure the goodness of the modeling. Combining with the two parameter solving methods, the errors of this PV module modeling method under shading condition of the error criterion proposed in this paper are 3.24% and 2.51%, respectively, which meet the requirements for engineering use.

Since the traditional contract power decomposition in the power trading market is difficult to meet the needs of new energy participating in the system operation, an optimal decomposition method of contract power based on the Q-learning algorithm under the uncertainty of new energy power is proposed. Considering the uncertainty of new energy power output, an optimization model to minimize the power purchase cost of the power grid is established. Given the uncertainty of the newly added electricity and the quotation in the market transaction, it is proposed to use the enhanced Q-learning algorithm to obtain the contract decomposition of electricity. According to the actual annual contract electricity data, the monthly optimal decomposition results of contract electricity are obtained, which verifies the economy and effectiveness of the optimal electricity decomposition method.

Electrical equipment has high vulnerability under strong earthquakes due to its own material and structure characteristics. The seismic performance of electrical equipment can be effectively improved by installing isolation devices. Based on the finite element simulation, this paper establishes the finite element simulation model of the friction pendulum isolation device suitable for the main transformer electrical equipment, calculates and compares the mechanical response of the isolation device under different design parameters. The results show that the friction pendulum isolation device with conventional design can meet the load-bearing requirements of the main transformer under conventional conditions; increasing the friction coefficient can effectively improve the energy dissipation effect of the friction pendulum isolation device, but the increase of the friction coefficient will limit the design displacement of the isolation device, and the specific isolation effect needs to be further evaluated; changing the curvature radius of sliding surface has little effect on energy dissipation of friction pendulum isolation device. The research results in this paper can provide research basis for the application of friction pendulum isolation device in the field of electrical equipment.

In recent years, due to the vigorous development of China's economy and society, the country's energy use is increasingly high, and the demand is very large. Effectively reducing power consumption while ensuring economic and social development has become a very important issue that the whole Chinese economy and society are concerned about. Based on this, a device energy consumption acquisition device is proposed in this paper. The hardware adopts ESP32 microprocessor as the core controller, and the current type current transformer is used to collect the voltage and current signal data of the device. Arduino software is used to design the acquisition program and output energy consumption data. Finally, the device is tested, and the results show that the device can collect energy consumption data of the equipment.

The transient overvoltage off-grid problem of new energy in the sending-end network has become an important factor limiting the ultra high voltage direct current (UHVDC) transmission capacity. In this paper, the causes of transient overvoltage during the DC fault process is analysed firstly, then from the perspective of adjusting the reactive power consumption of the converter, taking the Qingyu UHVDC project in China as an actual simulation example, the influence of the DC control mode and current control parameters at the rectifier side on the transient overvoltage is deeply studied. Combined with the transient voltage evaluation results of the actual power grid, guiding suggestions for DC control strategies are given to improve the transmission capacity. The research results have important reference significance for improving the consumption of new energy and the transmission capacity of UHVDC projects.

In recent years, energy storage is becoming one of the key technologies used in many countries to advance the process of carbon neutrality. Even in the face of the dual pressures of the new crown epidemic and supply chain shortages, in 2021, the global new energy storage market will still maintain a high speed growth trend. In 2021, the installed capacity of newly commissioned electric energy storage projects in the world will be 18.3GW, a year-on-year increase of 185%. Among them, the newly commissioned scale of new energy storage will be the largest, and it will exceed 10GW for the first time, reaching 10.2GW, which is the new investment in 2020. It was 2.2 times the scale of transportation, a year-on-year increase of 117%. The United States, China and Europe continue to lead the development of the global energy storage market, together accounting for 80% of the global market.

The calibration method of electronic transformer is one of the key technologies to ensure the gradual improvement of reliability and accuracy. For the phenomenon that the electronic transformer is affected by working condition, the measurement signal contains harmonics, noise and frequency fluctuation, a calibration method based on correlation and lattice notch filter is proposed. The simplified adaptive lattice notch filter is used to preprocess the collected data and extract frequency, filter out the interference of harmonics and noise, and improve the precision of the ratio error. And the interpolation correlation method which is not sensitive to noise and harmonic is used to calculate the phase difference. For the non integral period sampling caused by frequency fluctuation, the sampling data is interpolated according to the size of frequency offset. This process achieves the integral period sampling and further improve the calibration precision of angle error. Simulation results show that under the strong harmonic and noise interference the proposed method can filter out interference signals and overcome the influence of frequency fluctuation. And the results of calibrating measured data of electronic transformer show that the algorithm can fully satisfy the calibration requirements of 0.2 level electronic transformer.

MPPT intelligent control strategy algorithm is complex and practical application is difficult, So an improved sliding mode controller is proposed, which can improve engineering application, but also quickly and stably track the maximum power point of the system. In this paper, Boost circuit as the carrier, by increasing the amount of control in the controller, to build a new sliding mode control algorithm, Lyapunov stability theory analysis to demonstrate the correctness of the design algorithm, and through Simulink modeling and simulation, verify the feasibility of the control algorithm. The results show that the controller can quickly and stably track the maximum power of solar cells with small chattering and strong anti-disturbance ability regardless of the change of ambient temperature or light intensity.

The backup power supply ensures the stability and reliability of the power supply for a data center. Starting from green backup power supply, this paper studies the selection and configuration method of energy storage mode of backup power supply according to the backup power demand of data center and peak regulation demand of power grid, and analyzes different forms of green backup power supply and the output characteristics of hydrogen fuel cell. Aiming at improving the economy of green backup power assisted peak regulation, the capacity configuration principles of hydrogen energy storage and electrochemical energy storage technology are clarified, and then the capacity configuration of standby power in data center is simulated. The results show that the capacity configuration requirements of lithium battery, fuel cell and hydrogen storage tank corresponding to engineering life can be obtained through algorithm optimization.

A very weak vibration signal is generated when the pipeline leaks slightly. However, the commonly used pipeline leakage detection technology cannot obtain this kind of signal normally, thus causing large positioning error. Aiming at the above problems, a pipeline micro leakage detection technology based on Recursive Least Squares distributed optical fiber is proposed. The technology utilizes a dual Mach-Zehnder interference system with high sensitivity and simple optical path structure to monitor the interference signal caused by pipeline micro leakage at all times. Then, the adaptive filter based on Recursive Least Square method is used to denoise the interference signal. On this basis, the cross-correlation algorithm is used to obtain the delay estimation of the two test signals. This article clarifies the positioning principle of the detection technology and conducts the positioning experiment of pipeline micro leakage. The experimental results show that this technology can effectively detect the weak vibration signal generated by pipeline micro leakage and greatly improve the positioning accuracy of micro leakage points. The relative error can be controlled within 1%.

With the accelerating process of urbanization and the increasing social power consumption, power cable, as an important part of the power system, has the advantages of high power supply reliability, large transmission capacity, less land occupation and less vulnerable to the influence of the external environment. However, urbanization construction is accompanied by a large number of municipal construction, which causes great external breaking pressure on the reliable power supply of power cables. Therefore, the effective anti external breaking monitoring and early warning of power cables can reduce the losses caused by cable external breaking. This paper mainly introduces the cable anti breaking monitoring system, which captures the vibration signal to identify the signal source, such as piezoelectric sensor, sound sensor and optical fiber sensor. This paper focuses on the working principle of three distributed optical fiber anti burst systems based on OTDR (optical time domain reflection), Mach-Zender interference and Michelson interference, summarizes the characteristics and application scope of each method, analyzes the existing problems of power cable anti burst monitoring and early warning technology at the present stage, and gives the summary and prospect.

Aiming at the deformation of hydraulic turbine head cover during operation, a non-contact eddy current sensor is proposed. In this method, the turbine pit wall is taken as the static reference point, a fixed support is erected on it, and the eddy current probe is fixed at the other end of the support. Measure the gap change between the eddy current sensor probe and the head cover to calculate the absolute deformation of the head cover. The effectiveness of the proposed method is verified by taking the lifting amount test of hydraulic turbine head cover in a power plant as an example. The results show that this method has the characteristics of simple test equipment, strong adaptability and high accuracy, and can be applied to the field test of hydraulic turbine head cover deformation.

To obtain stable state within the fixed time and reduce the influence of uncertain device parameters on the buck-boost converter, this paper proposes the fixed-time sliding mode control (FSMC) and fixed-time adaptive sliding mode control (FASMC). Firstly, we build the state-space average model on the basis of the continuous conduction mode (CCM) of the buck-boost converter. Secondly, the fixed-time sliding mode surface and FSMC are studied when the device parameters are known. By analyzing the Lyapunov stability, it has been proved that the system can reach a stable state within the fixed time, besides the maximum of the fixed time is merely determined by the parameters of the control strategy. Thirdly, when the system device parameters are unknown, the FASMC is developed ensuring the system can reach the adjacent domain of the equilibrium point within the fixed time. Finally, the effectiveness of the proposed control strategies was verified by the simulation experiments.

UHV transmission lines are of great significance to the long-distance transmission of electric energy. Suspension clamp is a common hardware of line tower, and its maintenance method has large load transfer and low working efficiency. Aiming at this problem, the independent live replacement method of suspension clamp is put forward, the safety is analyzed, and the simulation analysis and test verification of the developed equipment are carried out. The results show that the research results can greatly reduce the transfer load and improve the working efficiency, which is of great significance to this type of maintenance.

The frequent occurrence of fire accidents in the charging process of electric vehicles is a relatively concerned problem. This paper has targeted analysis of electric vehicle fire causes, and the harm caused by fire. This paper puts forward the prospect and significance of battery interference protection device, analysed the working principle of battery charging interference intelligent protection device according to the types and characteristics of electric vehicle battery, and points out the important role of battery interference protection device, which has practical significance.

In recent years, intelligent electrical equipment has been widely used. Control and protection switches (CPS) have the functions of circuit breakers, relays, disconnectors and many other products, etc. The intelligent PV low-voltage switch based on fuzzy PID controller designed in this study is applicable to the low-voltage PV distribution network with rated voltage of 500V and rated current up to 1200A with direct grounding of the neutral point of three four wires. The intelligent photovoltaic low-voltage switch designed in this paper can provide indirect contact protection to the distribution network, which can reduce the occurrence of grounding accidents caused by equipment insulation damage; the intelligent photovoltaic low-voltage switch designed in this paper is equipped with a wireless transmission module, which applies the wireless communication technology to the power equipment, so that the power equipment can realize the functions of remote monitoring the operation status of the power grid and controlling the switch breaking and closing. Finally, the fuzzy PID controller is introduced to improve the reliability of switch operation.

The microgravity experiment facility with electromagnetic launch is driven and braked by a linear motor to vertically eject and recover the experimental cabin, forming a microgravity environment in the experimental cabin without external force. In order to improve efficiency and reduce power capacity, the linear motor needs segmented power supply. When the stator of linear motor is powered by sections, there are inevitable longitudinal end effect and transverse end effect, which will bring the thrust fluctuation of the motor and then affect the microgravity level of the facility. The off time of the section switch, the current and back electromotive force during off will affect the thrust fluctuation characteristics of the motor, and then affect the motion characteristics of the facility and the microgravity level. This paper focuses on the segmented power supply control method of linear motor. With real-time current acquisition, low delay power switch, current shutdown at zero crossing and other technologies, a more stable motor drive power supply is realized, the motor thrust fluctuation is reduced, the movement of the experiment cabin of the facility is more stable, and the microgravity level of the facility is improved.

In order to achieve the target damage under the number of design load cycles, an on-line damage assessment system for fatigue loading test is designed based on the interconnection mode of distributed network bus. The system uses the dynamic signal acquisition instrument to collect the blade strain data, improves the Butterworth filter for filtering and smoothing, extracts the peak and valley values of blade load by the local maximum method, establishes the relationship between section load, cycle times and material Goodman curve, and calculates the maximum action coefficient of fatigue damage based on Markov frequency matrix method and fatigue cumulative damage theory. The fatigue damage evaluation system established for the fatigue test of a 56.5m blade is experimentally studied. The test results show that the fatigue loading damage assessment system can realize data testing and real-time processing, real-time assessment of blade damage degree in fatigue loading, and has the same accuracy as the data post-processing method.

Condition-based maintenance is to select the most suitable maintenance method according to the real-time operating state of the converter. Transformer condition evaluation and fault diagnosis is an important basis for condition maintenance, and it is also the key to ensure the normal implementation of condition maintenance. The main purpose of this paper is to study the application of voiceprint feature extraction in large-scale power transformers in uninterruptible power failure diagnosis and early warning technology. In this paper, a comprehensive and in-depth study of the state quantity of transformer uninterrupted detection is carried out. Experiments show that when CR<0.10, the matrix is satisfactory and consistent, and the weight distribution is reasonable.

At present, most of the researches are based on linear systems, whose convergence speed and steady-state error are irreconcilable, and in actual operation, nonlinear factors greatly reduce the control performance of linear systems. If the nonlinear problem in the system can be solved, the active noise reduction system can choose low-cost electroacoustic devices with nonlinear distortion, which can not only improve the noise reduction performance, but also has special significance for reducing the cost of the system. Therefore, the main purpose of this paper is to study the feature identification and analysis of transformers based on sound wave interference. This paper explores the propagation, absorption and radiation process of the vibration generated by the transformer core and winding in the surrounding space, and finally obtains the vibration and noise signals of the transformer body, as well as the air sound field distribution at a specific spatial Experiments show that, compared with before the noise reduction experiment, the mean value of the noise in each main frequency band is reduced by about 7dB after the noise reduction experiment.

With the rapid development of China's national economy, the level of power system construction and operation management has been greatly improved compared with the past, but the requirements of power users for power production and management departments are also higher and higher. A lot of research work has been carried out on how to improve the power supply reliability, rapid repair ability and controllability of power system. The new type of fine reactive power compensation device introduced in this paper can better meet the above requirements, which reflects the current frontier technology direction of reactive power compensation development, and will play an increasing role in improving the voltage stability of China's distribution network, improving the power factor of equipment and enhancing the transmission capacity.

This article analyzes the cause of an abnormal defect in the oil chromatogram of a transformer, and puts forward control measures and suggestions. It is analyzed that the cause of the abnormal oil chromatogram of phase A and B of the main transformer is the poor contact o f the dynamic and static contacts of the unloaded tap changer, high temperature and overheatin g, and the development of contact ablation, resulting in abnormal oil chromatogram. The cause of the ablation of the dynamic and static contacts of the no-load tap-changer may be due to the installation and transportation (or electrodynamic shock or U-switch design and other factors), the contacts are not in close contact, the larger contact resistan ce causes the contacts to overheat, and high temperature conditions Sulfur corrosion occurs on the surface of the lower contact, and the corrosion product gradually deposits on the surface of the contact, which further aggravates the poor contact. Although passivation agent is added in t he later period, the protection effect of the passivation agent at high temperature is limited, and it can no longer protect the contact. Under the action of current, the dynamic and static contacts that cause poor contact are gradually ablated.

The microwave load water-cooling system was operated in a vacuum cold black environment, and the pressure difference between the inside and outside of the water pipe could reach 0.3 to 0.4 MPa. To ensure the tightness of the water pipe, a conical seal structure was selected, the macro-static model and micro-boundary element contact model were established for the two forms with and without the Viton seal. The macro model simulation was performed by the finite element method to obtain the stress distribution inside the conical structure under different preload stress, the relationship between the contact pressure of the conical sealing interface and the contact area of the O-ring sealing interface as a function of preload stress; the method was used to calculate the micro-contact model, and the critical contact pressure and contact area to achieve the sealing requirements were obtained respectively without Viton seal and with Viton seal. As a result, a conical seal structure with a Viton seal was finally chosen for application. After verification, the structure meets the requirements for the use of microwave load water-cooling systems during the vacuum thermal test.

This paper introduces the types, internal structures and working principles of common non-electricity protection devices, and theoretically analyzes the cooperation between non-electricity protection devices. For pressure relief devices, the requirements of relevant standards for pressure relief valves are introduced, matters needing attention in field use of pressure relief valves are summarized, and factors affecting the performance of pressure relief valves are analyzed. Finally, using the calibration platform, through a large number of experiments, the influence of external environment temperature, caliber and pressure release times on pressure release performance parameters was studied. The results show that the average opening pressure at high temperature (95°C) is significantly lower than the average opening pressure of 10 times at normal temperature. At the same time, with the increase of ambient temperature, the aging opening pressure and the average opening pressure will obviously decrease, while the average closing pressure will increase. In addition, under normal temperature environment, the test values of aging opening pressure, average opening pressure and average closing pressure have little change. For pressure relief valves with different calibers, under the same rated opening pressure, the calibers of the pressure relief valves are different, which has little influence on the actual opening pressure. Through the research on the operation reliability of qualified pressure relief valves, it is found that the opening pressure after 50 operations and the first measured opening pressure and closing pressure data after 500 operations are relatively stable.

In order to improve the regulation efficiency of the coal mine gas drainage pipe network, reduce the labor intensity of workers, and ensure the safe production of coal mines, a gas drainage pipe network regulation and control system is designed. The system adopts Siemens S7-1200 series PLC as the core control unit of the gas drainage pipe network. Through the explosion-proof treatment of the PLC control box, it meets the special requirements of PLC used in the coal mine environment. Through the design and selection of flow sensors and methane sensors it improves the flow and methane sampling accuracy of the gas drainage regulation system. By writing local control strategies and remote control strategies in PLC, the automatic regulation of the gas drainage pipeline network is realized.

In order to mine the state information of SF₆ circuit breakers (CBs) interruption chamber and evaluate the contacts state, a method of measuring and calculating the dynamic capacitance between contacts in CBs opening process was proposed. The test CB is connected in series with a high frequency AC power supply, and the voltage and current of the circuit breaker are measured during the opening process. The fundamental frequency components of the voltage and current are extracted by the short-time Fourier transform, and the dynamic capacitance curve as a function of time is calculated. The results show that due to the variation of capacitance, there are a large number of harmonics with frequencies close to the fundamental frequency in terminal voltage and current. During the first two cycles after contacts separation, the capacitance drops sharply to 33.25 pF, then with the increase of the contact distance, the capacitance decreases much more slowly and tends to be constant, and the capacitance is 20.70pF after the completion of the opening.

Shock waves generated by streamer discharge in water have huge application value to improve unconventional reservoirs. In this paper, experiment platform for high-voltage pulse discharge in water, which beneficial to research the pre-breakdown phase of subsonic streamer discharge in water of high-frequency discharge application scenarios is established. The mechanism of stream discharge and the importance of polarization process were analysed by high voltage theory. The initial time of flow column development was determined based on the time-varying characteristics, and the time of pre-breakdown phase was corrected by using the lightning shock intercept analysis theory. The results show that the polarization process should be incorporated into the pre-breakdown phase. Meanwhile, the initial development time of the flow column is the 3μs of the experimental data. After modification, the polarization process is shortened by 0.9372μs and the delay correction ratio is 24.57% after modification.

Heat transfer is one of the most common unit operations in industrial production. In this paper, the variation law of heat transfer coefficient of smooth tube heat exchanger and tube heat exchanger with spiral coil at different flow rate is discussed by experiment and numerical simulation, and the corresponding correlation formula of convective heat transfer criterion is fitted. This has certain reference significance to improve the heat transfer efficiency of heat exchanger to reduce the energy consumption of the country and improve the design of heat exchanger structure.

With the rapid development of the economy[1], the number of cars in our country continues to increase, underground parking garages have become commercial centers, supporting facilities in large residential areas, the number of underground garages is increasing, and the energy consumption of underground garage lighting systems is also rising. This question proposes an intelligent lighting control system based on the Internet of Things technology, studies the wifi protocol, wireless mesh networking technology, the Internet of Things cloud platform and other technologies. Based on the ESP32 chip, the terminal lighting control node is designed and developed, which cooperates with the sensor to realize the detection of personnel movement and light intensity information. The terminal lighting node controls the brightness and switch of the lamps according to this information, and realizes the effect of turning on the lights when the car arrives and turning off the lights when the car leaves, so as to achieve energy-saving control purpose.

Space particle radiation will greatly shorten the service life of basic components, resulting in premature failure of aircraft. For newly developed electronic components for space applications, strict anti irradiation performance evaluation must be carried out to master their working characteristics and performance degradation mechanism in space irradiation environment, so as to provide a reliable guarantee for the safe operation of aerospace electronic equipment in orbit. Taking high-voltage power devices such as SiC MOSFET and IGBT as the research object, this paper designs a high-precision weak current signal acquisition and measurement system to continuously monitor its working current under specific track applications, so as to verify the mechanism of space radiation effect and the effectiveness of reinforcement technology. The experimental results show that the system has the advantages of wide range, low noise, high precision and good stability. It can be applied to the experimental verification of high-voltage power devices in various space environments, including space station orbit.

In order to meet the needs of intelligent operation and maintenance of distribution networks, a large number of wireless sensors are deployed inside and outside the power grid for digital sensing and immediate control of the grid. However, once these wireless sensors fail, they will generate erroneous data, which affects the assessment of grid security and brings great hindrance to the automation of power system operation and maintenance. Therefore, we propose an AOA and fingerprint recognition-based sensing node location method to achieve accurate positioning of wireless sensing nodes to facilitate rapid troubleshooting. The method first enhances and denoises the signal characteristics of wireless sensing nodes to achieve pre-processing of wireless sensing fingerprint information and solve the problem of fingerprint feature recognition of data samples. After that we combine the node fingerprint information through deep learning models to achieve device type recognition of wireless sensing nodes. Finally, we design the AOA node localisation method, which uses the AOA coordinate system measurement model to perform distance measurement and coordinate conversion on the fingerprint features of wireless sensing nodes to achieve accurate and fast localisation of wireless sensing devices. The experiments prove that the method has a high accuracy rate in the identification and location of wireless sensing node devices, which can effectively improve the efficiency of grid automation operation and accurate troubleshooting.

The cogging torque is an unavoidable property of the permanent magnet motor, which will cause the motor to generate vibration and noise during the movement, and deteriorate the motor performance. In order to decrease the cogging torque of the permanent magnet synchronous motor, by analyzing the cogging torque expression, it is known that opening auxiliary slots in the rotor can decrease the cogging torque. Influence of slot pitch on cogging torque. The simulation results show that when the slot depth is 0.6mm, the slot width is 1.7mm and the slot spacing is 1.56, the cogging torque is most obvious reduced, and the cogging torque is decreased by 53.6% compared to the non-grooved state.

A single-band metasurface sample in the terahertz band is designed, simulated, and measured. This terahertz metasurface sample reveals a transmission peak. And the resonance frequency of this peak is 2.06THz (amplitude is 0.74, half-bandwidth is 0.7THz). In experiments, the diameter is reduced, which leads to the amplitude is enahcned and this peak move to low frequencies. The parameter T3 is reduced, which results in the amplitude of the transmission peak strengthened, while the resonance frequency stable. When the incident angle of the electromagnetic wave is increased, this transmission peak is reduced and the resonance frequency moved to the low frequencies. The polarization angle is increased, the metasurface sample exhibits similar resonance behaviors.

As the core equipment of urban power supply, once the cable is on fire, it will have a great impact on the economy and people's livelihood. Cable passage fire extinguishing equipment is a reliable infrastructure to eliminate cable fire, and detection components are the key to correct and timely action of fire extinguishing equipment. This paper designs a temperature detection module based on DS18B20, and discusses the design principle from the aspects of internal structure, command sequence, signal mode and so on.

In order to improve the inertia support of wind power system in case of load disturbance events, a control frequency response method based on Hammerstein-Neural Network (HNNFC) is proposed in this paper. First, the sliding mode control (SMC) law is designed according to the system frequency dynamic response equation. Then, the system is identified based -Hammerstein-Neural Network (HNN). Moreover, the system disturbance is designed of the ESO which is used as the compensator of the Hammerstein model to improve the fast and stable recovery performance of the system. Finally, the simulation results show that this method can not only release the active power through the rotor kinetic energy, but also improve the system stability recovery ability. The simulation can be seen that the proposed method can well reproduce the original control method. Compared with traditional control methods, the proposed method can improve the robustness ability of the wind power system.

Shunt active power filter (SAPF) has been widely used in active distribution network system. Improving the compensation performance of SAPF has become the focus of many scholars. The traditional filter interface usually adopts series resistance. In order to reduce the loss of damping resistance and ensure the compensation performance of SAPF, a new type of passive interface is adopted, and the double-loop control scheme of PI control combined with repeated control is adopted. By comparing the difference of the selected points of different feedback currents, when the feedback current is taken from the inverter, only a small damping resistance is needed to achieve good steady-state accuracy. Simulation results verify the correctness and effectiveness of the proposed scheme and the system feedback current selection method.

In order to design the gradient filter for indoor air purification accurately and quickly, an inverse problem design method was proposed, and the best gradient filter meeting the design requirements was developed. The filtration performance test of the gradient filter was carried out, and the test results meet the design target value. The theoretical calculation values and test values of filtration efficiency and resistance are compared and analyzed. It is found that their theoretical calculation values and test values are within the normal deviation range, which verifies the feasibility and correctness of the inverse problem solving method.

This paper investigates power allocation in cell-free massive MIMO for URLLC applications, where each access point is powered by smart grid or solar panels/wind-turbines. In particular, the closed-form achievable rate for URRLC is derived. By exploiting the derived results, a non-convex and non-smooth optimization problem is formulated for maximizing the minimum URRLC rate of all multicast group, and is NP-hard. To deal with this problem, the formulated optimization problem is transformed into a tractable version, then the classical CVX tool is adopted to solve the resultant problem. Numerical simulation verifies the practicability of the derived theoretical results and the proposed algorithm.

In order to meet the electricity requirements and improve the quality of distribution networks, it is essential to improve the reliability level of the power system. This paper established several mathematical models based on circuit analysis and computer simulation to realize the evaluation of distribution network reliability. Firstly, the Sequential Monte Carlo method was utilized to simulate the indicators of series and parallel circuits, and the Entropy Weight Method was adopted to weight the indicators. Then, simulation results were comprehensively evaluated using the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), and the evaluation model of distribution network reliability was obtained. The established mathematical model provided some guidance to construct an industrial distribution network and improve the reliability level of the power system.

Network security situation awareness (NSSA) can analyze current network status and predict trends. Intrusion detection systems are used as sources of security factor in situational awareness, and their accuracy affects the assessment of network security. The attack graph can filter out key nodes and enumerate possible attack paths, which has become the main method of risk assessment. Therefore, a network security situation assessment technology based on intrusion detection was proposed. The detection rate of the intrusion detection system was improved firstly, and then the attack graph was combined with the hidden Markov model (HMM) for network security assessment. The experimental results show that this method can effectively speculate the attack intention and reflect the results intuitively and roundly.

The grounding switch is an important component to ensure safety on its GIS and maintenance personal. In this paper, the COMSOL Multiphysics software is used to carry out electrostatic field analysis on grounding switch in GIS by the finite element method. This study also did a lot of research including drawing 3D models of key parts, gridding division and post-processing the data of electric field. The field intensity distribution diagrams and the maximum value of field intensity concentration area of key insulation position at 1100kV and 500kV are obtained. The electric field intensity distribution of GIS near the static contactor of the grounding switch is discussed, and the design of appropriately increasing the radius of the conductor in the part the great abrasion is proposed, and it provides a theoretical basis for the electric field distribution of electrical equipment.

The hydraulic system of the deep-sea miner is designed, the control model of the hydraulic system is established, the control effect of the conventional PID controller and the fuzzy PID controller on the suspension system is compared and analyzed, and the stability of the hydraulic system is simulated and analyzed.

The reliability of the distribution system includes adequacy and security. Adequacy refers to the degree to which the system capacity meets the power and energy demand of the load. Security is the evaluation of the system's ability to withstand sudden failures. In view of the uncertainty of decision factors and the difficulty to quantify the weights in the process of reliability evaluation of distribution network, an evaluation method for load restoration of a smart distribution network based on the improved relevance weight with index correlation and improved analytic hierarchy process (AHP) is proposed. The paper also proposes an evaluation system including distribution network structure level indexes. The planning scheme of the distribution network is comprehensively evaluated, and the effectiveness of the method is analyzed through the comparison of actual cases combined with the indicators of the grid structure level. Experimental analysis shows that compared with the traditional power supply reliability or system average outage time, the global index considering LRP is more refined in describing the impact of outage, and the evaluation results are more accurate.

Metal fibrous felt particulates filter has the advantages of high mechanical strength, long service life, large dust capacity, high filtration accuracy, low resistance loss and high temperature resistance. In order to obtain the influence of structural parameters of metal fibrous felt on the characteristics of steady-state filtration efficiency, the effects of structural parameters of filter material such as porosity, fiber felt thickness and fiber diameter on steady-state capture efficiency under different filtration speeds are theoretically calculated and analyzed by using numerical calculation method. The results show that the structural parameters have an important impact on the steady-state filtration efficiency, which must be controlled within a reasonable range. Reducing the surface filtration speed to less than 0.1m/s can effectively improve the filtration efficiency. This paper provides a theoretical basis for the selection of structural parameters of metal fiber felt filter material, and has important research value.

With the installation and use of large-scale photovoltaic systems around the world, the detection of photovoltaic system operation and maintenance has become increasingly important. This research uses a convolutional neural network training model to detect and classify the infrared near-field images of photovoltaic modules from small-scale photovoltaic plants in the laboratory. This model classifies the images into two categories: with and without hot spots, with a classification accuracy of 96.58%. The experimental results show that the convolutional neural network training model has a good classification result

The electric power industry is a very important fundamental industry in China's social and economic development and innovation project, which has an extremely crucial influence on the development and construction of traditional industries, construction industries and information technology fields. In order to accelerate the process of urbanization and construction of a well-off society, power-related enterprises should carry out scientific and standardized supervision and management on generation, transportation, transformation, configuration and the use of electricity, the aim is to ensure that they can comply with rule of the national standards and the needs of social development.

A high proportion of new energy equipment brings problems such as increased power source uncertainty and weaker moment of inertia to the power grid. Through large-scale grid simulation with refined models of new energy equipment, potential grid risks can be discovered and grid security can be effectively improved. The modeling accuracy of the new energy equipment model affects the simulation accuracy of the large power grid. In order to solve the accuracy problem of the new energy equipment model, a semi-physical simulation platform close to the actual equipment is used to carry out simulations of different working conditions. Based on ADPSS, a semi-physical simulation electromagnetic model of a dual-motor dual-power unit two-level direct-drive fan was built, and simulation data of different working conditions were obtained. The direct frequency control method is adopted to optimize the motor model, which reduces the steady-state fluctuation of the semi-physical simulation and improves the simulation accuracy.

It is critical for the smart grid to mining the power users' consumption behaviors. The accumulation of power data provides the possibility of conducting experiments for research focus on behavior analysis. This paper proposes a residential power users' classification method based on typical load patterns called UCM-LP, to classify users' power consumption behavior. The method firstly performs fuzzy grouping on the typical power consumption characteristics of multiple users through two-stage clustering, then divides cluster label to obtain the final power consumption categories of the user. Finally, this paper verified the algorithm using the real household power consumption data, obtaining the specific power consumption category patterns and discussed the differences among power consumption categories.

The driving module is the key component of the electronic scanning array radar system, which controls the radio frequency signal of the whole radar. It must have the characteristics of high performance, low cost, lightweight, miniaturization and easy to use. To meet this requirement, a miniaturized multi-channel Ku-band driving module design scheme is proposed in this paper. The module integrates four-channel T/R amplifier circuits, two-channel calibration switch circuits, and a RF power division network, with a total of 19 radio frequency interfaces, which can significantly reduce the number of active amplifiers in the radar system. The module adopts a positive and negative double-sided open-cavity design, combines with vertical interconnection technology to achieve more than 80dBc channel isolation of calibration switch circuit, and has good gain flatness and inter-channel phase consistency. The overall size of the module is 107mm*84mm*12mm, the weight is only 202g, the transmit power of the odd channel is greater than 26.7dBm, and the transmit power of the even channel is greater than 28.4dBm. This module can be widely used in car navigation, radar detection, and other fields due to its characteristics of small size, rich function, and easy integration.

Relay protection for AT traction networks is the key to maintaining safe and reliable operation of high-speed railways. Existing relay protection in the electrical supply network of high-speed railways often ensures its reliability at the expense of its selectivity. The current reliability-first relay protection scheme no longer meets the current safety requirements for high-speed railway operations, so the need to select a more optimised relay protection scheme is crucial. The fully parallel AT power supply method used in high-speed railways has the Feeding Section as the basic unit. Optimising the relay protection mode of the Feeding Section is of great help in optimising the AT traction network relay protection system. In this paper, the IED model for the protection of the entire Feeding Section is established by building a model based on the relevant rules of the IEC 61850 communication protocol and configuring the parameters of each logical node, starting from the actual project of the high-speed railway. The OPNET software was used to carry out simulations to prove that the IED model for line protection based on the supply arm can effectively balance the reliability and selectivity of relay protection.

Abnormalities caused by the hot spot effect are very common in the application of photovoltaic modules, which seriously affect the life and power generation efficiency of photovoltaic modules. Therefore, the study of hot spot effect is of great significance to the development of photovoltaic industry in the future. By analyzing the hot spot effect and its causes, this paper lists possible factors that may affect the hot spot effect, uses the K-proximity algorithm for hot spot detection to classify the near-field infrared images obtained in photovoltaic power plants, and designs experiments to explore the influence of several factors on the hot spot effect, the influence characteristics of the shading area and the types of shading objects are deeply explored, and finally a certain summary is made.

The current communication fault diagnosis methods mainly focus on the classifier with fault probability, which often leads to the low diagnosis efficiency. In order to overcome the above problems, mobile robot communication fault diagnosis method based on swarm intelligence algorithm is proposed in the paper. Firstly, the abnormal data is extracted after the analysis of the communication data with Kalman filter. Secondly, the supporting decision model was designed to standardize the communication exchange process and locate the fault range. Futher more, the ant colony optimization algorithm combined with particle swarm optimization was used to locate the fault area, and the multi-model hybrid method was adopted to comprehensively judge the communication fault. The different interference ratio was used in the experiment to test the performance of the proposed algorithm compared with the SVM and Bayesian model. Finally, the experiment results show the validity of mobile robort communication fault diagnosis based on swarm intelligence algorithm.

New energy including wind and solar energy has developed rapidly in the past years to lower carbon emission. Due to the high uncertainty of power generation of new energy, one challenging task is to predict the power generation so that the grid system can effectively schedule it. This paper focuses on predicting the power generation according to weather forecast. Specifically, we treat this task as a machine learning task which aims at learning a functional model that maps the weather forecast to power generation. We choose XGBoost and LightGBM as the backbone models and propose substantial techniques such as smoothing to boost the model performance. Extensive experiments validate XGBoost and LightGBM are quite suitable for this task and our proposed training techniques can indeed improve the performance.

In order to solve the problem of information extraction from Sentinel-2A satellite remote sensing images, four scene images of mountainous landscape with complex forests, flat cultivated rural landscape suburban coastal landscape and complex urban landscape were selected as experimental objects, and three algorithms of KNN, CART and SVM of object-oriented method are used to extract the main feature information, so as to compare the extraction accuracy of different methods in different scenes. The experimental results show that the overall accuracy of object-oriented feature classification of Sentinel-2A image in four scenes is greater than 75.47%, and the kappa coefficient is greater than 0.72 except that the overall accuracy of KNN in Scenes 4 is 0.66. Through the comprehensive comparative analysis of the four scenes, it can be seen that the average overall accuracy of rural landscape of Sentinel-2A image is 84.65%, the average kappa coefficient is 0.79, which is better than the average overall accuracy of urban landscape classification of 78.1%, the average kappa coefficient is 0.7, and the flat terrain scene is better than the mountainous area with large topographic elevation difference. In terms of classification methods, SVM algorithm has better classification accuracy than CART algorithm, and CART has better classification accuracy than KNN.

The watt hour metering system includes watt hour meter, voltage and current transformer, errors of them will affect the overall error of metering system. Considering harmonic, this paper studies the measurement accuracy of metering system, the harmonic equivalent circuits of energy meter, voltage and current transformer are established, their harmonic measurement errors and influencing factors are analyzed, the model of whole metering system is bulit and its measurement errors are anylyzed. Through the simulation of a specific watt hour metering system, the influence of harmonics on it is studied.

With the increasingly prominent environmental problems and the promotion of the "double carbon" goal, the participation of demand-side response resources in load peak shaving and valley filling is of great significance to the development of the power industry. In this paper, based on the background that demand-side response is being rapidly developed in China, we firstly consider the uncertainty of generating units and the operating constraints of power system and units, and construct the day-ahead output model of generating units by using stochastic production simulation and day-ahead optimal scheduling. Then, based on this model, we consider the impact of demand response on system peak shaving and build a demand response power system optimal scheduling model with unit uncertainty. Finally, the power supply and demand of the IEEE30 node system on two typical days of peak shaving considering demand response are analysed by MATLAB, and the minimum service cost of demand response and the amount of pull-out limit are derived, which clarify the important role of demand response in the process of power system peak shaving.

SF6 circuit breaker is equivalent to a capacitor between the fracture surfaces after the break port separation during the switching process. At this time, the fracture capacitance-stroke curve may be closely related to the ablation state of the contact, which is a potential life evaluation scheme. Therefore, this paper builds a typical 126kV SF6 circuit breaker arc chamber model, and calculates the capacitance curve of the separating brake. The results show that the capacitance value of the fracture is about 21 pF when the switch is off, and the capacitance value after the switch is stable is about 7 PF. The capacitance curve shows a trend of rapid decline and tends to be stable. The results can provide a basis for the subsequent use of dynamic capacitance curve to evaluate the electrical life of circuit breakers.

In this paper, the force simulation analysis of the wedge-shaped aluminum alloy wire clamp is carried out by using SOLIDWORKS Simulation software. Through the finite element modeling of the corresponding type of wedge-shaped clip, and combined with the conditions of the maximum tensile force in service state, the strength check and stiffness check, as well as the maximum stress and maximum displacement calculations are carried out. The simulation analysis result shows that the strength and stiffness of the overall structure of the wedge-shaped aluminum alloy wire clip meet the performance requirements.

To improve the reliability of the output and input power planning in interconnected regions in day-ahead dispatch scenarios, it is necessary to reasonably measure the feasible region of tie-line cross-region power exchanges. Due to the large number of day-ahead dispatch periods, it is difficult to solve the tie-line feasible region. Therefore, this paper first selects the adjacent periods to reconstruct the feasible region model and proposes a method to synthesize the feasible region of each day-ahead dispatch period. Then, the tie-line feasible regions are obtained considering the internal operation constraints of the output and input terminal regions. Finally, the final tie-line feasible region is synthesized according to the interconnection relationship of sub-regions. Based on the IEEE 39-bus system, the influence of the regional interconnection relationship on the calculation of tie-line feasible region and the evaluation results of power transmission and receiving capacity are analyzed, and the effectiveness of the method is verified.

Task allocation is an important issue in the decision-making of multi robot fire rescue in underground garage. In this paper, a multi robot and multi-objective optimization model is constructed. According to the real-time requirements of fire rescue in the underground garage scene, a two-stage multi robot task allocation algorithm based on ant colony and contract net protocol is proposed, which solves the global deficiency of the allocation result based on contract net protocol and the defect that ant colony optimization can not respond to environmental changes in real time. The comparative test results in dynamic environment show that the two-stage task allocation algorithm is similar to ant colony optimization in global cost, and its real-time performance is better than ant colony optimization.

A useful method for system frequency adjustment of wind turbines is theoretical inertia control. The classic PD theoretical inertia control has difficulty in parameter setting, and does not provide useful inertial support for the system on a case-by-case basis. Therefore, a theoretical inertia control way for wind turbines on account of Model Predictive Control (MPC) is proposed, which provides inertia support when frequency events occur. To confirm the availability of the proposed control method, MATLAB/Simulink® software was employed for system modeling and simulation. The simulation consequences demonstrate that when the system is disturbed by the load, the proposed MPC theoretical inertia control has better robustness and frequency stability than PD theoretical inertia control.