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Review of Key Technologies in New Power System Based on Artificial Intelligence Empowerment DUAN Junfeng, LI Chenkun, YAO Wenxuan, GUO Siyuan Hunan Electric Power    2024, 44 (1): 1-10.   DOI: 10.3969/j.issn.1008-0198.2024.01.001 Abstract （239）      PDF（pc） （5512KB）（412）       Knowledge map    Save Based on the important role of artificial intelligence technology in promoting the intelligence of new power systems, this paper summarizes the current application status, technical challenges, and future development directions of artificial intelligence in new power systems. Firstly,the paper introduce the characteristics and requirements of the new power system. Then, the paper discusses the key application areas of artificial intelligence in new power systems, including the security, stability and control of large power grids, integrated collaborative analysis of source network, load storage, intelligent operation, inspection and management of power systems, as well as active distribution networks and microgrids. Finally, the paper analyzes the technical challenges faced by artificial intelligence in the new power system and proposes relevant suggestions. Reference | Related Articles | Metrics

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Transient Characteristic of MOESFET Based on Cosimulation Simulink with COMSOL GAO Bing, WANG Shuai, ZHONG Yongheng, SUN Yasen, ZHANG Shangchen, ZHOU Jie Hunan Electric Power    2022, 42 (5): 1-7.   DOI: 10.3969/j.issn.1008-0198.2022.05.001 Abstract （237）      PDF（pc） （5562KB）（390）       Knowledge map    Save Power devices are one of the weak links in power electronic systems, and their failure has obvious multi-scale characteristics. It is of great significance to build a transient model that can consider the multi-scale characteristics of power devices for device condition monitoring and aging evaluation. Therefore, this paper takes MOSFET as the research object, constructs the field circuit joint simulation model of power device Simulink and COMSOL, and realizes the transient characteristic analysis of devices considering the interaction of device switching information and macro physical information by selecting the on current and on voltage drop as the model interaction information. The average temperature at the chip (shell temperature), the average temperature on the surface of the chip (junction temperature), the conduction voltage drop, the chip resistance and the maximum displacement of the solder layer are analyzed. The results show that the model can effectively consider the switching characteristics of devices and the interaction between macro fields, and lay the foundation for the digital twin model of devices. Reference | Related Articles | Metrics

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Fault Analysis and Management of Feedwater Pump Turbine Shaft Sealing System for a 1 000 MW Unit YU Xinggang, WEI Haifeng, ZHU Taichun, GUO Xuhong, JIANG Bohua Hunan Electric Power    2022, 42 (5): 119-122.   DOI: 10.3969/j.issn.1008-0198.2022.05.021 Abstract （83）      PDF（pc） （1475KB）（215）       Knowledge map    Save A 1 000 MW unit in a newly-built coal-fired power plant adopts a steam-driven feed water pump with a capacity of 100% boiler maximum continuous rating. During commissioning, the shaft seal system of the feed water pump turbine of this unit has the faults of water entrainment of shaft seal steam and abnormal noise of the shaft seal pipe at the side of the feed water pump. Through adjustment and analysis, it is found that the causes of the above-mentioned failures are unreasonable design of shaft seal steam return pipe and imperfect installation of shaft seal steam pipe sleeve in condenser. The fault of shaft seal system of feed water pump turbine has been successfully solved by installing hydrophobic water seal cylinder at the lowest point of shaft seal steam return pipeline and installing heat insulation on shaft seal steam pipeline in condenser. Reference | Related Articles | Metrics

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Research on Multi-Level Dispatching Coordination Control Strategy and Auxiliary Decision of AC-DC Hybrid Power Grid TAN Wenzhong, WANG Qisheng, MEI Hongxing, XIE Hao, ZHANG Siyuan Hunan Electric Power    2022, 42 (5): 48-52.   DOI: 10.3969/j.issn.1008-0198.2022.05.008 Abstract （93）      PDF（pc） （2055KB）（131）       Knowledge map    Save At present, the new type of AC-DC hybrid power grid urgently needs new dispatching control methods. Based on the static partitioning and online system auxiliary decision-making model, this paper proposes a control method based on the combination of optimal dynamic partitioning and minimum low-voltage load loss. According to the integrated control strategy, the provincial dispatch cost control objective function based on dynamic partition and load shedding coordinated optimization and the regional dispatch low-voltage control objective function based on section sensitivity are respectively constructed, and the specific connotation of the two control levels and coordinated optimization decision-making are clarified. The validity of the proposed model and method is verified by a simulation example. Reference | Related Articles | Metrics

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Development Status and Trend Analysis of Standard Digitization in Power Grid Enterprise ZHANG Lan Hunan Electric Power    2023, 43 (1): 95-98.   DOI: 10.3969/j.issn.1008-0198.2023.01.016 Abstract （209）      PDF（pc） （3656KB）（123）       Knowledge map    Save Standard digitization transformation facilitates standards in power grid enterprise to be more efficient, transparent, cooperative and smart, and will also make standard digitization in power grid to guide,regulate and support a healthy and ordered development of digital transformation in power grid. Based on the background of standard digitalization, this paper introduces the characteristics and status quo of standard digitalization of power grid enterprises, sorts out the problems faced by the standard digitalization of power grid enterprises, and analyzes the development trend of the standard digitalization of power grid enterprises.Some suggestions on the standardization and digitization of power grid enterprises are put forward. Reference | Related Articles | Metrics

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Study on Wind-Proof of Indirect Air Cooling Tower with Vertical Layout CHEN Yun, WANG Limin Hunan Electric Power    2022, 42 (5): 16-21.   DOI: 10.3969/j.issn.1008-0198.2022.05.003 Abstract （142）      PDF（pc） （6457KB）（122）       Knowledge map    Save The air cooling system is greatly affected by the change of external climate. When the wind speed increases or the temperature rises, the heat transfer capacity of the air cooling radiator decreases, thereby leading to the rise of the unit's back pressure. In order to make sure the unit operating safely, some measures should be taken to reduce the influence of high wind speed. In this paper, the flow field distribution and heat dissipation capacity of four models are simulated under high wind speed. According to the analysis and comparison of flow field distribution and heat dissipation capacity data, the heat dissipation capacity of indirect air-cooling tower is as follows: wind-proof wall outside the tower, adjusting shutter, cross wall inside the tower, without any wind-proof measures. Reference | Related Articles | Metrics

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Heater Arrangement Method of 12 kV Switchgear Decondensation Based on Synthesizing Evaluation Function XU Junwei, SHU Shengwen, ZHAN Zhaoxuan, BIAN Zhiwen, LIN Yihong Hunan Electric Power    2023, 43 (2): 8-13.   DOI: 10.3969/j.issn.1008-0198.2023.02.002 Abstract （84）      PDF（pc） （2748KB）（102）       Knowledge map    Save In high humidity environment, the switchgear is easy to get damp and form condensation, resulting in a sharp decline in the insulation performance of the electrical equipment in the switchgear. In order to improve the ability of switchgear to cope with humid environment, this paper takes 12 kV high-voltage switchgear as an example to propose a comprehensive evaluation method of heater layout which considers temperature rise level, temperature rise uniformity and dehumidification capacity. Firstly, based on the comprehensive evaluation method of heater layout, the optimal heater layout test is carried out to select the optimal heater layout scheme. Then, the decondensation test is carried out on the basis of the optimal configuration test of the heater to verify the dehumidification performance of the heater layout scheme in the high humidity environment. Finally, combined with the numerical simulation of temperature-fluid multi-physical field, the distribution of temperature and flow field under the condition of heater installation is studied. The results show that the three 50W heater schemes are the best among the two selection strategies. The optimal heater arrangement scheme can completely remove condensation within 4.5h without causing excessive heating of insulation parts. Reference | Related Articles | Metrics

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Electromagnetic-Fluid-Thermal Field Analysis of Power Cable under Vertical Laying Mode QU Bo, YANG Juntao, LI Xin, XIANG Xingyao, SHU Shengwen Hunan Electric Power    2023, 43 (2): 24-31.   DOI: 10.3969/j.issn.1008-0198.2023.02.005 Abstract （84）      PDF（pc） （4304KB）（176）       Knowledge map    Save The temperature distribution is one of the key factors that determine the operation of the power cable, and it is mainly affected by the running current, the laying mode and the operating environment. In order to study the temperature distribution characteristics of cables under the vertical laying mode, the paper takes the cable shafts of high-rise buildings as the research object, and builds a simplified three-dimensional multi-physics simulation model of the cable shafts. The finite element method is used to calculate the fluid and temperature distribution inside the cable shafts, and the temperature variation trend is analyzed. Then, the influence of factors such as running current and fire blocking material on the temperature distribution of the cable is comparatively studied. The research results show that compared with the horizontal laying mode, the vertical laying of the cable is more susceptible to the influence of the air flow in-side the cable shaft, resulting in a large difference in the temperature distribution between different parts of the cable. At the same time, the increase of load current and the addition of fire blocking materials will cause the increase of cable temperature and the change of temperature distribution between different floors. Reference | Related Articles | Metrics

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Control Strategy of LCL Grid-Connected Inverter Based on Improved Weighted Current Control LING Zhiyong, ZHOU Zhifei, LI Shengqing, YAO Hongde Hunan Electric Power    2023, 43 (2): 39-45.   DOI: 10.3969/j.issn.1008-0198.2023.02.007 Abstract （115）      PDF（pc） （4395KB）（168）       Knowledge map    Save Aiming at the problems that the traditional weighted average current (WAC)control strategy does not consider the digital control delay, and causes the phase lag of the system, which leads to the reduction of system bandwidth and poor robustness, the WAC control strategy of combination of quasi-proportional resonance control and lead compensator is proposed. Firstly, the capacitor current feedback is introduced to suppress the reverse resonance peak. Secondly, the lead compensator is connected in series at the transfer function of the inverter bridge to improve the phase margin of the system. Finally, the quasi-proportional resonant controller is used as a current regulator to Increase the fundamental frequency gain and reduce the static error of the system. It is verified by simulation that the proposed control strategy has good adaptability to weak power grids, and the harmonic distortion rate of grid-connected current is reduced from 1.84% to 0.26%, thereby enhancing the robustness of the system and improving the quality of grid-connected current. Reference | Related Articles | Metrics

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Analysis on Influence of Separate Operation of 500 kV Bus of UHV Xiaoxiang Station on Hunan Power Grid LIU Yongyan, GAN Wangwei, ZHANG Yan, XIAO Pei, CUI Ting, GUO Hu Hunan Electric Power    2023, 43 (2): 112-116.   DOI: 10.3969/j.issn.1008-0198.2023.02.019 Abstract （83）      PDF（pc） （2529KB）（142）       Knowledge map    Save After the commissioning of the 1 000 kV UHV AC double-circuit line from Xiaoxiang—Ganjiang, the reactive power support capability of the inter-provincial AC channels has been enhanced, and the system stability has been enhanced, but it also leads to the increase of the system short-circuit current. In order to ensure the transient voltage stability of Hunan power grid, it is still necessary to put forward the requirements for the start-up and rotation of units in the province, which limits the power supply capacity and operational flexibility of the power grid. Aiming at this problem, the optimization of 500 kV grid structure in Hunan power grid is studied, and the optimization scheme of 500 kV bus-bar operation in UHV Xiaoxiang station is put forward to reduce the impact of near-area short-circuit fault on the system. It can improve the transient voltage stability level and the power supply capacity of power grid, and provide technical support for the safe and stable operation of Hunan power grid. Reference | Related Articles | Metrics

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Design and Application of Complex Terrain and Omni-Directional Modular Quick Installation Insulating Tower Platform BAI Jianfeng, LEI Dongyun, XIAO Liyong, LI Jinliang Hunan Electric Power    2022, 42 (4): 64-69.   DOI: 10.3969/j.issn.1008-0198.2022.04.013 Abstract （105）      PDF（pc） （4301KB）（185）       Knowledge map    Save With the increasing demand for reliable power supply in distribution network, it is urgent to carry out uninterrupted power supply in the whole region. In order to adapt to the live working environment of power distribution under different terrain, the advantages and disadvantages of common live working insulation platforms are compared and analyzed, and an complex terrain and omni-directional modular quick installation insulation tower platform is designed in this article. A tower body, a hoop holding device, an auxiliary platform and a working platform is comprised in the device.Modular tower section is adopted, inverted or rotary installation mode is designed, and the method of fixing relying on concrete pole is designed in this design. It can meet the three main functional requirements of quick disassembly and quick assembly, multi-purpose and heavy load. The device is suitable for the live working environment of 10 kV overhead distribution line under complex and changeable terrain. The problems of difficult installation and connection of common insulation platforms in rural areas, high requirements for ground flatness, small application scenarios are solved. Reference | Related Articles | Metrics

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Three-Phase Load Imbalance Management Method Based on Improved Knapsack Algorithm for Manual Phase Change Station Area ZHAO Ruolan, JIANG Fei, HE Zhenwu, YAO Peng, GUO Qi, PEI Xiangyu Hunan Electric Power    2023, 43 (1): 103-109.   DOI: 10.3969/j.issn.1008-0198.2023.01.018 Abstract （159）      PDF（pc） （5847KB）（120）       Knowledge map    Save In view of the high degree of three-phase unbalance in the distribution station area and the low efficiency of the traditional manual phase change, a manual phase change optimization method based on the improved knapsack algorithm is proposed. The multi-objective phase change optimization model is constructed by considering the degree of three-phase unbalance and the number of phase changes. The phase change problem is abstractly transformed into a multi-pack model, and the algorithm is improved by introducing the idea of layered partitioned parallel search (LPPS). The actual data of a residential distribution area are used to analyze the case, and the improved knapsack algorithm is used to calculate the phase change scheme of the distribution area. Compared with the traditional knapsack algorithm, the number of phase changes is reduced while ensuring the treatment effect, which is conducive to improving the economic operation efficiency of the distribution area. Reference | Related Articles | Metrics

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Summary of Reliability Research on High Voltage Electrical Device in Substation MA Zhaoxing, CHEN Hao, TANG Yi, SHA Haoyuan, JIANG Minyi Hunan Electric Power    2023, 43 (2): 53-59.   DOI: 10.3969/j.issn.1008-0198.2023.02.009 Abstract （134）      PDF（pc） （1104KB）（209）       Knowledge map    Save Based on the reliability research of high-voltage electrical equipment in substations, this paper introduces the development of the reliability research of high-voltage electrical equipment, discusses the reliability analysis methods of common electrical equipment, and compares the advantages and disadvantages of the analytical and analog methods, the optimal application situation is analyzed, and the combination method and state method under complex system are studied. The future trend of reliability analysis based on multi-methods cross-fusion is prospected. Reference | Related Articles | Metrics

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Application of Distributed Energy Storage in Distribution Networkand Its Economic Evaluation ZHAO Yuting, LYU Dangzhen, WAN Dai, ZHAO Yongsheng Hunan Electric Power    2022, 42 (5): 53-59.   DOI: 10.3969/j.issn.1008-0198.2022.05.009 Abstract （161）      PDF（pc） （1120KB）（229）       Knowledge map    Save According to the research and development and application status of distributed energy storage power station in distribution network, the application scenario and price system of distributed energy storage power station in distribution network are analyzed, and the principle of location and capacity selection of distributed energy storage power station in distribution network is put forward.This paper establishes a mathematical model for economic evaluation of distributed power stations in distribution network, makes economic evaluation based on an example of distributed energy storage power stations in distribution network,and proposes suggestions on improving the comprehensive benefits of distributed power stations in the distribution network. Reference | Related Articles | Metrics

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Deadbeat Control of LCL Photovoltaic Inverter Based on Compound Prediction LI Shengqing, YAO Xin, FENG Haotian, ZHANG Dong, TANG Xinyun Hunan Electric Power    2022, 42 (4): 40-45.   DOI: 10.3969/j.issn.1008-0198.2022.04.008 Abstract （159）      PDF（pc） （2697KB）（104）       Knowledge map    Save Aiming at the problems of time delay and low prediction accuracy of traditional deadbeat control, a deadbeat current control based on composite prediction is proposed. This method first analyzes the reasons for the time delay and low prediction accuracy. Then, when the load is stable, Lagrange interpolation method and repeated prediction are combined to improve the current prediction accuracy. When the load changes, adaptive forward linear current prediction is introduced to shorten the system oscillation time and enhance the dynamic response ability. Finally, the two methods are combined for control. The inverter output current is predicted one beat in advance and the sampling reference current is predicted two beats in advance, which solves the problem of time delay. The simulation results show that this method reduces the harmonic content by 92% and the oscillation time by 50% compared with that before compensation. It has higher prediction accuracy and dynamic response ability, and better control effect. Reference | Related Articles | Metrics

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Design and Simulation of Equalization Circuit for Lithium-Ion Battery ZHU Hao, LIAO Honghui, E Jiaqiang, DENG Yuanwang Hunan Electric Power    2022, 42 (4): 28-32.   DOI: 10.3969/j.issn.1008-0198.2022.04.006 Abstract （143）      PDF（pc） （3032KB）（228）       Knowledge map    Save In applications such as energy storage plants and pure electric vehicles, cell units are integrated in the battery pack in series and parallel,the battery packs may not be consistent with each other when in use, and this inconsistency can affect battery life and range. Aiming at this phenomenon, the paper designs the balanced topology circuit between the module and the module, analyzes the balanced principle of the designed circuit,builds the energy transfer model and the module internal balanced model in the Simulink/Simpowersystem, and simulates the equilibrium topology.The results show that the designed equalization system can realize the energy equalization of the battery. Reference | Related Articles | Metrics

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Effect of Organic Pollutant Infiltration on Anti-Flashover Performance of Methyl Silica Superhydrophobic Coatings WANG Shengwu, ZOU Qiaoge, LI Li, CHEN Junwu, XIE Yi Hunan Electric Power    2023, 43 (2): 3-7.   DOI: 10.3969/j.issn.1008-0198.2023.02.001 Abstract （82）      PDF（pc） （3667KB）（202）       Knowledge map    Save The deposition and infiltration of organic pollutants on the surface of methyl silica superhydrophobic coatings will lead to a decrease in the self-cleaning properties of the coatings, which in turn will lead to a decrease in the insulation strength of the coatings under dirty and wet environmental conditions. There is a lack of research on the effect of organic fouling on the insulation strength of methyl silica superhydrophobic coatings. The insulation strength of the coating samples under dirty and wet conditions is reflected by measuring the leakage current amplitude of the coating samples after they are wetted with alkane organic substances in different degrees and ways. The results show that the leakage current amplitude of the surface of methyl silica superhydrophobic coating increases by more than 50% when the infiltration area of organic pollution is increased to 3 times under the experimental conditions. The leakage current amplitude of the coating is decreased by about 16% by increasing the dispersion degree of organic pollution sites. Under the experimental conditions of heavy organic infiltration, the static contact angle and rolling angle of methyl silica super-hydrophobic coating drops are decreased by 10° and increased by more than 7° respectively. Reference | Related Articles | Metrics

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Measures of Performance Optimization and Improvement of Three-Phase Inconsistent Protection for Circuit Breaker GUO Yang, CHEN Hao, GAO Shiyu, GU Hao, LI Yifeng Hunan Electric Power    2022, 42 (5): 90-94.   DOI: 10.3969/j.issn.1008-0198.2022.05.016 Abstract （185）      PDF（pc） （4167KB）（109）       Knowledge map    Save Based on the typical secondary circuit, this paper introduces the principle of three-phase inconsistent protection in high-voltage power system, analyzes the causes of protection maloperation from the aspects of circuit insulation fault, artificial factors, improper setting of pressure plate and so on, and puts forword the optimization and improvement measures. The application practice shows that the optimized measures are feasible and effective, and the performance of three-phase inconsistent protection is greatly improved. Reference | Related Articles | Metrics

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Power Flow Calculation Method in Loop-Closing Distribution Network Based on Bus Voltage Phasor Acquisition CHEN Chenggong, ZHU Yulan, PANG Muchan Hunan Electric Power    2023, 43 (2): 102-107.   DOI: 10.3969/j.issn.1008-0198.2023.02.017 Abstract （76）      PDF（pc） （2555KB）（201）       Knowledge map    Save The traditional calculation method relying on power grid modeling and parameter accuracy is not suitable for the power flow calculation in loop-closing distribution network.To solve this problem, a new power flow algorithm based on bus voltage phasor acquisition is proposed, which can realize the on-line calculation of power flow in distribution network conveniently. The on-line computing module developed based on the algorithm has a good effect, which verifies the validity and practicability of the algorithm. Reference | Related Articles | Metrics

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Diagnosis of Circuit Breaker Current Characteristics Based on LSSA-BP Neural Network JIA Hao, ZHANG Lian, ZHANG Shangde, ZHAO Mengqi, ZHAO Na, HUANG Wei Hunan Electric Power    2022, 42 (5): 36-41.   DOI: 10.3969/j.issn.1008-0198.2022.05.006 Abstract （117）      PDF（pc） （3269KB）（122）       Knowledge map    Save As a device that can widely play a role in security protection in various power system applications, high voltage circuit breaker has great significance for its fault diagnosis research. Aiming at the problems of slow convergence speed and insufficient convergence accuracy of traditional BP neural network, an improved sparrow search algorithm is proposed to optimize the BP neural network. The model obtains more reasonable initial parameters by introducing Logistic chaotic map when the sparrow algorithm initializes the population, and introduces dynamic adaptive weight, Cauchy mutation strategy and reverse learning strategy in position update and optimal solution update respectively, so that the average accuracy of the model for circuit breaker fault classification diagnosis is close to 100%, which indicates that the improved BP neural network has higher accuracy. Reference | Related Articles | Metrics

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Treatment of Oily Wastewater from Substation Accident Oil Pool Based on Process of Magnetic Flocculation and Electrocatalytic Oxidation WAN Tao, CHE Yao, LIU Heng, ZHAO Ruidun, ZHU Qiaoyun, XIANG Jingjing, ZHANG Lei Hunan Electric Power    2022, 42 (5): 69-74.   DOI: 10.3969/j.issn.1008-0198.2022.05.012 Abstract （112）      PDF（pc） （2729KB）（168）       Knowledge map    Save In view of the characteristics of the oil pool wastewater containing a large amount of mineral insulating oil in substation, the combined process of magnetic flocculation and electrocatalytic oxidation is adopted to treat the oil containing wastewater, the flocculation effect of magnetic flocculation and conventional flocculation is compared, and the effect of electro-catalytic oxidation process parameters on oil removal rate in oil-bearing wastewater is studied. The results of dynamic simulation tests show that the combined process has a good effect on the treatment of oil-containing wastewater from the oil pool of a substation accident. The removal rates of oil, chemical oxygen demand,turbidity and ammonia nitrogen are 96.99%,85.98%, 90.85% and 78.86% respectively. The effluent quality meets the first-class standard of Comprehensive Wastewater Discharge Standard. Reference | Related Articles | Metrics

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Auxiliary Judgment Method of Single Phase Grounding Fault in Distribution Network Based on Distribution Automation System LUO Xuelian, CHEN Chenggong, LIU Zhihao, ZENG Huanyue Hunan Electric Power    2022, 42 (5): 85-89.   DOI: 10.3969/j.issn.1008-0198.2022.05.015 Abstract （118）      PDF（pc） （2857KB）（97）       Knowledge map    Save Aiming at the problems of high cost, low line selection efficiency and low success rate of grounding line selection device in distribution network, based on the steady state zero sequence quantity of distribution automation master station system, a grounding fault auxiliary judgment module based on zero sequence impedance comparison and historical data reference is developed. Firstly, the electrical characteristics of 10 kV distribution network under single phase grounding fault are analyzed in detail, and a grounding line selection method is obtained according to the principle of zero sequence impedance comparison. Secondly, through the statistics of historical grounding data, the probability of grounding fault in distribution network lines is calculated, and the historical fault quantity, important degree mark quantity and zero sequence current are weighted by entropy method, so as to form an auxiliary judgment module of single phase grounding fault in distribution network relying on distribution automation system. Finally, the case analysis shows that this module has high accuracy in line selection. Reference | Related Articles | Metrics

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Cause Analysis and Preventive Measures of Wind Turbine Blade Tower Sweeping LUO Yanfei, XIAO Changyuan , SUN Maowen, LUO Shengxi, ZHANG Hualian Hunan Electric Power    2023, 43 (1): 116-120.   DOI: 10.3969/j.issn.1008-0198.2023.01.020 Abstract （246）      PDF（pc） （4564KB）（198）       Knowledge map    Save In recent years, there have been a number of blade tower sweeping failures of wind turbine in China, which have seriously affected the safe operation of wind turbines, and also brought a lot of economic losses. This paper analyzes the causes of blade tower sweeping failure in a wind farm from the aspects of clearance design, hoisting maintenance, blade quality, unit operation control, site adaptability, simulation restoration, etc. It is determined that the blade tower sweeping in the wind farm are caused by turbulence overrun, negative shear, and blade installation angle dislocation. Preventive measures are given for different tower sweeping causes, and some suggestions are put up for the clearance design of new models. Reference | Related Articles | Metrics

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Analysis and Research of On-Line Energy Consumption Monitoring Model for Thermal Power Units NIE Tao, SHAO Feng, YANG Wenzheng, HE Xinrong , WANG Zhong′ao Hunan Electric Power    2023, 43 (2): 60-65.   DOI: 10.3969/j.issn.1008-0198.2023.02.010 Abstract （91）      PDF（pc） （1192KB）（215）       Knowledge map    Save Because of the limitation of on-line energy consumption measurement condition and instrument measurement precision, the coal consumption of on-line monitoring system usually has big error.To solve this technical problem, this paper adopts the state equation of thermal economy of power plant to dynamically solve the steam turbine heat rate, applying the idea of energy mass balance, the steam water distribution matrix equation of the whole thermal system is established.At the same time, the dynamic fluctuation characteristics of boiler efficiency are deeply studied, the factors of coal quality ash and heat dissipation are analyzed , the theoretical calculation models of exhaust heat loss, solid incomplete combustion heat loss and heat dissipation loss are established.For the dynamic calculation of auxiliary power consumption rate, the emphasis is on the accuracy of the electric meter and the allocation method of the public part of the power supplied to the factory. The online calculation accuracy of the unit energy consumption model is verified and the test results show that the on-line energy consumption calculation and monitoring model can meet the accuracy requirements of ASME standards. Reference | Related Articles | Metrics

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Structural Strength Design of Outdoor Installation Protection Equipment ZHANG Yuan, ZHU Lijuan Hunan Electric Power    2023, 43 (1): 79-83.   DOI: 10.3969/j.issn.1008-0198.2023.01.013 Abstract （72）      PDF（pc） （5033KB）（89）       Knowledge map    Save The paper proposes a structural design method of sub unit, uses simulation software to analyze the structural strength design, and achieves the structural strength requirements through test verification, which has certain reference value for the subsequent device design under similar working conditions. Reference | Related Articles | Metrics

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Analysis of End Screen Dielectric Loss Measurement for Capacitive Current Transformer CAO Wenbin, CHEN Ruizhen, LUO Wei Hunan Electric Power    2023, 43 (1): 99-102.   DOI: 10.3969/j.issn.1008-0198.2023.01.017 Abstract （114）      PDF（pc） （3585KB）（136）       Knowledge map    Save The dielectric loss test of the end screen is of great significance for the detection of moisture defects in capacitive current transformers. The regulations stipulate that when the insulation resistance of the end screen of the current transformer cannot meet the requirements (less than 1 000 MΩ), the dielectric loss of the end screen to the ground should be measured to further judge its insulation status. In this paper, from the aspect of structure and dielectric loss test principle of capacitive current transformer, with the help of equivalent circuit, combined with actual test cases, the dielectric loss of current transformer is analyzed when the primary winding is suspended, the primary winding is grounded, and the primary winding is short-circuited and connected to the high-voltage shield. The dielectric loss measurement of the end shield in the three methods shows that the measurement results in the method of short-circuiting the primary winding to the high-voltage shielding method are the most accurate. Reference | Related Articles | Metrics

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Test Analysis of Silicone Rubber Aging Detection Based on Microwave Transmission Method LI Huihui, ZHANG Boming, LI Zijin, LI Peng, WU Tian Hunan Electric Power    2023, 43 (2): 14-18.   DOI: 10.3969/j.issn.1008-0198.2023.02.003 Abstract （74）      PDF（pc） （3569KB）（138）       Knowledge map    Save Aiming at the aging problem of shed and sheath of composite insulator, an aging detection method of silicone rubber material based on microwave transmission method is proposed. The artificial accelerated aging test of silicone rubber is carried out, and the microwave nondestructive testing platform is built to carry out the microwave nondestructive testing test of aging silicone rubber. The variation law of transmission parameter S21 of silicone rubber with different aging degrees is analyzed, and the aging detection mechanism of silicone rubber by microwave transmission method was revealed by numerical simulation. The test results show that after the aging of silicone rubber, due to the change of its dielectric properties, the amplitudes of S21 will change,and the aging degree of sillicone rubber can be identified by the value of ΔS21. The research is of great significance to the aging detection of composite insulators. Reference | Related Articles | Metrics

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Prediction of Power Transmission Project Cost Trend Based on Big Data DENG Yiqing, SUN Bin, LI Xiaobing, LI Dan, WANG Rongjing Hunan Electric Power    2023, 43 (2): 108-111.   DOI: 10.3969/j.issn.1008-0198.2023.02.018 Abstract （111）      PDF（pc） （1317KB）（117）       Knowledge map    Save In order to accurately predict the cost of power transmission and transformation projects, control the cost investment in the construction stage, and improve the utilization rate of funds,based on the actual cost data of power transmission and transformation projects in different cities in Shaanxi province, the key influencing factors of power grid project cost are screened by using the entropy weight method, and the BP neural network forecasting model is used to predict the cost of transmission and transformation projects effectively. The forecasting results confirm the validity of the model. Reference | Related Articles | Metrics

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Application of Automatic Voltage Control System Technology Based on Voltage Fluctuation of AC UHV Grid ZHANG Yuanwang , LI Yuqi, ZHANG Shuo, SHI Guoyu , ZHI Xiaochen Hunan Electric Power    2023, 43 (3): 109-114.   DOI: 10.3969/j.issn.1008-0198.2023.03.017 Abstract （102）      PDF（pc） （5217KB）（78）       Knowledge map    Save This paper introduces the principle of voltage fluctuation of UHV power grid and the reactive power control system of UHV power grid. Taking the voltage fluctuation of UHV power grid in East China as the research object, the mainstream AVC control optimization model and the method of building simulation platform are used for analysis. It is verified by application that the strategy can effectively improve the results of AVC assessment by dispatching institutions due to voltage fluctuation of UHV power grid. In engineering application, it provides an effective reference for improving the AVC qualification rate of power plants and reducing the AVC assessment of power plants by dispatching institutions. Reference | Related Articles | Metrics

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Research on Reliability Improvement of Automatic Switching Logic of Station Power Supply System in Converter Station WANG Yingkun, LIU Shunyi, HUANG Chen, LI Qianru, YANG Jiangtao Hunan Electric Power    2022, 42 (4): 90-94.   DOI: 10.3969/j.issn.1008-0198.2022.04.018 Abstract （68）      PDF（pc） （2260KB）（114）       Knowledge map    Save The station power supply system of ±800 kV ultra-high voltage Shaoshan converter station is taken as an example in this paper.The composition of the whole station power supply system and the automatic switching logic of 10 kV and 400V power supply are introduced. In view of the problems existing in the automatic switching logic of 10 kV and 400 V power supply, scientific and reasonable suggestions are introduced to improve the reliability of the DC transmission system. Reference | Related Articles | Metrics

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Research on Improvement Scheme of Frequency Emergency Control for New Power System CHU Xu, XU Liqiang, YAN Yabing, LIU Qi Hunan Electric Power    2022, 42 (4): 13-17.   DOI: 10.3969/j.issn.1008-0198.2022.04.003 Abstract （124）      PDF（pc） （2932KB）（142）       Knowledge map    Save Due to the power characteristics of renewable energy units such as wind power and photovoltaics, and the commutation characteristics of inverter power sources such as DC transmission and photovoltaics, the new power system formed has low inertia and low damping. The system frequency changes quickly and the amplitude is large under the power grid big disturbance scenario. Therefore, it is urgent to study the frequency emergency control improvement scheme suitable for new power systems. Based on the analysis of the frequency characteristics of synchronous machines and inverters, this paper proposes a new power system frequency emergency control improvement scheme that considering distribution network activation, energy storage and renewable energy coordination. The algorithm calculates the real-time power direction of the transmission channel between the active distribution network and the main network, realizes frequency regulation according to the difference of power supply and load attributes, and realizes fast and efficient system frequency emergency control according to the regulation characteristics of energy storage and renewable energy. Reference | Related Articles | Metrics

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Robustness Evaluation of Erection Adjustment of Thrust Bearing for Hydrogenerator WU Hongguang, HU Feng Hunan Electric Power    2022, 42 (4): 85-89.   DOI: 10.3969/j.issn.1008-0198.2022.04.017 Abstract （94）      PDF（pc） （1155KB）（104）       Knowledge map    Save Taking the replacement of an elastic disk-supported thrust bearing as an example, aimed at the deviation in its installation and adjustment, by constructing the coupling equations of the key parameters, such as structural stress, oil film thickness and so on, the robustness of the relevant parameters is solved.It is pointed out that the deviation of lubricant film of thrust bearing is much less than that of structural adjustment in a certain range and it is proportional to the rigidity coefficient of supporting structure. Based on the above analysis, this paper further discusses the basic principles of installation and adjustment of the elastic bearing type thrust bearing, which has reference significance for the installation and adjustment of the various bearing types thrust bearing. Reference | Related Articles | Metrics

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Design and Implementation of Automatic Inspection Tool for Power Optical Transmission System ZENG Xiaohui, CHEN Xiaohui, ZHU Qing, LI Mingjuan, DU Mu′en Hunan Electric Power    2022, 42 (5): 79-84.   DOI: 10.3969/j.issn.1008-0198.2022.05.014 Abstract （98）      PDF（pc） （1820KB）（141）       Knowledge map    Save The optical transmission system is the carrier of the power service channel, and the current post-event passive fault repair operation and maintenance mode is not enough to meet the needs of the operation and maintenance work, while the traditional proactive hidden danger prevention mode is mainly manual periodic inspection, in which the optical path performance inspection needs a lot of manpower. In this paper, the abundant northbound interface of the dedicated network management is used to collect data, design the complete optical section object and the abnormal optical path judgment algorithm, develop the automatic inspection tool of the power optical transmission system, automatically output the inspection results, and give an early warning to the abnormal optical path, so as to find hidden dangers in time to avoid the occurrence of faults and improve the level of independent operation and maintenance. Reference | Related Articles | Metrics

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Influence of Fault Crossing Characteristics of New Energy on Transient Voltage LIU Hui, XIE Wei, GUO Feiyang Hunan Electric Power    2022, 42 (6): 99-103.   DOI: 10.3969/j.issn.1008-0198.2022.06.017 Abstract （96）      PDF（pc） （4739KB）（106）       Knowledge map    Save The weak support and low immunity of the new energy power electronic interface have changed the operating characteristics of the power system, now the fault-through characteristics of conventional photovoltaic power plants have not yet been clearly required by standards, and the actual change characteristics of the dynamic reactive current have little research on the impact of the power grid. Based on the measured data of the fault ride-through test of a photovoltaic power station, a simulation model that can effectively reflect the actual fault-through behavior is established under PSASP, and the influence of the dynamic reactive current change characteristics of the photovoltaic power station under fault conditions on the transient voltage of the power grid is studied.The results show that excessive dynamic reacitve current backregulation cluring fault crossing recovery can cause transient overvoltage after fault recovery. Reference | Related Articles | Metrics

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Non-destructive Identification Method of Transformer Windings Based on Multiple Points Temperature DING Xiaofei, GUO Jing, TANG Haolong Hunan Electric Power    2023, 43 (1): 41-45.   DOI: 10.3969/j.issn.1008-0198.2023.01.007 Abstract （101）      PDF（pc） （4292KB）（162）       Knowledge map    Save To ensure a fair market competition mechanism and avoid aluminum winding transformers from impersonating copper winding transformers, which affects the safety and stability of power system operation, it is important to identify transformer winding materials. To avoid transformer structure damage and identify winding material accurately and effectively, this paper proposes a non-destructive identification method of transformer copper and aluminum winding material based on multiple temperature points, which identifies the winding material based on the resistance coefficient method combining with the results of multiple test points. The experiment results on a copper winding transformer and an aluminum winding transformer show that the proposed method is accurate and effective, and can be further extended to large-scale engineering practice. Reference | Related Articles | Metrics

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Study on Natural Convective Flow Heat Transfer in Supercritical Carbon Dioxide Cavity YE Maojing, WU Tianyu, LIU Kairui, WANG Limin, CHE Defu Hunan Electric Power    2023, 43 (4): 1-8.   DOI: 10.3969/j.issn.1008-0198.2023.04.001 Abstract （86）      PDF（pc） （4176KB）（154）       Knowledge map    Save Horizontal flow of supercritical carbon dioxide (S-CO2) will flow stratification under heating or cooling conditions, resulting in different heat transfer phenomena at the top and bottom of the tube. In order to study the flow heat transfer behavior driven by upward lift in vertical flow direction, the development process of S-CO2 natural convection and the influence of pressure, pipe diameter and temperature interval on the development process are studied based on a two-dimensional circular cavity physical model. The results show that the development process of flow heat transfer away from the pseudo-critical temperature range is relatively stable compared with the pseudo-critical temperature range. In the pseudo-critical temperature range, the higher the pressure, the faster the heat transfer development process. In the pseudo-critical temperature range, the larger the diameter of the pipe, the longer the time for heat transfer to reach stability, and the more intense the main flow zone is in the initial stage of development. Reference | Related Articles | Metrics

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Capacity Optimization Configuration of Grid-Connected Wind-Solar-Hydrogen-Storage Microgrid ZHAO Na, ZHANG Lian, WANG Shibin, LI Duo, HUANG Wei Hunan Electric Power    2023, 43 (4): 48-55.   DOI: 10.3969/j.issn.1008-0198.2023.04.007 Abstract （79）      PDF（pc） （1469KB）（163）       Knowledge map    Save A single type of energy storage device is difficult to take into account the advantages of multiple types of energy storage devices, while the hybrid energy storage system can integrate the technical and economic advantages of different types of energy storage. Aiming at the optimal configuration of hybrid energy storage based on battery and hydrogen energy storage in grid-connected mode, economic and environmental protection are taken as the objective function, the analytic hierarchy process is used to solve the multi-objective weight problem, and the particle swarm optimization algorithm is used to solve the optimal configuration of microgrid capacity. Different energy storage configuration schemes are analyzed and compared by economy and evaluation index. The results show that the cost of hybrid energy storage is 2.46% and 10.02% lower than that of single battery and hydrogen energy storage. The self-balancing rate is 7.65% and 23.89% higher than that of single battery and hydrogen energy storage, and the redundancy is 19% and 38.16% lower than that of single battery and hydrogen energy storage. Reference | Related Articles | Metrics

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Design and Simulation of Power Supply-Traction-Hybrid Energy Storage System for Urban Rail Trains ZHU Zhiqiang, WANG Xin, QIN Bin Hunan Electric Power    2024, 44 (1): 24-31.   DOI: 10.3969/j.issn.1008-0198.2024.01.004 Abstract （65）      PDF（pc） （7016KB）（40）       Knowledge map    Save In order to further improve the recovery and utilization efficiency of urban rail train regenerative braking energy, a structure of urban rail train traction power supply system based on distributed ground hybrid energy storage is designed through the analysis of system functional requirements, and the power supply network, train traction and energy storage system models are established. Moreover, aiming at the problem that low pass filtering leads to a large amount of power exchange between lithium batteries and supercapacitors, a stepped power allocation method with supercapacitor compensation is proposed.This method has small computation and strong real-time performance,and can avoid the internal power circulation of the hybrid energy storage system. Combined with the proposed model and strategy, MATLAB Simulink is used to simulate.The results validate that the energy utilization efficiency of the hybrid energy storage system is improved by 1.39%, the voltage regulation rate is increased by 12.75% and the energy saving rate is increased by 6.72%. Reference | Related Articles | Metrics

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Risk Assessment Model for Load Redistribution Attacks Based on Game Theory YU Mengxi, YAN Yu, ZHOU Zhanfan, DU Min, WANG Lianhong Hunan Electric Power    2024, 44 (2): 1-8.   DOI: 10.3969/j.issn.1008-0198.2024.02.001 Abstract （66）      PDF（pc） （6884KB）（36）       Knowledge map    Save To assess the risk of cyber-attack,this paper constructs a bilayer assessment model of load redistribution attack risk based on game theory,introduces false data attacks and load redistribution attacks,and constructs a two-layer optimisation model for the risk of load redistribution attacks based on a game-theoretic approach.In addition,this paper uses the KKT condition to transform the bilayer model into a single-level mixed-integer linear programming model,and carries out and analyzes simulation experiments on the IEEE 14-bus system and the IEEE 30-bus system,to assess the risk of load redistribution attacks on the security and economic operation of the power system. In addition,this paper provides suggestion on how to prevent and defend against load redistribution attacks. Reference | Related Articles | Metrics

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Research on Automatic Inspection Technology of Relay Protection in Power System CHEN Yuzhi, XU Hao, DONG Yali, SUN Xiaojia, LI Peng, CHEN Zhibiao, BIAN Husai Hunan Electric Power    2022, 42 (4): 95-98.   DOI: 10.3969/j.issn.1008-0198.2022.04.019 Abstract （78）      PDF（pc） （1501KB）（67）       Knowledge map    Save Due to the large area, the distributed and remote substations in Tibet, and the low efficiency in detecting and treating hidden troubles in the secondary system, the relay protection function can not be fully developed. In order to meet the demand of power supply safety in this area, based on the existing fault information processing system, the logic rules and advanced functions are developed, the system software products are developed, and the second professional patrol inspection is upgraded from manual to automatic mode,to ensure the real-time and lean quality of the second round inspection. Reference | Related Articles | Metrics