Table of contents

Due to recent pandemic, the 2021 International Conference on Energy, Power and Electrical Engineering (EPEE 2021) which was planned to be held in Jilin, China, was held virtually online during September 24-26, 2021. 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 100 individuals who attended this online conference, represented many countries including Malaysia, Australia, Ireland and China.

As a leading role in the global megatrend of scientific innovation, China has been creating a more and more open environment for scientific innovation, increasing the depth and breadth of academic cooperation, and building a community of innovation that benefits all. These endeavors have made new contribution to globalization and creating a community of shared future. EPEE 2021 aimed to promote an exchange of recent and advanced information among scientists and engineers in the wide field of "energy", "power" and "electrical engineering". The forum is also aimed particularly at promoting communication and collaboration between fundamental researchers and those engaged in the development of practical technology in respective areas of energy, power and electrical engineering.

List of Committee member is available in this pdf.

All conference organisers/editors are required to declare details about their peer review. Therefore, please provide the following information:

• Type of peer review: Double-blind

• Conference submission management system: AI Scholar System

• Number of submissions received: 186

• Number of submissions sent for review: 176

• Number of submissions accepted: 99

• Acceptance Rate (Number of Submissions Accepted/Number of Submissions Received X 100): 53.2%

• Average number of reviews per paper: 2

• Total number of reviewers involved: 50

• Any additional info on review process:

• Step 1. Each of selected paper will be reviewed by two/three professional experts in the related subject area.

• Step 2. Review Reports received from the experts will be judged by one of the editors either Review Reports are logical or not?

• Step 3. If not logical, then editor can assign new reviewer or can also judge at his/her own.

• Step 4. If logical, then Review Reports will be sent to authors to modify the manuscript accordingly.

• Step 5. Authors will be required to revise their papers according to the points raised.

• Step 6. Revised version will then be evaluated by the editor for the incorporation of the points raised by the reviewers.

• Step 7. Then the editor will send the revised manuscript to the reviewers again for re-evaluation.

• Step 8. If the reviewers approve the revise version of the manuscript, then will be accepted for publication.

• Contact person for queries:

Xuexia Ye

publication@keoaeic.org

AEIC Academic Exchange Information Centre

In the actual power system with hydropower, long-time and ultra-low frequency oscillation events occur many times. It is found that the unreasonable setting of governor parameters is an important reason for the oscillation. Firstly, the single machine on load system model is used to analyse the relationship between the PID parameters of the governor and the system stability, then the relationship between oscillation mode and PID parameters of governor is analyzed by eigenvalue analysis method, and the negative damping provided by speed regulation system is analyzed by damping torque method, and then the particle swarm optimization algorithm is used to optimize the PID parameters. Through the analysis of the step response of the single machine system before and after the optimization and the damping torque coefficient provided by the speed regulation system, it shows the effectiveness of the optimization algorithm. Finally, in the simulation platform MATLAB/SIMULINK, a single machine load system model which is closer to the actual power grid is built. The governor parameters of the generator are simulated and verified, and the PID parameters are adjusted by using the parameters obtained by the optimization algorithm. The results show that the optimized parameters have a good suppression for the ultra-low frequency oscillation.

In order to locate the disturbance source quickly and accurately in the wind farm, taking the direct drive wind turbine as an example, using the transient energy method, firstly, the transient energy flow formula is derived according to the mathematical model of each part of the direct drive wind turbine, the energy flow power is obtained by linear fitting, and the position of the disturbance source is judged by the positive and negative energy flow power; then a single machine infinite bus system model with forced oscillation source is built on PSCAD/EMTDC simulation platform for simulation. The results show that the transient energy method can accurately locate the disturbance source of direct drive wind turbine unit.

Deterioration of electric properties will be generated by the accumulation of surface charge on photovoltaic backsheet in the insulating system of photovoltaic (PV) system. The phenomena of potential induced degradation (PID) could be verified in the insulating Polyimide (PI) backsheet of PV module. In the field of photovoltaic system, PI has been found a special insulating backsheet that work in a mild condition. If the dynamic behaviors of the charge in the insulating backsheet could be understand, unexpected flashover events will be avoided. Thus, the mechanism of surface charge decay of PI should be explored under steady condition. The effect of accumulation of surface charge was explored on PI dielectric under constant ambient temperatures in this paper. The present investigation will contribute greatly toward the early potential induced degradation phenomenon of PV system.

In recent years, the photovoltaic power generation has obvious intermittent, randomness and volatility, and high permeability photovoltaic will have a huge impact on the safety and stability of the grid. The prediction of photovoltaic power generation is to improve the quality of photovoltaic grid, optimize grid scheduling, and ensure the basic technology of power grid safety and stability. In order to improve the prediction accuracy of photovoltaic power generation, this article will comprehensively carding and compare from 3 dimensions: photovoltaic power generation and meteorological factor correlation analysis, similar day selection, prediction method based on machine learning, and summarize the advantages and disadvantages of various methods. Further research has been put forward accordingly.

For grid energy storage capacity configuration is not reasonable, problems such as instability in crossing the river power fluctuations, are proposed based on a large scale wind power grid side under the condition of energy storage capacity of the optimal allocation algorithm, through the use of large-scale wind farm access method to achieve the optimal design of power grid model, so as to quickly solve the micro grid energy storage capacity planning cost and energy consumption data, according to the results. The operation parameters, energy loss and other numerical values of the model in the power grid are controlled, and according to the calculation results. Finally, the experiment proves that the optimization configuration algorithm of the power grid side energy storage capacity under the large-scale wind farm access has higher practicability and accuracy in the practical application process, and fully meets the research requirements.

In this experiment, the electro-explosive deposition energy in water of aluminum-magnesium welding wire model ER5356 at 100 kJ capacitive storage energy was investigated. The loop current and the load discharge voltage during the wire electrical explosion were measured using a self-integrating Roche coil and a capacitive voltage divider, respectively. The physical process of electrical explosion and the energy deposition process were delineated by the measured loop currents and load voltages. The current waveform and load voltage of the electric explosion in water of 1.2 mm-3.0 mm diameter Al-Mg wire at 100 kJ stored energy were measured; the changes of load resistance value, load power and deposition energy of the wire loaded with electric explosion were calculated. The results show that the peak circuit current and peak time point decrease and then increase with increasing diameter, and the minimum value is achieved at 1.6 mm wire diameter; the load voltage and load resistance values gradually decrease with increasing diameter; the load power and total deposited energy of discharge achieve the maximum value at 2.0 mm diameter. At 100 kJ energy storage, there is an optimal range between 1.6 mm and 2.4 mm wire diameter.

This paper studied two methods of using energy storage (ES) to achieve peak load shifting by charging and discharging. In different distribution network transformer power supply areas, the time of peak and valley of load is not identical. The small-scale mobile ES device was commanded to deliver energy at the peak of the power supply area to reduce the supply pressure of the power system by central control units (CCU), and while the load is at the valley, the ES charges and absorbs power to enhance the utilization rate of energy in the system. Currently, the control methods of peak load shifting for ES device (Constant Power Control and Threshold Control) were studied, and the operation results in power system were analyzed with their involvement, which provided the substantial supports for CCU to dispatch. Ultimately, the results showed the methods proposed were feasible and effective by simulation.

In order to improve the problems of serious energy waste and low utilization rate, this paper designs and builds an experimental platform for a pulsating heat pipe type phase change heat storage device. The temperature changes with time in the heat storage and release device of the barium hydroxide octahydrate phase change material under different working conditions is studied. The results show that during the heat release process, when the pulsating heat pipe is filled with water, the cooling water temperature rises to the highest, and the heat recovery rate is as high as 64%. Otherwise, the initial temperature of the cooling water during the heat release process is studied. Result shows that the initial temperature of the cooling water increases, the longer the latent heat of phase change and the total heat release time, and the higher the temperature rise of the cooling water. The experimental design of this paper can provide a reference for researchers in related fields.

The research on wide-area backup protection for high-voltage transmission lines has made certain progress in recent years, but there are few reports published on substation-area backup protection for low-voltage 10kV transmission lines. Based on the characteristics of shared information in intelligent substation, a substation-area backup protection scheme to deal with the failure of 10kV line protection device is proposed in this paper. This scheme uses the device self-test information and heartbeat mechanism to monitor the operation status of 10kV line protection devices; to realize the substation-area backup protection for the 10kV transmission lines when any line protection device fails, the protection criterion is constructed by the action results of power directional elements of transformer protections and other 10kV line protections. The proposed scheme can greatly improve the speed of the fault isolation and has low requirements for data demand and synchronization. PSCAD simulation results show that the proposed method is with high correctness and feasibility.

In this paper, the house load operation of the unit is evaluated, taking the third-generation Nuclear Power Plant (NPP) HPR1000 as an example, considering the primary loop, the secondary loop and the entire on-site electrical power systems. The main work of this study is as following: Firstly, acceptance criteria and specific numerical requirements are set out; the simulation result should meet the relevant criteria. Secondly, the Simulink simulation model of the entire system is built in detail, which can be divided into primary loop, secondary loop and on-site electrical power system parts, with emphasis on the simulation modelling of the turbine generator unit. The component models of each part and their corresponding connection relationships of each part are shown and given. Finally, a house load operation simulation is performed, and the result is compared with the acceptance criteria to verify that whether the generator has the ability to transfer to house load operation as designed.

Aiming at the hierarchical and zoning operation control of active distribution network, focusing on electrochemical energy storage, theoretical analysis and simulation research are carried out. Firstly, the basic principle of electrochemical energy storage is analyzed, and the working characteristics such as state of charge, power loss and charge discharge power are studied. Secondly, from the perspective of economic indicators, the power consumption cost of electrochemical energy storage is studied, and the objective function of global optimal dispatching of active distribution network is constructed. Then, the energy constraints and power constraints of electrochemical energy storage are studied as an important supplement to the active distribution network optimal scheduling model. Thirdly, the application of electrochemical energy storage in regional autonomous control is analyzed, and the regulation strategy of power fluctuation is studied from the perspective of standby capacity and power deviation. Finally, combined with a specific application example, the simulation analysis is given. The simulation results show that electrochemical energy storage can effectively optimize the hierarchical scheduling of active distribution network.

Under different operating conditions, the influence of energy storage battery on the power grid is different, and the location and capacity determination methods are also different. Therefore, how to scientifically and reasonably select the location is of great significance. This paper proposes a candidate set identification method for the most vulnerable branch and critical cut set of power system transient stability based on branch potential energy, and uses the improved comprehensive index to identify the critical cut set. This method does not need to wait for the end of time domain simulation to determine the most vulnerable lines and critical cut sets, thus providing the basis for the location of battery energy storage system (BESS). Through the power system comprehensive analysis program (PSASP) simulation, the accuracy of theoretical analysis and engineering practicability are verified.

In order to alleviate the peak shaving pressure of power grid and further improve the deep peak shaving capacity of coal-fired units, this paper applies staged heat storage to condensing units. Under the condition of constant boiler load, the heat of regenerative steam extraction is stored to reduce the electrical load output of the unit. Taking a 660MW ultra-supercritical unit as an example,30%THA,40%THA and 50%THA were taken as the initial conditions of heat storage respectively to discuss the peak shaving range and power regeneration efficiency of different extraction steam positions for heat storage. The results show that the "storage 1# HP heater extraction steam" scheme with "two-stage three tank" heat storage and release structure has the largest peak shaving range of 37.3%~56.9% under 50% initial conditions. When the "two-stage three tank" heat storage and release structure selects the "storage 1# HP heater extraction steam "scheme under 40% initial working condition, the "power regeneration efficiency" reaches the highest——78.3%. And the "power regeneration efficiency" of "two stage three tank" storage structure are always higher than the "single-stage" storage structure.

In order to accurately analysis the aerodynamic loads characteristics of the wind turbine under different turbulent wind conditions, the horizontal homogeneity in the flow field without a wind turbine and the numerical accuracy of the homogeneous flow field with a wind turbine were validated against the experimental results. The aerodynamic loads of the wind turbine were studied under the conditions of the uniform wind with a uniform turbulence intensity, the uniform wind with a shear turbulence intensity, the shear wind with a uniform turbulence intensity and the shear wind with a shear turbulence intensity. The results show that the increasing turbulence intensity leads to a small reduction in the torque of the wind turbine. Compared with uniform wind, shear inflow leads to a sine or cosine variation in the aerodynamic performance of the wind turbine and a reduction in the wind turbine's thrust and torque. Compared with uniform turbulence intensity, shear turbulence intensity leads to a reduction in the wind turbine's thrust and torque, and a more obvious phase lag effect, but it has little influence on the yawing moment and pitching moment.

This paper first deduces the engineering mathematical model of photovoltaic cells, then builds the photovoltaic cell and photovoltaic array model in Matlab/Simulink, and then simulates and compares the output of photovoltaic array under the condition of series and parallel connection, the number of shadows and shadow distribution. Finally, the different effects of shadow in series and parallel and the influence of shadow distribution on the output of photovoltaic array are analyzed.

Considering the correlation and nonlinear characteristics of multiple types of loads in the integrated energy system, grey relation analysis (GRA) and long short term Memory (LSTM) neural network are selected to establish the short-term load prediction model of the integrated energy system. The model uses GRA method to analyze the coupling between multiple types of loads and the meteorological factors, and then obtains the load forecast results through the LSTM prediction model. Finally, a practical example is given to verify the validity of the model.

Due to the high cost of energy storage part in traditional integrated energy systems, the demand response effect is poor. The paper proposes electrolytic water hydrogen production technology and applies it to the optimal operation of integrated energy system. By optimizing the operating cost of the system through adaptive genetic algorithm, we show that when the load matching degree was increased from 50% to 70%, the system operating cost was reduced by about 15.8%, and the carbon displacement was decreased by about 35%. System operating costs, carbon emissions, and the amount of electrolytic water systems involved in the demand response have all decreased.

Grid-tied inverters have been adopted both as the interface of renewable energy resources and as a solution to address power quality issues. To compensate the imbalance distortion caused by asymmetric local load, DQ transformation based compensation method is introduced into the control scheme of the grid-tied inverter. Taking both the inverter control scheme and circuit topology into account, the space vector based impedance modelling and stability analysis approaches are proposed in this paper to analyse the dynamic of the asymmetric system with active imbalance compensation. The proposed impedance models indicate that the compensation control method can reshape the output impedance features, and affect the stability of the system. The stability analysis results are verified in this paper by experimental results.

The opening and closing time test of 500kV high voltage circuit breaker can evaluate the mechanical characteristics and three-phase synchronization performance of the circuit breaker. Due to the influence of the earth resistance circuit, the traditional test method of circuit breaker opening and closing time can not be carried out when both ends are grounded. This paper first introduces the differential coil used to collect the signal, and then according to the requirements of field test, puts forward a test method for the opening and closing time of circuit breaker under the condition of double terminal grounding, and gives the basis for judging the opening and closing signal time. Finally, it compares and analyses the results of this method with the traditional high voltage circuit breaker opening and closing time test method, and obtains the conclusion of high voltage circuit breaker. The test method of grounding time division and closing time at both ends of the circuit breaker can fully meet the needs of field maintenance, which provides a new idea for the opening and closing time test of 500kV high voltage circuit breaker.

The condensate pipelines, main water supply pipelines, drain pipelines, and partial extraction pipelines of nuclear power plants are all coated with coatings on the outside of the pipelines to improve heat exchange efficiency. At present, the detection methods of ferromagnetic pipelines are mainly conventional ultrasound and ultrasonic guided waves. It is necessary to remove the insulation layer of the outer wall of the pipeline before the inspection, which leads to a prolonged inspection period and increased labor costs. This paper uses the measured and calculated values of the induced voltage to establish the optimal parameter inversion problem and combines the coupling relationship between the parameters to propose a reliable pulsed eddy current detection method for the relative wall thickness of ferromagnetic pipes. Using the pulsed eddy current detection method for the relative wall thickness of ferromagnetic pipelines proposed in this paper, the scanning detection of nuclear power plant steel pipes is compared with conventional ultrasonic testing. The detection results are reliable and suitable for non-destructive testing and evaluation of nuclear power plant ferromagnetic pipeline wall thickness corrosion thinning.

When a single-phase grounding fault occurs in non-solidly grounding system, the zero sequence transient current is nonlinear and non-stationary. Especially when the resonant system is grounded with high resistance, the transient quantity is weak, which brings challenges to data processing. Therefore, empirical mode decomposition (EMD) is proposed to decompose the transient quantity and obtain different intrinsic mode functions (IMF). The IMF with the largest discrimination is selected as the characteristic quantity for correlation analysis. At the same time, considering the existence of unbalanced current in the actual system, in order to avoid the influence of unbalanced current, a single-phase grounding fault line selection algorithm based on EMD decomposition and correlation analysis of zero sequence current break-variable is proposed. Finally, the effectiveness of the method is verified by simulation and field test waveforms.

The traditional power distribution station area lacks advanced functions for power distribution, and it is not conducive to operation and maintenance management. In order to improve the intelligent level of the distribution station area, it is constructed around with the intelligent distribution transformer terminal. Take intelligent distribution transformer terminal as the centre, the schemes of some typical applications, such as topology identification, line impedance analysis and three-phase unbalanced governance, are researched and designed to support the construction of distribution station area.

As the installed capacity of wind power and other renewable energy sources continues to increase, the intermittent and volatility of their output has put tremendous pressure on the safe and stable operation of the power grid. The demand for peak shaving is becoming increasingly urgent. In this paper, the electrolysis hydrogen production system participates in the deep peak shaving of coal-fired generators. Through the participation of load regulation of the electrolysis hydrogen production system, according to the requirements of the power grid on the different loads of the unit, the load of the electrolysis hydrogen production system is adjusted to adjust the load of the unit. In order to realize full-load regulation of coal-fired thermal power plants and improve the power generation efficiency of units.

In ultra high voltage(UHV) DC system, the transient characteristics for fault current monitoring of current transformers for DC application (DCCTs) and the consistency of response characteristics when different types of DCCTs are used for differential protection have become important factors affecting the safe and stable operation of DC system. In this paper, transient characteristics of all-fiber DCCTs and shunt DCCTs mainly used in DC system were studied, the main parameters of the transient characteristics including delay time and maximum peak instantaneous error were tested, and the key parameters influencing the response consistency of DCCTs were analyzed. The results show that the maximum peak instantaneous errors of all-fiber DCCTs and shunt DCCTs can meet ±5% limit requirement, meeting the demand for protection application in DC system. The delay time is the main factors affecting the maximum peak instantaneous error of DCCT. The longer the delay time is, the greater the maximum peak instantaneous error is, which may even exceed the limit value of ±5%. If necessary, the delay time of DCCTs participating in differential protection can be compensated. The research results provide a theoretical basis for preventing the malfunction of protection device caused by the inconsistent response characteristics of DCCTs in DC system.

Aiming at the problem of low accuracy of traditional methods in transmission corridor line safety monitoring, a transmission corridor line safety monitoring method based on monocular vision is designed. First of all, this article defines the target object of the safety monitoring of the transmission corridor line. Then, based on the monocular vision measurement to obtain the internal parameters of the camera geometry, optical characteristics, etc., the position of the power transmission corridor line security surveillance camera is calibrated, the power transmission corridor line security monitoring graphics are displayed, and the security monitoring data of the transmission corridor line is used for perception and track.Finally, the safety monitoring and early warning of transmission corridor lines are realized. The experimental results show that the monitoring accuracy of the design method is significantly higher than that of the control group, which can solve the problem of low accuracy of transmission corridor line safety monitoring by traditional methods.

With the rapid development of global photovoltaic applications in recent years, it is crucial to evaluate the photovoltaic generation capacity to achieve a secure and efficient utilization of photovoltaic resources. This paper proposes an available photovoltaic evaluation method for generation capacity in distribution networks. The evaluation model is based on the optimal power flow model, considering operational constraints with reactive power and voltage limits. A novel multi-segment boundary approximation method is proposed to solve the model and obtain the available photovoltaic generation capacity explicitly. In addition, the effect of hydrogen storage is explored to host the photovoltaic generation capacity of the distribution network. The accuracy and calculation speed of the proposed method is greatly improved compared with traditional methods. Furthermore, the proposed method can promote the utilization of photovoltaic generation and help dispatching, which guarantees security and improves economics in the distribution network. Simulations on the modified IEEE 33-bus system demonstrate the effectiveness of the proposed evaluation method.

The coking problem of coal-fired boiler seriously affects the economy and safety of the boiler. At the same time, the work of poking coke after coking in the boiler poses a great threat to the personal safety of poking coke personnel, which violates the purpose of establishing "intrinsic safety" in the power industry. Therefore, it is very important to analyze the factors affecting the coking of coal-fired boiler and effectively prevent the coking of coal-fired boiler. This paper studies the coking situation of High Moisture Lignite in a certain type of coal-fired boiler, calculates the characteristics of lignite, analyzes the causes of coking, and puts forward the optimization scheme of blending combustion and the research direction of burner adjustment in operation, so as to improve the coking situation in the process of operation.

The floating photovoltaic power (FPV) station becomes popular to decrease carbon emission. However, limited research has been done on the dynamic response of the mooring lines of the FPV array. Based on a typical 2.14MW FPV array, this study investigates the displacement of the array and the mooring tension of the mooring lines. The numerical model of the FPV array is built through three-dimensional potential theory with 124 mooring lines. Firstly, the effect of the environment on the response is investigated under wave-only, current-only and wind-only conditions. Then, the tension and motion in the combined environmental loads are analyzed. It is found that the wind load has the greatest influence on the motion and mooring tension on the FPV power station, the effect of wave and current on the response is very limited.

The paper firstly proposes energy storage frequency regulation for hydropower stations. Taking the actual operating hydropower station as an example, it analyzes the necessity of configuring energy storage to participate in frequency regulation for hydropower stations, and according to the hydropower station AGC regulate situation, the battery capacity of the energy storage frequency regulation system is designed, and the frequency regulation performance of the energy storage frequency regulation system at different battery capacities is analyzed. It provides reference for hydropower stations with similar needs.

A numerical model of a 5 MW semi-submersible wind turbine is established based on the reference wind turbine of American national renewable energy laboratory (NREL). The nominal diameter of the mooring chains was determined after the static wind load and wave load of the turbine under the action of typhoon being calculated by CFD method and Morison method. Finally, the dynamic responses of the turbine and the internal forces of the chains are obtained by the dynamic finite element analysis for three cases. The results show that when pretension chains are used, the turbine motion frequency is consistent with wave frequency, the surge is small, the pitch is reciprocally symmetrical, and the peak internal force of the chains is quite high. When mooring chains without pretension are adopted, the motion of the turbine consists of low-frequency drift and forced motion in sync with the wave frequency, the pitch is asymmetrical, and the internal tension force of the chains is relatively low.

Large power transformer is the main noise source of substation. With the increase of voltage grade and rated capacity, the noise radiation value of power equipment continues to increase, which has a great influence on the noise standard of substation boundary. In this paper, two test conditions of no-load voltage and load current are considered. The transformer noise testing datum is constructed. The distribution law of factory noise SPL of 220kV oil-immersed transformer is obtained. The test results provide accurate test data for transformer factory noise evaluation.

The three-dimensional model for the V and I type composite insulators used in AC 1000kV single-circuit tangent power transmission tower has been established, and conducted E-field calculation in FEM software, the results show that maximum electric field strength of corona ring used in V type insulator is about 13.9% and insulator surface 29.2% higher than that of I type, thus corona ring structure should be further optimized. So PSO algorithm has been implemented, meanwhile, submodeling technique was also used to solve such large calculation amount problem due to complexity of used model which can effectively reduce calculation amount without lose of accuracy. Then the method combining FEM and PSO algorithm has been applied to corona ring structure multi-parameter optimization used in V and I type insulators, finally, maximum E-field located in surface of ring and insulator shed can meet the electric control value, and no corona discharges can be observed when corona rings were used in actual project. The method proposed in the paper can solve structure optimization problem for large field domain and multi-media complex model, meanwhile, have reference value for researching field of insulation structure optimization with PSO algorithm.

The vibration signal generated by the transmission and impact of mechanical components of circuit breaker has chaotic performances, which is difficult to be analysed by conventional signal processing methods. The phase space reconstruction of vibration signal is worked on, and the signal reconstruction parameters are calculated by mutual information method and Cao algorithm respectively. The vibration signal is reconstructed into a high-dimensional space, and its permutation entropy is calculated as a feature vector. Support vector machine (SVM) is used to identify the failure type of circuit breaker, and PSO improved GSA hybrid algorithm is used to optimize the parameters of SVM so as to obtain high recognition accuracy. The experiment is carried out with the measured vibration signal of the typical operation state of the circuit breaker. The results show that the characteristics of circuit breaker vibration signals can be extracted accurately with the combination of phase space reconstruction and permutation entropy. By using PSO-GSA-SVM, the fault types of circuit breakers can be identified quickly and effectively, and the problems of path distortion, energy leakage and mode overlap of existing diagnosis methods can be solved.

This paper introduces a self-developed DC voltage source, which uses the Zener reference LTZ1000 as the voltage reference element. Selecting high precise resistors and using appropriate measures to insulate and isolate, the short—time relative stability of 7V output voltage provided by LTZ1000 is 1.5×10^-8. The voltage of 10V is increased up by a network, composed by high precise resistors with the same temperature coefficient, and its short—time relative stability is 2.2×10^-8. The voltage of 5V is divided by a network, composed by high precise resistors with the same temperature coefficient, and its short—time relative stability is 3.6×10^-7. The circuit is suitable for signal acquisition, voltage calibration and other applications.

Tower shadow effect and wind shear may cause power oscillation of the unit. In order to study the influence of tower shadow effect and wind shear on the output power of wind turbine, a doubly-fed turbine was taken as an example. Firstly, the influence of tower shadow effect and wind shear was considered to study the periodic power fluctuation characteristics of wind turbines. Then, according to the dynamic model of mechanical transmission mechanism, the influences of the inertia constants of generator, fan and the stiffness coefficient of the shaft system on the transient performance of the wind power generation system were considered respectively. Finally, a single machine infinite bus system model including wind speed model is built on PSCAD/EMTDC platform for simulation. The results show that the tower shadow effect and wind shear component can cause the power fluctuation of the turbine. When the power fluctuation frequency of the turbine is equal to the natural oscillation frequency of the wind turbine shafting, the resonance of the turbine occurs, and the amplitude of oscillation is the largest. Changing the transmission parameters will affect the power fluctuation amplitude and speed response speed of the unit.

In this paper, we set up a solar energy-phase change heat storage system and experimental study on the matching of the phase-change tank and three different terminal cooling equipment. Among them, phase-change water tank is used as heat source, meanwhile, radiator, heater and capillary as terminal cooling equipment. When radiator the terminal is radiator, the indoor temperature is difficult to meet the heating temperature requirements. When the terminal is heater, the indoor temperature can meet the requirements of heating temperature. However, the longitudinal distribution and lateral distribution of indoor air temperature are unevenly distributed and affect the thermal comfort of human body. When the terminal is capillary tube, the indoor temperature maintain at a high temperature and the temperature is satisfied with the thermal comfort of human body. Therefore, the capillary tube as the terminal cooling equipment is more advantageous of matching with the phase-change tank.

Radial turbine is widely used in micro-turbines, turbochargers, small jet engines and expanders, and the pursue of high system efficiency has resulted in elevated turbine inlet temperatures for some of its applications, threatening its reliability. There are, however, few cooling studies on radial turbines. This paper studies the jet impingement cooling of a turbocharger radial turbine. A small amount of air (coolant), which could come from compressor discharge cooled by an intercooler, is injected through a few jet holes on the heat shield of the turbine onto the upper part of turbine backdisc, to cool the rotor blades and the backdisc. Parameters that may affect the cooling were studied by a Conjugated Heat Transfer (CHT) numerical simulation using steady flow calculations. The influences to the cooling effects by different coolant-to-turbine mass flow ratios, Coolant-to-turbine inlet temperature ratio, number of the jets etc. were analysed by a steady flow simulation. The simulation results show that, when four jet holes are placed at blade leading edge radius, using 1.0% ~ 3.0% of the main gas mass flow of coolant, the average temperature on leading edge, inducer hub and backdisc surface is reduced by 2K ~ 17K,27K ~ 65K and 51K ~ 70K respectively. Turbine efficiency is mostly reduced little over 1% point.

At present, most units adopt the superheated steam temperature control system with cascade PID control structure. However, because most cascade PID control algorithms have no anti-integral saturation function, the automatic control of boiler superheated steam temperature cannot be put into operation normally. On the existing cascade PID superheated steam temperature regulation system, we judge the deviation value of the main regulator and the output value of the auxiliary regulator, and cancel the integration function at an appropriate time. When the input deviation signal turns over, the regulating system can immediately enter the normal regulating state, so that the cascade PID superheated steam temperature regulating system can timely and accurately regulate the superheated steam temperature. The fuel cost is saved by about 155,600 yuan per year.

Aiming at the problem of on-line centralized monitoring error of pipeline and cable environment and fresh air of air conditioning, a utility model is designed, a centralized monitoring system of pipeline and cable environment and fresh air of air conditioning is disclosed, the system structure configuration is optimized, and the system performance is improved by combining multiple central air conditioning controllers, data processors, acquisition servers and other equipment, combined with LabVIEW technology, the system software function and operation process are improved. Finally, the experiment proves that the centralized online monitoring system for pipeline and cable environment and air conditioning fresh air can better reduce the monitoring error and ensure the real-time monitoring quality of pipeline and cable environment and air conditioning fresh air.

To solve the problem that the curvature information of the large flexible rocket body affects the attitude control of the rocket body, a shape reconstruction method based on optical fiber strain sensing is proposed in this paper, which can measure the bow deformation and vibration state of the rocket in real time as the input data for adjusting the attitude control of the rocket. In this scheme, the dynamics of flexible rocket can be solved stably and quickly. In order to verify the reconstruction method, the beam model was used as the experimental analysis object, and the vibration information such as deformation of the beam model was identified through the strain value measured by fiber Bragg grating (FBG) sensors. The results show that the deformation reconstruction method can well restore the deformation and rotation angle of the beam system and has good stability and real-time performance. This method can provide a theoretical basis for the real-time deformation calculation and high-precision attitude control of future flexible launch vehicle.

In recent years, DC/AC matrix converter with higher power density have become an attractive alternative to traditional voltage source converters. The traditional PI control has been employed to achieve accurate control, but its dynamic response and stability need to be improved. In this paper, a model predictive control (MPC) with reducing power backflow is introduced in an isolated DC/AC matrix converter with a loosely coupled high-frequency transformer (LCHFT). Prediction model and optimal function model are established to improve the dynamic response of the system and reduce the power backflow.

At present, there are shortcomings in the research of micro-drive amplification mechanism, such as insufficient precision and additional force. In this paper, a kind of micro-drive amplification mechanism is designed and its positioning accuracy is simulated. Firstly, a kind of micro-drive amplification mechanism is designed, which can accurately transform the input displacement of piezoelectric ceramic actuator (PZT) into the output displacement of a certain number of amplification. the theoretical motion magnification ratio of the mechanism is 3:1. Secondly, the kinematics and simulation of the mechanism were studied, and the conversion performance of the mechanism was analyzed. The results showed that the micro-drive amplification mechanism has the advantage of high positioning accuracy (maximum positioning error is 4.67%). Finally, through strength analysis and modal analysis, the performance of micro-drive amplification mechanism is studied. This study has some reference value for the research and application of precision micro-drive amplification mechanism.

The previous experiments of overall cooling performances were most conducted using simplified models and under the similar temperature ratio of mainstream to cooling air with real gas turbine operations, and ambient outlet pressure. To discuss the reliability of this type of experimental data, this paper exhibits two series of numerical simulations. Using a real E3 blade as model, which has two-pass rib-roughened channel with inclined film holes, numerical simulations are carried out at the same temperature ratio and pressure ratio, but different fluid temperatures including mainstream and cooling air, and different outlet pressure. The numerical results reveal two important conclusions: 1) At the same outlet pressure, the overall cooling effectiveness on PS is not sensitive to the fluid temperatures, but on SS in the region between two rows of film holes, a higher fluid temperature corresponds to a higher cooling effectiveness. 2) At the same pressure ratio of inlet to outlet, the overall cooling effectiveness on PS and SS is not sensitive to the outlet pressure and fluid temperature.

With the development of global energy Internet and demand for UHV transmission, uHV transmission lines will increase rapidly and become more and more important for national economic development. The uHV transmission lines will increase year by year and become increasingly important to the economic development of the country. It is necessary to study the cleaning and detection technology of transmission line insulators that the insulators of UHVDC transmission lines such as large leakage rate, low detection efficiency and difficult cleaning of insulators. Therefore, the development of uhv transmission line insulator hot-line cleaning robot and detection integration has important engineering significance and practical value to improve the level of the operation of the uhv power transmission engineering maintenance, safe and reliable operation of the protection of uhv transmission lines. In this paper, the research on the integrated robot for live cleaning and detection of uHV transmission line insulators will greatly promote the live operation of UHV transmission lines in China. It can be directly applied to the live operation of UHV DC and can be promoted nationwide.

H₂S is an important element to high-temperature corrosion for the water-cooled wall of coal-fired boilers, thus, it is an effective means to prevent high-temperature corrosion through reducing the concentration of H₂S near the boiler wall. Since the concentration of H₂S in the boiler is closely related to the concentration of O₂ and CO, the research on the distribution of H₂S atmosphere in the boiler furnace was conducted in this paper. With the air distribution regulation as the means, local O₂ concentration is increased, to avoid the accumulation of H₂S near the wall and reduce high-temperature corrosion.

In order to meet the requirements of deep peak regulation and rapid load change, coal-fired power stations are often under low load condition. Under low load conditions, there are serious throttling loss and poor economy of GV(Governor Valve).Here, based on the DEH sequence valve control of steam turbine, we innovatively propose the two valve operation mode and write the two valve mode control logic, which can automatically switch between the sequence valve and the two valve mode according to the valve flow command. On the premise of ensuring the stable operation of the unit, the purpose of reducing the throttle loss of the turbine can be achieved during the low load and peak regulation of the unit, and the fuel cost can be saved about 970,000 yuan per year. The control method is simple, reliable and practical, and can be widely used in thermal power units involved in peak regulation.

The seed-metering device is the key component of a precision seeder. The methods to improve the seed suction and dropping efficiency of air suction drum precision seed metering device were discussed Establishing the force and equation of motion for sucking, carrying and dropping stages, the effect of the seeding parameters on the effect of sucking and seeding is analyzed. Then, the single factor and orthogonal test are carried out on the sucking pressure, the carrying pressure, the rotation rate and the dropping pressure as the experimental factors for the optimization analysis. And the optimum experimental parameters and the predicted values of each test index are obtained. That is, when the seeding pressure of -2.87kPa, the seeding pressure of -1.91kPa, the drum rotation rate of 18.72 r min^-1 and the dropping pressure of 1.74kPa, the best effect that the single rate is 93.8%.

This paper introduces the windproof and antiskid safety, types and working principles of dynamic windproof and antiskid devices in normal working conditions, analyzes the dynamic braking capacity and points out the deficiencies in the design, and puts forward relevant suggestion to provide basis for the subsequent evaluation of windproof and antiskid performance of port cranes.

A kind of substation inspection robot carrying unmanned aerial vehicle(UAV) was studied to solve the problems of complex indoor environment of substation, high intensity of manual inspection and low efficiency of traditional inspection method. Using robot mobile platform connected to the robot controller of ontology, the robot controller of ontology through wireless router and background monitoring system for information transmission and according to the background monitoring system control command control robot mobile platform preset in the transformer substation inspection lines and parking. Walking on the robot mobile platform is equipped with the UAV. Wireless information transmission between the UAV and the robot body controller, take-off and landing controlled by the robot body controller and the camera component on the UAV takes pictures of the equipment and instruments of the substation so as to complete the substation inspection work safely and reliably.

In the technology of hydraulic lifting system, it is not only necessary to ensure that the displacement and velocity accuracy of each hoist reach a certain value, but also to ensure that under the control of load balance to make each hoist smooth lift. In the conventional method, the PID control method can realize the synchronization of the function. However, the system cannot be controlled and adjusted in real time during the control parameter period, resulting in instability and uncertainty of the system. Aiming at this problem, this paper adds the fuzzy adaptive controller to carry out the master-slave control of the system. AMESim and MATLAB co-simulation were used to model the overall model of the hydraulic system. At the same time, the pressure compensator and variable throttle port model in the hydraulic reservoir were selected to build. The pressure compensator is used to keep the pressure difference of the throttle orifice constant, so as to complete the control and design of the hydraulic lifting system. Finally, the simulation results obtained not only can effectively improve the instability of the hydraulic lifting process, but also greatly improve the operation speed of the system.

The T-type three-level inverter topology has the advantages of low electromagnetic interference, high efficiency, and low output harmonic content. This article combines constant power inverter, independent control of active and reactive power output, Analyzed and studied the neutral point potential balance control of the T-type three-level inverter topology. Through PI adjustment control on the amount of charge of the capacitor, the midpoint voltage of the capacitor is always maintained in a balanced state, and the fluctuation of the midpoint voltage is controlled within ±0.23%. This method can effectively avoid the influence of the difference of capacitance parameters on the DC side on the midpoint voltage. The PLECS software simulation verifies the reliability of the capacitor voltage equalization circuit under the condition of the voltage imbalance at the midpoint of the DC side voltage source supply capacitor voltage equalization.

In real life, many models and systems are affected by random phenomena. For this reason, experts and scholars propose to describe these stochastic processes with Brownian motion respectively. In this paper we consider a kind of stochastic Vollterra dynamical systems of nonconvolution type and give some new conditions to ensure that the zero solution is asymptotically stable in mean square by means of fixed point method. The theorems of asymptotically stability in mean square with a necessary conditions are proved. Some results of related papers are improved.

Since series-compensated grid-connected system of doubly fed induction generator (DFIG) may cause sub-synchronous oscillation, with the purpose of improving the system stability, in this paper, the mechanism of sub-synchronous oscillation (SSO) is analyzed from the perspective of system damping, according to the mechanism, an additional damping controller is designed to suppress SSO. The controller uses rotor speed as the input signal and adds it into the d-axis current inner loop of the grid-side converter through filtering and proportional amplification, with the purpose of providing positive damping to the system. Finally, the model of DFIG series-compensated grid-connected system is established on PSCAD/EMTDC simulation platform to verify the suppression effect of the additional damping controller through time-domain simulation. The simulation results show that the device has good respond speed and suppression effect.

In order to effectively solve the problem of power waste caused by forgetting to cut off the power supply during standby, reduce the waste of power resources and improve the safety of electrical appliances, this paper designs an intelligent power saving socket which can be used in many scenarios. The design fully considers the cost of equipment, reliability and practicability, can greatly save electricity, so as to achieve the purpose of energy saving and emission reduction.

With the increasing installed capacity of offshore wind power, the grid-connected of offshore wind power technology based on virtual synchronous generators (VSG) control can simulate the inertia and damping characteristics of synchronous generator, which is helpful to improve the networking ability and inertial supportability of grid-connected inverter. However, VSG control also inevitably causes system oscillation, endangers the safe and stable operation of the power grid. Hence, the main circuit and control circuit of offshore wind power grid connection are firstly modeled, and the small-signal model of offshore wind power grid-connected inverter based on VSG control is obtained. Then the correctness of the model is verified by Matlab/Simulink software. Finally, the root trajectory method is used to identify the effects of VSG control parameters and line parameters on the system stability. The results show that VSG control has a significant influence on the stability of the grid-connected system, and reasonable design parameters are needed to ensure the safe and stable operation of the power grid.

In order to solve the control problem of the tip-tilt mirror under the unknown disturbance, a nonlinear disturbance observer with adaptive ability based on the sliding mode control is designed.Firstly, the sliding mode control method of the tip-tilt mirror system is established with Lyapunov functions. Secondly, an adaptive nonlinear disturbance observer is developed on a basis of observer model. Finally, the proposed sliding mode control method is combined with a nonlinear observer with adaptive capability to achieve the goal of improving the control accuracy of the system, while also reducing the chattering caused by the system. The experiment proves that this method is achievable. The experimental results show that the tracking error of the azimuth axis is reduced from 1.637μrad to 1.083μrad, and the accuracy is improved by about 51.2%. The tracking error of the pitch axis is reduced from 1.966μrad to 1.614μrad, and the accuracy is improved by about 21.8%. This method can greatly weaken the inherent chattering and external disturbance of the system, and improve the stability of the tip-tilt mirror system.

In order to solve the heating problem of electronic devices, an optimal configuration of rectangular cavity straight fin phase change material (PCM) based heat sink is determined to extend the safe operating time in the charging process. With PCM-based heat sink as the object of research, a three-dimensional and transient melting model is constructed. The effects of fin number, height and thickness on phase change heat transfer process and natural convection are explored in depth, and the optimal configuration parameters of PCM-based heat sink are obtained. The results show that the configuration of 8 fins,15 mm in height and 2 mm in thickness is adopted as the optimal heat sink structure, with the longest safe operating time-1170 seconds. In the stable period of phase transition, the base temperature remains unchanged and the natural convection disturbance is strong. The short and dense fin arrangement can prolong the safe operating time of safety limit temperature 343K better.

Heating load is affected by many uncertain factors, which makes it show certain randomness. To further improve the heating load forecasting accuracy, reduce the prediction error, using cross validation (CV) ideology in the choice of a model of performance evaluation and the superiority, combined with the advantages of particle swarm optimization (PSO), which is easy to implement and has stronger global optimization ability, the important parameters (penalty factor C and RBF kernel function parameter γ) are optimized, and the best parameters are automatically found in the training set, so as to obtain the best training model. Compared with other algorithms, the model precision of this method is improved a lot, and the prediction result is more accurate.

Commissioned for wind power system there are two main types of generators, one is doubly fed induction generator(DFIG), the other is permanent magnetic synchronous generator(PMSG). Compared to DFIG unit, PMSG wind power system is more economical for manufacturing and maintenance. With the higher penetration rate of wind power generation in the grid, the need for the renewable power units to provide active frequency support yields relevant control characteristics in their power converters, for which the visual synchronous generator control exhibits promising features. This paper proposes a visual synchronous technology based PMSG wind power system. The simulation results verified the effectiveness of this proposed controller.

With the wide application of switching power supply, the research on its control method has become a hot spot at present, and DC-DC converter is one of the switching power supplies with the highest frequency. However, in daily use, the input voltage of the converter may fluctuate greatly, so it is very important to obtain a stable DC output voltage. Therefore, this paper proposes a nonlinear composite control strategy method based on T-S fuzzy sliding mode control for the system disturbance problem of DC-DC converter. After establishing the T-S fuzzy model, the variable structure control theory is added, and the sliding mode surface and sliding mode control law are designed and their stability is proved by Lyapunov function. The simulation results show that the proposed control method has a good control effect and can keep the system robust.

How to use the amplitude-frequency characteristics to reconstruct the signal to obtain the time-domain response has always been a concern in the field of nuclear electromagnetic protection. So far, in practical applications, parametric modeling and non-parametric modeling have been used to solve related problems. This article summarizes the research and development of using amplitude-frequency characteristics to recover time-domain signals in the field of nuclear electromagnetic pulse protection, and briefly introduces the shortcomings of the two methods in combination with specific experiments.

With the sudden outbreak and rapid spread of COVID-19, global economic development and social stability have been seriously affected. The virus mainly spreads infection among people on a large scale through the air. People are gradually focusing on how to use HVAC system, so that it can play a more efficient and positive role in epidemic prevention and control. Consequently, we designed an intelligent purification and disinfection apparatus for air-conditioning units. The apparatus integrates rapid virus detection and high-efficiency disinfection functions. It uses a modular design and different operating modes for different levels of epidemic periods. This apparatus is not only suitable for daily life, but also can meet the prevention and control requirements during the epidemic period, which takes the economy, energy saving, and environmental protection into account.

Airborne Wind Energy (AWE) mainly collects wind energy by tethered aircraft at a certain altitude. This paper discusses the recent development of AWE. The actuator disc theory is adopted to consider the influence of kites on wind flow obstruction. The difference of working mode between a horizontal-axis wind turbine (HAWT) and a crosswind kite power systems (CKPS) is compared, the power limit of HAWT and CKPS is calculated, and the reason of the limit power is analyzed. It is pointed out that CKPS has a wider range of flight and should be further analyzed and calculated rather than simply generalized by the system disk theory.

Taking the air conditioner cluster as the object, under the condition of individual perception and controllable state of the air conditioner, the cluster state is given a considerable and controllable function. In the analysis of the load model of a single air conditioner, considering the comfort of indoor temperature, the characteristics of on and off are given, that is, the cycle of on time and off time; on this basis, the air conditioning clusters are divided according to the same or similar switching cycles, thereby forming a switching strategy of series and parallel groups to achieve load balance. In the on state, if the adjustment of the power of the air conditioner itself is not considered, a simple aggregation control method is given. The analysis of numerical examples shows that this method is simple and reliable.

This paper first applies a chaotic system-Duffing oscillator to a metal detector, and uses RHR algorithm to compute two Lyapunov characteristics exponents of the Duffing system. In this way, the two Lyapunov characteristic exponents can help to judge the Duffing system being chaotic or not quantitatively. And also help to get the threshold value more accurately. Then a simulation model of Duffing system fit for detectors is established by Matlab. Simulation results indicate that an suitable Duffing system can improve the sensitivity of a detector effectively.

The mechanism of partial discharge(PD) is the theoretical basis of the PD detection, insulation monitoring and risk assessment. The finite element analysis of partial discharge is an effective measure to study the characteristics of PD. In this work, a physical model of PD of a gas gap in solid dielectric using finite element analysis (FEA) method has been developed to determine the relationship between the inception electric field with different applied stresses, the cavity diameter and air pressure has been considered as the physical parameters that affect PD characteristics. The change of potential distribution before and after the discharge and the field strength during the discharge are analyzed.

In this study, the full range of load rejection performance of HPR1000 NPP is evaluated against the UK Grid Code considering the primary loop, the secondary loop, and the electrical system. The main work of this paper includes three parts. Firstly, the UK grid operational requirements are introduced including frequency requirements, voltage requirements, power requirements, etc. The criteria and specific numerical requirements to be followed in the simulated steady-state and transient states are listed, and the simulation results should meet the grid operation requirements; Secondly, the Simulink simulation model of the whole system is built in detail, and the simulation model can be divided into NSSS, turbine generator, and electrical power system sections. The component modules of each part and their corresponding connection relationships of each part are shown and presented; Finally, a load rejection simulation is performed to demonstrate that the unit has the ability to regulate its active power output and frequency as required in the Grid Code.

At present, when model parameter identification is carried out, measurement data from phase measurement units or fault recorders are generally used directly. These two types of devices can directly provide the fundamental positive sequence quantities required for parameter identification, but cannot output the dq components. If these measurement data can be fully utilized for parameter identification, it is very beneficial to improve the model accuracy. In this paper, according to the engineering needs of load model parameter identification, the extraction method and variation law of dq components are studied, and the data pre-processing tool is developed and put into use.

Currently, virtual power plants (VPP) in urban areas face problems such as over-dispersion of distributed power sources, insufficient source-load coordination. Traditional VPP planning method increases the difficulty in the operation and the dispatch of VPP. Therefore, this paper proposes a planning method for urban VPP that fully considers the coupling characteristics between the buses. From the distribution network to district to bus, a multi-objective bilevel optimization planning model for urban VPP is established. The upper-level planning model aims at minimizing the annual comprehensive cost, and derive the overall capacity of wind power turbine (WT), photovoltaic(PV), and energy storage system (ESS) of VPP in each district. The lower-level planning model aims at minimizing the network loss, and realizes the site selection and capacity allocation in each selected site. The case study based on the IEEE-33 standard system was carried out to verify the advancement and effectiveness of the proposed method.

In order to improve the practical effect of the fault location technology, it is necessary to analyze the error caused by the three-phase asynchronization of the fault indicator recording. The influence of the three-phase recording asynchronization on the fault location of the distribution network is analyzed from the aspects of the start-up criterion, the error level of the zero-sequence current and the zero-sequence voltage. The simulation results show that fault location devices of different principles are affected differently by the asynchronization recording. In order to avoid mistake start-up of the fault location device, the change value should be used to construct the fault location start-up criterion. Meanwhile, the measurement accuracy of transient fault characteristics will be affected to a certain extent by the asynchronization of the fault indicator recording, but it has little effect on the reliability of fault location, and it can even make the fault characteristics more obvious after the single- phase fault occurs.

This study focuses on the fault ride through capability of HPR1000 NPP in the UK grid and presents a Simulink-based modelling and simulation of the demonstration. The paper firstly introduces the fault ride through requirements of the UK grid, then describes the modelling process and analyses the simplified part accordingly, and finally analyses a three-phase ground fault with a duration of 140ms and a three-phase ground fault with a residual voltage of 85% and a duration of 180 seconds. The results show that the fluctuations of the plant under various fault ride through scenarios meet the requirements of the UK grid indicating the plant has fault ride through capability in the UK grid.

Steel formwork is used for concrete casting and forming, and plays a key role in the construction of high-rise buildings with asymmetrical large loads. In order to make the inner and outer formwork can be lifted synchronously, the difficult problem of unbalanced inner and outer formwork must also be overcome. According to the synchronization principle of the hydraulic lifting system and the performance parameters of its main components, AMESim model was created and the simulation was done for two hydraulic cylinders bearing the same heavy load and different weight load respectively. Therefore, the synchronization scheme of shunt valve is proposed.

With the strengthening of the integrated characteristics of power grid and the construction of the New Generation Dispatching and Control System with "physical distribution, logical integration", the demand for global monitoring and analysis of power grid has gradually increased. On the basis of understanding of design of the new generation real-time dispatching and control data platform system, with the principles of componentization and servitization, the real-time power grid WebGIS visualization framework is designed and implemented. And this paper further introduces the design of the front-end secondary development interface and examples, as well as the cartographic generalization of the power grid WebGIS visual map. This framework has successfully supported the construction and online operation of several real-time power grid WebGIS visualization applications.

the paper introduces IRS to assist offloading, and the propagation Environment can be intelligently changed by changing the reflection unit of the IRS, This article proposes an IRS-assisted MEC power distribution Internet of Things system, and studies the gain effect of IRS in the MEC system. In this system, the single antenna equipment can choose to unload a small part of its computing task to the edge computing node of the distribution Internet of things through the multi antenna access point with the help of IRS. In this paper, the delay minimization problem of the whole system is established, the DNQ reinforcement learning algorithm is used to solve the problem, which can effectively change the coverage of smart substations.

The digitally simulated UHVDC system provides an all-round, full-process, and full-scenario high-fidelity training and teaching platform for the switching operation of the UHVDC system, which can fully meet the training requirements of the operation and maintenance personnel of the converter station. In order to solve the problem of inaccurate evaluation due to the existence of multiple operation procedures for an operation target, an improved digital simulation system based on multiple adaptive evaluation algorithms was designed: the teacher uses a modular combination method to generate a standard operating procedure as the main line, and then uses the trainee's simulated operating procedure as a supplement to jointly form a standard answer to adapt to the different operating procedures of the same operating task for the trainees. Based on this system, it can solve the problem of inaccurate evaluation caused by millions of answers in the simulation operation evaluation process. It provides fast, efficient and accurate evaluation results for the digital simulated UHVDC system switching operation procedure.

More and more high-power impact loads in the power grid are put into use. When the power is impacted, these loads will cause the power grid bus voltage fluctuations and reduce the power quality. Therefore, in order to accurately analyze the changes in the power system, it is particularly important to establish a reasonable impact load model. This paper takes the impact load data generated by the CT machine during exposure as an example to analyze the characteristics of the impact load. Based on the active power characteristics of the impact load, machine learning methods (such as support vector machines and long and short-term memory networks) are introduced into the impact load modeling, and the power waveform change law of the impact load is accurately established by this method. Finally, the effectiveness of the method is verified by simulation.

In this paper, a Transformer-based fast Monte Carlo reliability evaluation method for integrated energy systems is proposed. First, the faults of the system components are sampled and the corresponding minimum cut load amounts are calculated to obtain the sample data for training the machine learning model. Then, Transformer is used as a machine learning algorithm for mining the nonlinear mapping relationship between system component faults and the minimum cut load, and the estimation model of the minimum cut load under different faults is trained. Finally, the model is combined with Monte Carlo simulation method to randomly sample component states, and for each state, the minimum cut load amount is directly given by the trained estimation model, thus realizing fast evaluation of integrated energy system fast reliability. The proposed method is applied to the integrated energy system test case, which verifies its effectiveness.

The power consumption readings of sub meter and total meter of distribution transformer of low-voltage users follow the law of conservation of energy. The meter power loss rate of abnormal low-voltage users must also be abnormal. This paper studies the solution of the meter power loss rate under the four abnormal power consumption scenarios of single (multi) user and full (partial) period. The traditional linear solution method has accurate identification effect for the abnormal power consumption scenario of full period, but it cannot identify the abnormal power consumption scenario of partial period. In this paper, an improved artificial fish swarm algorithm is proposed. By adjusting the fixed step to the adaptive step, the power loss rate of each sub meter is obtained, and the abnormal power users are pinpointed. The research results are verified by simulation examples on IEEE European Low Voltage Test Feeder. The results show that the improved artificial fish swarm algorithm in this paper can identify abnormal power users for the above four abnormal electric field scenarios. The algorithm provides a new alternative for the identification of abnormal low voltage users.

Electromagnetic transient simulation program EMTP is a common simulation commercial software in power system. It can effectively analyze and study power system. In this paper, EMTP is used to build the power system simulation model, and a variety of short-circuit faults in the power system are simulated and analyzed. The results show that the results accord with the actual theory, and the waveform can accurately and intuitively investigate the dynamic characteristics of power system faults. In addition, through the simulation comparison and analysis between different faults, it can be seen that the three-phase short-circuit fault is the most serious fault in the power system, which should be avoided in the actual production and life. This shows that EMTP is a powerful tool for power system simulation research, and provides a reference for the actual equipment selection requirements of the project.

Communication system has high quality requirements for power supply. Realizing the effective monitoring of power supply system is an important measure to improve power quality. In order to better and effectively manage massive power information in complex environment and avoid communication power failure, a design method of distributed communication power monitoring system based on big data technology is proposed. The system operation performance is proposed, and the software function and operation process of the communication power monitoring system are simplified by using big data technology to improve the system monitoring accuracy. Finally, the experiment shows that the distributed communication power monitoring system based on big data technology has significantly higher response speed and relatively lower monitoring error in the actual application process.

The manual inspection for the damage state of the electric energy metering box consumes a lot of time, the workload is large, and the data storage is difficult. In order to solve these problems, this paper proposes an automatic detection method for the damage state of the electric energy metering box based on the YOLOv5 algorithm. The actual metering box pictures taken by the operation and maintenance inspectors are used as the training set, LabelImage is used to annotate the data set, and YOLOv5s model is used to train the data set. The experimental results show that the method proposed in this paper can accurately mark the position of the metering box lid and accurately predict its damage state. The average accuracy reaches 98%, which can meet the requirements for the detection accuracy of the power metering box damage state in the operation and maintenance inspection work.

The condensation on solid materials surface inside switchgear is an important reason threatening its safety and reliability. The formation of condensation is closely related to the temperature and humidity distribution inside the switchgear. A 3-D simplified finite element calculation model for the switchgear is established, including the bus bar, the wall bushing, the circuit breaker, the cables and other key components. Based on the electromagnetic-temperature-humidity multi-physical field coupling method, the temperature distribution inside the switchgear are calculated when the operating current flows through the bus-bar. Furthermore, the humidity diffusion process is also calculated when the relative humidity of external environment was 0.8, and the relative humidity inside the switchgear is obtained. The calculation results show that the surface humidity of the contact box of the circuit breaker is the highest whereas the temperature is the lowest, which is the location where the condensation is easy to occur.

As a large, complex system with wide distribution and high real-time, the safe, stable and reliable operation of the power system is inseparable from the power automation system. In this paper, an in-depth study is conducted on the key issues of this solution in the process of software cross-platform integration around the EPRI graphic center method, combined with the power data interface standard. The dispatch center graphics system and the dispatch center power graphics application method are discussed in detail in the paper. In addition, the paper also explains the online calibration system for relay protection ratings with smart grid dispatching technology support system. The methods and sample systems in this paper have been practically applied in large scale power grid dispatching centers, providing a reliable guarantee for the safe and stable operation of the power grid.

The metro stray current, as the driving source which causes the magnetic bias of the urban network transformer, has the characteristics of rapid change, complex propagation path, and many influencing factors.It's unknown where the stray current leaks from, and its specific value cannot be obtained through measurement methods.Therefore, this paper studies the characteristics of transformer neutral magnetic current bias based on the measured data and fault recording data in the process of measurement, and analyzes the influence of stray current on transformer in urban network.

In this paper, dissolved gas analysis (DGA) and statistical distribution model (SDM) were used to predict the health index (HI) of dissolved gas in transformer oil. First, the individual DGA data are classified according to transformer ages ranging from 1 to 4 years. Then, representative fitting models were selected and extrapolated from 5 to 25 years. The inverse cumulative distribution function (ICDF) of the selected distribution model was used to calculate the single conditional parameter data from 5 to 25 years. Finally, the traditional scoring method is used to estimate the future HI value. The results show that DGA parameters can be expressed by exponential equation based on statistical model. The predicted values of DGA health index of transformer oil from 1 to 7 years were basically consistent with the calculated values, and the DGA score was 100 points. By the 20th year, the DGA score had dropped to 75, requiring timely monitoring. The research results can provide powerful data support and theoretical reference for transformer life prediction.

In order to meet the needs of safe and efficient patrol operation and maintenance of modern smart grid, aiming at the poor quality of current transmission line patrol inspection, a design method of transmission line patrol data visualization system based on 3D GIS is proposed. By optimizing the system hardware structure configuration combined with 3D GIS technology, the function and structure of transmission line visual management system are introduced. The accurate collection and processing of transmission line inspection data and the display of inspection route are realized by using three-dimensional GIS technology. Finally, the experiment shows that the transmission line inspection data visualization system based on Three-dimensional GIS has higher practicability and accuracy in the process of practical application, and fully meets the research requirements.

In order to reduce the occurrence of power outages with repeated occurrences in the distribution network, this paper first defines the quantitative index of the concept of repeated occurrences. The FP-Growth data mining algorithm based on the optimal frequent itemset is proposed to obtain the correlation between the power outage factors. Combined with the fuzzy analytic hierarchy process, the main reasons for repeated power outages are obtained. The analytic hierarchy process combining subjective and objective weights is used to comprehensively evaluate the risk of repeated power outages in the distribution network. This paper realizes the early warning of power outage risk based on the comprehensive probability value of power outage. Finally, an actual distribution network in Chongqing is taken as an example to verify the practicability and effectiveness of the method.

In order to master operation status of the electronic current transformer(ECT), application investigation and defects statistical analysis were conducted on ECT of 110(66)kV~1000kV applied in smart substation of the State Grid Corporation of China(SGCC). The defect location, defect cause and defect type of ECT with different principles are analyzed. The results indicate that the defects of ECT are mainly concentrated in the acquisition unit, the defect rate is closely related to the reliability of electronic components, the technical level, production process and quality control of the manufacturer. In view of the typical defect analysis, the corresponding solution measures are put forward to provide reference for the subsequent research and application of ECT.

As the proportion of wind power generation continues to increase, accurate forecasting of wind power output is of great significance to the smooth operation of the entire power grid. However, due to the greater impact of environmental factors, wind power generation has strong randomness, and it becomes difficult to accurately predict the power generation. Thus, a new hybrid model for wind power generation prediction combining GRU neural networks and similar days' characters analysis is proposed to address solve this problem. The prediction method employs grey relation analysis to screen similar days, which not only reduces the amount of data required to train the model, reduces the computational complexity, and improves the training speed, but also improves the prediction accuracy based on the selected datasets. In addition, this method also filters and processes the data through box-plot analysis and linear smoothing, which further improves the prediction accuracy of the model. The results show that compared with a single GRU network, the MAE of this method has dropped by 1.89, RMSE has dropped by 1.9, and MAPE has dropped by 11.07%. Obviously, the prediction model based on similar days extraction has obvious advantages.

Infrared thermography technology is widely used in the thermal condition detection of insulators due to its advantages of non-contact, sensitive, online detection. To realize the automatic detection of the operating condition of insulators in complex environments, this paper proposes a method for the recognition and location of the insulator based on Region-based Fully Convolutional Networks (R-FCN). The model was trained and tested on the constructed insulator infrared data set, compared with the SSD model. The results showed that the R-FCN detecting insulators can not only accurately locate insulators, but have an AP (average precision) value as high as 89.2%. Therefore, the findings in this paper have verified that R-FCN has great advantages in the recognition and location of infrared images of insulators and has practical application value.

In the edge detection of foreign object hanging image of high voltage transmission line, it is easy to appear that multiple responses will appear at one image edge point, which affects the detection effect. Based on the improved Canny operator, an edge detection method for foreign matter suspension image of high voltage transmission line is designed. The collected image is preprocessed in three steps: gray processing, optical correction and noise reduction, so as to better reflect the characteristics of the original image and improve the image quality. The non-uniform distribution of potential energy of foreign body hanging image data field is used to locate the image area of foreign body hanging. The morphological filter can extract the local noise and make the image clearer. The Canny operator is improved to obtain the partial derivative of the distance measurement function and automatically update the threshold to eliminate the multi-level response. The test results show that the method in this paper is better than the image edge detection method based on Canny operator and Sobel operator in three indexes: positive detection rate, false detection rate and missed detection rate.

The radioactive settlement of nuclear explosion is simulated by Lagrange particle diffusion model. The simulated settlement map and the measured data map are digitally extracted into the same format. The effectiveness measurement (MOE) method and normalized absolute difference (NAD) method are used to conduct numerical comparative analysis between each dose simulation area and the measured area.

The 500kV transmission line is exposed to the outdoor for a long time. It is affected by complex climate charge change and other factors which leads to line connection parts bolt loosening, wire breaking and fixture damage and other line failures. In order to ensure the stable transmission of electric energy, power operators need to wear shielding suits and work in the high-risk and high-voltage environment. Use of electric power operation robot instead of manual operation is an effective way to liberate maintenance staff labor. But robots still have some problems such as low degree of automation and low efficiency of power operation. Machine vision detection technology in recent years has been widely used in major areas including deep learning as emerging visual detection technology shows excellent performance. In this paper, the vision detection algorithm is studied respectively for the bolt fastening end working device and wire repairing end working device of the live transmission line robot to improve the operating efficiency of the robot.

The Energy Internet is a leading development direction for the modernized and intelligent transformation of the power grid, and a new type of infrastructure that supports the high-quality development of the economy and society. With the access of a variety of mobile terminals, security is one of the most important challenges faced in the construction of Energy Internet. Research on reliable networking and data forwarding strategies on the edge is of great significance to its development. On the basis of analyzing the requirements of typical application scenarios, we introduce in this paper a secure data transmission algorithm based on confidence of wireless opportunistic networks for Energy Internet to resist the influence of malicious behaviours. The simulations of real scenes confirm the advantages of introducing our algorithm on parameters such as the success rate and the delay of data transmission.

Aiming at the low cleaning rate of the traditional multi-source heterogeneous power grid big data cleaning model, a multi-source heterogeneous power grid big data cleaning model based on machine learning classification algorithm is designed. By capturing high-quality multi-source heterogeneous power grid big data, weight labeling of data source importance measurement, data attributes and tuples, and constructing Tan network based on the idea of machine learning classification algorithm, the data probability value is finally used to complete the classification and cleaning of inaccurate data. Experiments show that the model based on machine learning classification algorithm can effectively improve the imprecise data cleaning rate compared with the traditional model to solve multi-source heterogeneous imprecise data cleaning.

In view of the challenges faced by the current HV cable O&M management, such as the growth of equipment scale, the severe security situation, the lack of comprehensive perception on equipment status, and the ability of intelligent analysis and decision-making to be improved, it was proposed to build a HV cable intelligent sensing IoT based on new sensors such as intelligent earthing box, PD intensive care unit, intelligent ground landmark and face recognition system for terminal stations, so as to comprehensively improve the quality and efficiency of HV cable O&M management. A pilot project was built in Hongqiao area in Shanghai, forming typical application scenarios such as IoT intelligent disposal, integration of monitoring and detection data in terminal stations, panoramic intelligent patrol inspection for ensuring power supply.

To contribute to the intelligence and knowledge of power grid regulation and control operations, this paper presents a method of power grid regulation knowledge modeling based on ELG (Event Logic Graph), which includes an event word extraction based on a predicate-argument model, an event chain extraction and fusion based on event similarity theory, an event generalization based on a soft-pattern algorithm, and an event relationship recognition based on rule pattern matching method and joint constraints. Finally, this paper uses events as nodes and event relationships as directed edges to construct an affair graph stipulated by the power grid regulation and control regulations. The ELG is also called the new generation knowledge graph. But the knowledge graph can only describe the existence of entities and the upper and lower associations between entities. ELG can explain the inheritance, causality between entities and the logic of affair evolution, and the probability of transition between legacy and causality. Therefore, knowledge modeling based on ELG has intelligent advantages. Also, compared with ontology-based knowledge modeling methods, the method proposed in this paper can realize the dynamic representation of control operation knowledge, can express the logic of behavior and logic of operation, and also has higher retrieval accuracy.

This paper takes a data center air-conditioning cold source system as the research object. According to the historical operating data of the cold source system in the transition season, a cold source model is built on the EBSILON platform. The total energy consumption of the cold source system is the research goal. This paper establishes an overall optimization strategy based on PSO-SA. A simulation experiment was conducted on a typical day in the transition season, and the results showed that the optimization strategy can achieve 21.68% energy saving based on the original operation mode when the wet bulb temperature in the transition season is low.

Currently, the independent design and development of power grid automation system cannot meet the urgent requirements of integrated system for electric dispatching, monitoring and synthetic analysis and decision-masking. In accordance with this situation, a general power grid dispatching control graphics software architecture based on the modular hierarchical theory is proposed. The architecture extracts and abstracts the common modules of different system graphics software architectures to build an integrated basic development platform. Based on this platform, an integrated graphical interactive software for power grid dispatching, power distribution network or substation supervision can be quickly developed. In this paper, the overall architecture, modular hierarchical theory, graphics general API and the key technologies for this architecture are described in detail. This architecture has been applied to the development of multiple power grid control graphics software, and the engineering application is performing well in reality. In a word, the architecture proposed in this paper satisfies the needs of power grid control integration, and effectively reducing system