Pub Date : 2024-06-01DOI: 10.23919/CJEE.2024.000053
Lizhen Wu;Heng Yang;Jianping Wei;Wendong Jiang
Microgrids are networked control systems with multiple distributed generators (DGs). Microgrids are associated with many problems, such as communication delays, high sampling rates, and frequent controller updates, which make it challenging to realize coordination control among the DGs. Therefore, finite-time consensus algorithms and event-triggered control methods are combined to propose a distributed coordination control method for microgrid systems. The DG in the microgrid system serves as an agent node in the control network, and a distributed secondary controller is designed using finite-time consensus algorithm, such that the frequency and voltage restoration control has a faster convergence time and better anti-interference performance. The event-triggered function was designed based on the state information of the agents. The controller exchanges the state information at the trigger instants. System stability is analyzed using the Lyapunov stability theory, and it is verified that the controller cannot exhibit the Zeno phenomenon in the event-triggered process. A simulation platform was developed in Matlab/Simulink to verify that the proposed control method can effectively reduce the frequency of controller updates during communication delays and the burden on the communication network.
{"title":"Research on Distributed Coordination Control Method for Microgrid System Based on Finite-Time Event-Triggered Consensus Algorithm","authors":"Lizhen Wu;Heng Yang;Jianping Wei;Wendong Jiang","doi":"10.23919/CJEE.2024.000053","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000053","url":null,"abstract":"Microgrids are networked control systems with multiple distributed generators (DGs). Microgrids are associated with many problems, such as communication delays, high sampling rates, and frequent controller updates, which make it challenging to realize coordination control among the DGs. Therefore, finite-time consensus algorithms and event-triggered control methods are combined to propose a distributed coordination control method for microgrid systems. The DG in the microgrid system serves as an agent node in the control network, and a distributed secondary controller is designed using finite-time consensus algorithm, such that the frequency and voltage restoration control has a faster convergence time and better anti-interference performance. The event-triggered function was designed based on the state information of the agents. The controller exchanges the state information at the trigger instants. System stability is analyzed using the Lyapunov stability theory, and it is verified that the controller cannot exhibit the Zeno phenomenon in the event-triggered process. A simulation platform was developed in Matlab/Simulink to verify that the proposed control method can effectively reduce the frequency of controller updates during communication delays and the burden on the communication network.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"10 2","pages":"103-115"},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10586887","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141543849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-28DOI: 10.23919/CJEE.2024.000069
Xizhe Wang;Longnv Li;Shengyang Hu;Gaojia Zhu
With the rapid growth of capacity in power systems, transformer failure caused by short circuits has become the primary problem in maintaining operational reliability. In addition, with automatic reclosing, transformers may suffer multiple short-circuit impacts within a short time interval, thereby challenging their short-circuit stability. In this study, a comprehensive analysis of the radial strength under reclosing short-circuit conditions is performed on a 50 MV • A transformer considering the influence of temperature. First, a fault model of the power transformer is established to calculate the short-circuit currents under the initial short circuit and reclosing conditions. Three-dimensional (3D) finite element analyses of the short-circuit forces acting on the transformer winding with the initial and reclosing short circuits are then conducted. Finally, the influence of temperature on the windings after reclosing is calculated. The stress characteristics of the windings are calculated by considering the effects of temperature on the self-adhesive transposition wire.
{"title":"Radial-Strength of Transformer Windings Considering the Temperature Effect under Reclosing Short-circuit Conditions","authors":"Xizhe Wang;Longnv Li;Shengyang Hu;Gaojia Zhu","doi":"10.23919/CJEE.2024.000069","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000069","url":null,"abstract":"With the rapid growth of capacity in power systems, transformer failure caused by short circuits has become the primary problem in maintaining operational reliability. In addition, with automatic reclosing, transformers may suffer multiple short-circuit impacts within a short time interval, thereby challenging their short-circuit stability. In this study, a comprehensive analysis of the radial strength under reclosing short-circuit conditions is performed on a 50 MV • A transformer considering the influence of temperature. First, a fault model of the power transformer is established to calculate the short-circuit currents under the initial short circuit and reclosing conditions. Three-dimensional (3D) finite element analyses of the short-circuit forces acting on the transformer winding with the initial and reclosing short circuits are then conducted. Finally, the influence of temperature on the windings after reclosing is calculated. The stress characteristics of the windings are calculated by considering the effects of temperature on the self-adhesive transposition wire.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"11 4","pages":"219-226"},"PeriodicalIF":3.5,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10540366","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-28DOI: 10.23919/CJEE.2024.000071
Jun Li;Mingdi Miao
For short-term wind power forecasting, an interval A2-C1 type-2 (IT2) Takagi-Sugeno-Kang (TSK) fuzzy logic system (FLS) method (“A” means antecedent and “C” consequent) based on an extended Kalman filter (EKF) optimization algorithm is proposed. Compared with the type-1 (T1) FLS model, the IT2 TSK FLS method can simultaneously model both intra- and inter-individual uncertainty and further optimize the antecedent and consequent parameters using the EKF to improve forecasting performance further. The proposed IT2 A2-C1 FLS method is applied to Mackey-Glass chaotic time series and wind power forecasting instances in a certain region, under the same conditions. It is also compared with the T1 TSK FLS and IT2 TSK FLS methods with back propagation (BP) and particle swarm optimization (PSO) algorithms, as well as IT2 A2-C0 TSK FLS methods with EKF. The experimental results confirm that the proposed IT2 A2-C1 FLS method is superior to the other FLS methods regarding performance, which demonstrates its effectiveness and application potential.
{"title":"Short-Term Wind Power Forecasting Using Interval A2-C1 Type-2 TSK FLS Method with Extended Kalman Filter Algorithm","authors":"Jun Li;Mingdi Miao","doi":"10.23919/CJEE.2024.000071","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000071","url":null,"abstract":"For short-term wind power forecasting, an interval A2-C1 type-2 (IT2) Takagi-Sugeno-Kang (TSK) fuzzy logic system (FLS) method (“A” means antecedent and “C” consequent) based on an extended Kalman filter (EKF) optimization algorithm is proposed. Compared with the type-1 (T1) FLS model, the IT2 TSK FLS method can simultaneously model both intra- and inter-individual uncertainty and further optimize the antecedent and consequent parameters using the EKF to improve forecasting performance further. The proposed IT2 A2-C1 FLS method is applied to Mackey-Glass chaotic time series and wind power forecasting instances in a certain region, under the same conditions. It is also compared with the T1 TSK FLS and IT2 TSK FLS methods with back propagation (BP) and particle swarm optimization (PSO) algorithms, as well as IT2 A2-C0 TSK FLS methods with EKF. The experimental results confirm that the proposed IT2 A2-C1 FLS method is superior to the other FLS methods regarding performance, which demonstrates its effectiveness and application potential.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"11 3","pages":"191-215"},"PeriodicalIF":3.5,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10540368","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145352209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-28DOI: 10.23919/CJEE.2024.000062
Yabing Yan;Fei Ao;Huilin Liu;Biao Xu;Jinbo Wu;Hui Li;Yong Li;Sijia Hu
The existing current break protection cannot achieve full-line current protection and may lose its protection capability. Therefore, a self-adjusted full-line current protection strategy based on a double-layer criterion is proposed. The first layer of the criterion adopts the adaptive adjustment threshold as the setting value to realize full-line fault monitoring, which is not affected by the system operation mode and fault type. The second layer is used to locate the fault section of the line and improve the selectivity of the protection strategy. Considering the difficulty in accurately identifying high-resistance ground faults using current protection, an identification method based on compound power is proposed by analyzing the zero-sequence network of the system. Simulation results show that the proposed protection strategy can realize full-length line protection and the effective identification of high-resistance ground faults and is not affected by the system load variation and fault type.
{"title":"Novel Self-adjusted Full-line Current Protection Strategy for Small Resistance Grounding Distribution Network","authors":"Yabing Yan;Fei Ao;Huilin Liu;Biao Xu;Jinbo Wu;Hui Li;Yong Li;Sijia Hu","doi":"10.23919/CJEE.2024.000062","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000062","url":null,"abstract":"The existing current break protection cannot achieve full-line current protection and may lose its protection capability. Therefore, a self-adjusted full-line current protection strategy based on a double-layer criterion is proposed. The first layer of the criterion adopts the adaptive adjustment threshold as the setting value to realize full-line fault monitoring, which is not affected by the system operation mode and fault type. The second layer is used to locate the fault section of the line and improve the selectivity of the protection strategy. Considering the difficulty in accurately identifying high-resistance ground faults using current protection, an identification method based on compound power is proposed by analyzing the zero-sequence network of the system. Simulation results show that the proposed protection strategy can realize full-length line protection and the effective identification of high-resistance ground faults and is not affected by the system load variation and fault type.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"10 4","pages":"83-96"},"PeriodicalIF":0.0,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10540367","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142918578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study examines the impact of circulating currents on copper loss in alternating current systems and introduces a method to reduce these losses. Initially, a circuit model for the winding is developed to analyze the magnetic leakage field in the stator slot. Subsequently, an equivalent model based on this magnetic leakage field is constructed to assess the magnetic linkage of the strand as the conductor's position within the slot varies. Comparisons of circulating currents in two different winding configurations are presented. Based on these analyses, a specific winding arrangement designed to reduce circulating current losses is proposed. The effectiveness of this design is then corroborated through experimental validation.
{"title":"Analyzing and Suppressing of Circulating Current Loss in High-Speed Permanent Magnet Motors","authors":"Yuxi Wang;Jinghua Ji;Jie Li;Tong Liu;Wenxiang Zhao","doi":"10.23919/CJEE.2024.000070","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000070","url":null,"abstract":"This study examines the impact of circulating currents on copper loss in alternating current systems and introduces a method to reduce these losses. Initially, a circuit model for the winding is developed to analyze the magnetic leakage field in the stator slot. Subsequently, an equivalent model based on this magnetic leakage field is constructed to assess the magnetic linkage of the strand as the conductor's position within the slot varies. Comparisons of circulating currents in two different winding configurations are presented. Based on these analyses, a specific winding arrangement designed to reduce circulating current losses is proposed. The effectiveness of this design is then corroborated through experimental validation.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"11 4","pages":"151-162"},"PeriodicalIF":3.5,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10540373","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-28DOI: 10.23919/CJEE.2024.000072
Meng Shao;Qianfan Zhang;Zhen Wei;Hanlin Li
The integrated on-board battery chargers (IOBCs) can be used to repurpose the existing high-rated power electronic devices in electric vehicles (EVs) for charging, thereby cutting costs. However, non-isolated IOBCs face significant common-mode (CM) leakage currents owing to the lack of current isolation and coupling between the AC and DC side CM filters. A method that combines topology and modulation to suppress the CM leakage currents in a non-isolated integrated charger is proposed. The touch current can be suppressed below a reaction threshold of 1 MIU. This enhancement enables the safe usage and commercialization of transformer-less chargers, presenting superior charger efficiency, power density, and cost-effectiveness. The CM model of the proposed system is derived to guide the design of the circuit topology and modulation schemes. The simulation results are used to determine the feasibility of these techniques. Finally, a prototype of the 6.6 kW experimental charger is proposed, and the experimental results demonstrate the effectiveness of the proposed solution.
{"title":"A Method for Suppressing Leakage Current of Non-isolated Integrated On-board EV Battery Charger","authors":"Meng Shao;Qianfan Zhang;Zhen Wei;Hanlin Li","doi":"10.23919/CJEE.2024.000072","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000072","url":null,"abstract":"The integrated on-board battery chargers (IOBCs) can be used to repurpose the existing high-rated power electronic devices in electric vehicles (EVs) for charging, thereby cutting costs. However, non-isolated IOBCs face significant common-mode (CM) leakage currents owing to the lack of current isolation and coupling between the AC and DC side CM filters. A method that combines topology and modulation to suppress the CM leakage currents in a non-isolated integrated charger is proposed. The touch current can be suppressed below a reaction threshold of 1 MIU. This enhancement enables the safe usage and commercialization of transformer-less chargers, presenting superior charger efficiency, power density, and cost-effectiveness. The CM model of the proposed system is derived to guide the design of the circuit topology and modulation schemes. The simulation results are used to determine the feasibility of these techniques. Finally, a prototype of the 6.6 kW experimental charger is proposed, and the experimental results demonstrate the effectiveness of the proposed solution.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"10 4","pages":"47-59"},"PeriodicalIF":0.0,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10540372","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142918516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-28DOI: 10.23919/CJEE.2024.000050
Guangjing Su;Hongmei Li;Zheng Li;Yanan Zhou
A model-free control (MFC) method is proposed to improve the dynamic response performance of permanent magnet synchronous linear motors (PMSLMs) and reduce motor parameter changes during motor operation. The MFC is established based on an ultra-local model that uses only the input and output of the system without using any PMSLM parameters. Compared with the conventional proportional-integral (PI) control method, the robustness of the MFC system is superior and can counteract the effects of changing motor parameters and external disturbances. Simulations and experiments are conducted with steady-state operation, sudden addition and subtraction of loads, and motor parameter perturbations. The results confirm that the proposed method is useful and robust to uncertainties in motor parameters and helps improve the dynamic performance of the PMSLM.
{"title":"Model-Free Control of Permanent Magnet Synchronous Linear Motor Based on Ultra-local Model","authors":"Guangjing Su;Hongmei Li;Zheng Li;Yanan Zhou","doi":"10.23919/CJEE.2024.000050","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000050","url":null,"abstract":"A model-free control (MFC) method is proposed to improve the dynamic response performance of permanent magnet synchronous linear motors (PMSLMs) and reduce motor parameter changes during motor operation. The MFC is established based on an ultra-local model that uses only the input and output of the system without using any PMSLM parameters. Compared with the conventional proportional-integral (PI) control method, the robustness of the MFC system is superior and can counteract the effects of changing motor parameters and external disturbances. Simulations and experiments are conducted with steady-state operation, sudden addition and subtraction of loads, and motor parameter perturbations. The results confirm that the proposed method is useful and robust to uncertainties in motor parameters and helps improve the dynamic performance of the PMSLM.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"10 4","pages":"73-82"},"PeriodicalIF":0.0,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10540369","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142918237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-28DOI: 10.23919/CJEE.2024.000056
Peijin Liu;Tao Huang;Haojian Ding;Lei Dong;Jie Li
In order to further improve the tracking accuracy, speed, and disturbance robustness of the global maximum power point tracking (GMPPT) control of a photovoltaic array under partial-shade conditions, a photovoltaic GMPPT control method based on the improved dung beetle optimization (IDBO) algorithm is proposed. First, in order to improve the algorithm performance, a Chebyshev chaotic map is used to initialize the positions of the dung beetles to make the distribution of the dung beetle population in the search space more uniform, which increased the population convergence rate and final solution accuracy of the algorithm. Second, a neighborhood search mechanism combined with a Levy flight strategy is introduced to enhance the local search precision and convergence speed of the algorithm, and improve the accuracy of the global maximum power point (GMPP) location. At the same time, a dynamic weight is introduced to improve the convergence rate of the algorithm in the later search stage, along with the global-search ability of the equalization algorithm. Finally, a restart mechanism is used to enhance the robustness of the GMPPT control through the influence of mutation factors in a complex environment. The experimental results show that compared with DBO, grey wolf optimization (GWO), sparrow search algorithm (SSA) and particle swarm optimization (PSO) algorithms, the IDBO based solar maximum power point tracking control method is more accurate in determining the GMPP position, and has better dynamic response speed and tracking accuracy.
{"title":"Photovoltaic GMPPT Control Method under Local Shade Based on Improved DBO","authors":"Peijin Liu;Tao Huang;Haojian Ding;Lei Dong;Jie Li","doi":"10.23919/CJEE.2024.000056","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000056","url":null,"abstract":"In order to further improve the tracking accuracy, speed, and disturbance robustness of the global maximum power point tracking (GMPPT) control of a photovoltaic array under partial-shade conditions, a photovoltaic GMPPT control method based on the improved dung beetle optimization (IDBO) algorithm is proposed. First, in order to improve the algorithm performance, a Chebyshev chaotic map is used to initialize the positions of the dung beetles to make the distribution of the dung beetle population in the search space more uniform, which increased the population convergence rate and final solution accuracy of the algorithm. Second, a neighborhood search mechanism combined with a Levy flight strategy is introduced to enhance the local search precision and convergence speed of the algorithm, and improve the accuracy of the global maximum power point (GMPP) location. At the same time, a dynamic weight is introduced to improve the convergence rate of the algorithm in the later search stage, along with the global-search ability of the equalization algorithm. Finally, a restart mechanism is used to enhance the robustness of the GMPPT control through the influence of mutation factors in a complex environment. The experimental results show that compared with DBO, grey wolf optimization (GWO), sparrow search algorithm (SSA) and particle swarm optimization (PSO) algorithms, the IDBO based solar maximum power point tracking control method is more accurate in determining the GMPP position, and has better dynamic response speed and tracking accuracy.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"11 4","pages":"243-257"},"PeriodicalIF":3.5,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10540371","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Renewable energy has become important for electricity generation because of the high air pollution associated with conventional fossil-based energy systems. Conventional fossil-based power plants are gradually transitioning by incorporating renewable energy sources, such as photovoltaic (PV) cells. In a PV system, an inverter converts DC power from solar panels to AC power required to serve common electrical loads. A conventional H-bridge inverter topology has several disadvantages, such as the voltage being not sinusoidal, switching the DC voltage and high common-mode voltage. The common-mode voltage can cause a large leaked capacitive current, which can result in undesirable operation in solar power applications. A common solution to this problem is the addition of a large filter to the input or output of an inverter. An inherent sinusoidal voltage source inverter based on a modified Cuk converter as its basic cell, which simultaneously generates a sinusoidal output voltage and a lower common-mode voltage, is proposed. The proposed topology does not require additional input or output filters. Analytical expressions are derived to confirm the operation of the proposed topology. Simulation results confirm the mathematical analysis. A laboratory-scale experiment is performed to verify the proposed inverter.
由于传统的化石能源系统会造成严重的空气污染，因此可再生能源在发电方面变得非常重要。传统的化石能源发电厂正在逐步转型，采用可再生能源，如光伏（PV）电池。在光伏系统中，逆变器将太阳能电池板发出的直流电转换为普通电力负载所需的交流电。传统的 H 桥逆变器拓扑结构有几个缺点，如电压不是正弦波、直流电压开关和共模电压过高。共模电压会产生较大的泄漏电容电流，从而导致太阳能发电应用中的不良运行。解决这一问题的常见方法是在逆变器的输入或输出端增加一个大型滤波器。本文提出了一种以改进型 Cuk 转换器为基本单元的固有正弦电压源逆变器，它能同时产生正弦输出电压和较低的共模电压。所提出的拓扑结构不需要额外的输入或输出滤波器。分析表达式的推导证实了拟议拓扑结构的运行。仿真结果证实了数学分析。为验证所提出的逆变器，还进行了实验室规模的实验。
{"title":"Inherently Sinusoidal Single-Phase Voltage Source Inverter Based on Modified Cuk Cell","authors":"Misbahul Munir;Wisyahyadi;Arwindra Rizqiawan;Jihad Furqani","doi":"10.23919/CJEE.2024.000051","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000051","url":null,"abstract":"Renewable energy has become important for electricity generation because of the high air pollution associated with conventional fossil-based energy systems. Conventional fossil-based power plants are gradually transitioning by incorporating renewable energy sources, such as photovoltaic (PV) cells. In a PV system, an inverter converts DC power from solar panels to AC power required to serve common electrical loads. A conventional H-bridge inverter topology has several disadvantages, such as the voltage being not sinusoidal, switching the DC voltage and high common-mode voltage. The common-mode voltage can cause a large leaked capacitive current, which can result in undesirable operation in solar power applications. A common solution to this problem is the addition of a large filter to the input or output of an inverter. An inherent sinusoidal voltage source inverter based on a modified Cuk converter as its basic cell, which simultaneously generates a sinusoidal output voltage and a lower common-mode voltage, is proposed. The proposed topology does not require additional input or output filters. Analytical expressions are derived to confirm the operation of the proposed topology. Simulation results confirm the mathematical analysis. A laboratory-scale experiment is performed to verify the proposed inverter.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"10 1","pages":"114-123"},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10490168","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140345495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-01DOI: 10.23919/CJEE.2023.000044
Zongying Li;Shuaibing Li;Yongqiang Kang;Zheng Li;Hongwei Li
With the growing demand for precise voltage adjustment and reactive regulation, the frequent operation of on-load tap changers (OLTCs) in oil-immersed systems has led to increased erosion of switch contacts by arcs during the switching process. This erosion causes significant wear on the contacts, thereby reducing their lifespan. Therefore, the present study aims to investigate the behavior and mechanism of arc erosion on contact surfaces in oil-immersed OLTCs. To achieve this, a self-designed friction and wear test device for OLTC contacts was utilized to conduct experiments at various sliding speeds and contact pressures. Additionally, finite element analysis was employed to validate the experimental results regarding the influence of sliding speed on arc energy. The surface morphology of the contacts was observed using an optical microscope. The findings revealed that as the sliding speed increased, the arc energy, arc initiation rate, and contact resistance initially exhibited an upward trend, then decreased, and eventually increased again. The minimum values were observed at a sliding speed of 90 mm/s. Moreover, the arc energy, arc initiation rate, and contact resistance decreased gradually as the contact pressure increased. After reaching a contact pressure of 1.5 N, the variation in the arc energy stabilized. At lower contact pressures, arc erosion dominated the wear on the contact surface. However, at higher contact pressures, the wear transitioned from predominantly arc erosion to a combination of mechanical wear and arc erosion. In summary, experimental and analytical investigations provided insights into the effects of sliding speed and contact pressure on the behavior of arc erosion, contact resistance, and surface damage of OLTC contacts in oil-immersed systems.
随着对精确电压调节和无功调节的需求日益增长，油浸式系统中的有载分接开关（OLTC）频繁运行，导致开关触头在切换过程中受到电弧的侵蚀日益严重。这种侵蚀会导致触头严重磨损，从而缩短其使用寿命。因此，本研究旨在调查油浸式有载分接开关中电弧对触点表面侵蚀的行为和机理。为此，我们利用自行设计的有载分接开关触头摩擦和磨损测试装置，在各种滑动速度和接触压力下进行了实验。此外，还利用有限元分析验证了滑动速度对电弧能量影响的实验结果。使用光学显微镜观察了触头的表面形态。研究结果表明，随着滑动速度的增加，电弧能、起弧率和接触电阻最初呈上升趋势，然后下降，最后再次上升。在滑动速度为 90 mm/s 时观察到最小值。此外，电弧能、起弧率和接触电阻随着接触压力的增加而逐渐减小。接触压力达到 1.5 N 后，电弧能量的变化趋于稳定。在较低的接触压力下，电弧侵蚀主导着接触表面的磨损。然而，在较高的接触压力下，磨损从主要的电弧侵蚀过渡到机械磨损和电弧侵蚀的结合。总之，实验和分析研究深入揭示了滑动速度和接触压力对油浸系统中 OLTC 触头的电弧侵蚀、接触电阻和表面损坏行为的影响。
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