LOW VOLTAGE APPARATUS

Design of a Pulse Power Device Based on Capacitive Energy Storage

WANG Yubo, LIANG Huimin, WANG Yu, ZHOU Xue, YU Haofu, RUAN Yonggang

2026, 0(6): 1-6. doi:10.16628/j.cnki.2095-8188.2026.06.001

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DC contractors are important components in DC systems. With their wide application in aerospace, new energy, electric vehicles and other fields, the requirements for the breaking voltage and current levels of DC contactors are increasingly stringent. Nevertheless, it is difficult to carry out breaking capacity tests of high-power and high-voltage DC contactors due to the limitation of power supply conditions. To solve this problem, a pulse power generator based on supercapacitor energy storage is designed and developed. A circuit topology of series charging and series discharging is proposed for DC contactor breaking test scenarios. A PLC-based system control module is developed, which integrates and realizes functions including stepless adjustment of output voltage and current, signal acquisition and automatic testing. Test results show that the proposed pulse power equipment can supply high-voltage and large-current experimental conditions (matched with adjustable loads) for DC contactor breaking tests.

Non-Intrusive Charging Monitoring of Electric Bicycles Based on Edge Computing and Color Coding

WANG Zhiqiang, BAO Guanghai, MENG Lixin

2026, 0(6): 7-17. doi:10.16628/j.cnki.2095-8188.2026.06.002

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To reduce fire accidents induced by illegal indoor charging of electric bicycles, non-intrusive load monitoring has become a mainstream research direction for electric bicycle monitoring. Nevertheless, practical application problems of low-cost monitoring terminals remain to be solved urgently. U-I trajectories are constructed with voltage signals and Fourier-filtered current signals, and color coding is implemented for trajectory feature processing. The ShuffleNetV2 neural network is adopted to realize switching detection and identification of illegal indoor charging behavior of electric bicycles. Meanwhile, an on-site charging identification terminal for electric bicycles is developed to resolve engineering application constraints. Experimental results demonstrate that the proposed monitoring equipment can accurately identify illegal indoor charging loads of various electric bicycle brands at the edge computing terminal, with an identification accuracy of 98.75%. It can effectively prevent fire hazards without data transmission dependence, transmission delay, privacy leakage and extra hardware cost.

Analysis on Application Practice of Grid-Forming Energy Storage in Xinjiang Power Grid

Sumaiya·Akpar , Yaxar·Turgun , ZHENG Yunping, ZONG Sijia, XU Shouping

2026, 0(6): 18-27. doi:10.16628/j.cnki.2095-8188.2026.06.003

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The Xinjiang power grid is dominated by a high proportion of renewable energy and exhibits the typical west-to-east power transmission. It faces the dual challenges of long-distance power transmisson and weak-infeed operation. Grid-forming energy storage technology, with its voltage-source characteristics, has become a core supporting technology for addressing Xinjiang’s renewable energy accommodation challenges and ensuring grid security, and it has undergone demonstration validation in the region. Starting from the actual requirements of the power system, the technical features of grid-forming energy storage are described. Using typical application scenarios and demonstration projects in the Xinjiang power grid, it explains the functions that grid-forming energy storage will perform in future power systems. The technical indicators and existing issues related to the grid connection of grid-forming energy storage projects are discussed, and development suggestions are provided, offering practical references for the advancement of this technology.

Research on Harmonic Detection and Active Power Filter Control Based on FFT-Kalman Filter

LU Wenjiang, ZHAO Yun

2026, 0(6): 28-36. doi:10.16628/j.cnki.2095-8188.2026.06.004

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Aiming at the defects of poor real-time performance and low detection accuracy existing in traditional harmonic detection algorithms, a harmonic detection method combining fast Fourier transform (FFT) and Kalman filter is proposed, which is applied to the control system of shunt active power filter (APF). Firstly, the FFT algorithm is used to perform spectrum analysis on current signals and extract the amplitude and phase of each harmonic component. Secondly, the Kalman filter is adopted to dynamically estimate detection data and suppress noise, so as to improve detection precision and anti-interference capability. A double closed-loop control structure combining DC-side voltage PI control and current hysteresis tracking control is adopted in the system. Simulation results indicate that the proposed method can detect grid harmonic currents rapidly and accurately. After compensation, the total harmonic distortion of source current drops from 25.38% to 2.67%, which satisfies the national standard requirements and verifies the validity of the proposed method.

Research on Wide-Area Coordination Planning Technology of Generation-Grid-Storage for the Novel Power System Towards Multi-Regional Peak Shaving and Mutual Power Support

LI Zirun, GENG Lin, HUANG Dengyi, XIAO Weidong, SHI Peiran

2026, 0(6): 37-51. doi:10.16628/j.cnki.2095-8188.2026.06.005

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With the large-scale integration of renewable energy and increasingly prominent inter-regional power demand differences, existing planning methods are mostly limited to single regions or local generation-grid-storage coordination, which cannot meet the requirements of cross-regional power complementation and wide-area coordinated operation. Aiming at the wide-area coordinated planning difficulty of generation-grid-storage oriented to multi-regional power peak shaving and mutual power support, a novel planning framework integrating multi-temporal-spatial scale coupled modeling, cross-regional complementary characteristic mining and collaborative optimization mechanism is proposed. Firstly, a multi-regional joint generation-grid-storage model considering climatic differences and time-series load characteristics is established. The Copula theory is adopted to generate wind-solar joint output scenario sets and quantitatively quantify the time-series peak shaving potential of each region. Secondly, a wide-area coordinated planning model with the objective of minimizing total system cost is built to realize coordinated allocation of power sources, power grids and energy storage facilities. Finally, a robust-stochastic hybrid optimization method is introduced to cope with multiple uncertainties of renewable energy output and cross-regional transmission capacity. Taking the interconnected multi-regional power grids of China's Three-North Region and East China as the example, simulation verification is carried out. The results show that after optimal planning, the proportion of renewable energy power generation of the system rises to 93.1%, among which wind and photovoltaic power account for 69.3% of total power generation. The overall system cost is reduced by 8.5%, and the cross-regional mutual power support capacity is increased by approximately 15.0%. The research provides theoretical support and technical approaches for realizing low-carbon, high-efficiency and secure coordinated development of multi-regional power systems.

Simulation Study on Arc Extinguishing Performance Improvement of 1 500 V DC Molded Case Circuit Breaker with Folded Arc Extinguishing Chamber

CHEN Xiongchu, LI Jing, WU Qijun

2026, 0(6): 52-58. doi:10.16628/j.cnki.2095-8188.2026.06.006

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Aiming at the significant influence of air duct parameters on the arc extinguishing performance of the folded arc extinguishing chamber for 1 500 V DC molded case circuit breakers, multi-parameter design of the air duct structure and multi-objective optimization of its arc extinguishing performance are performed. Taking the arc voltage rise time and peak voltage as optimization objectives, simulation analysis of the folded arc extinguishing chamber is carried out using the orthogonal test method. The optimization results show that compared with the original scheme, increasing the bending angle of the arc guide bridge, reducing the number of grid plates, increasing the number of exhaust holes, and enlarging the distance between the grid plate group and the gas baffle are conducive to accelerating arc transfer and increasing the arc voltage; after optimization, the voltage rise time of the circuit breaker is shortened by 22.7%, the peak voltage is increased by 10.7%, and the overall arc extinguishing performance is significantly enhanced. A reference is provided for the design of arc extinguishing chambers in high-voltage DC molded case circuit breakers.

Simulation and Analysis of Guide Clearance Effects on Unbalanced Arcing Characteristics in Bridge-Type Contact During Breaking

HUANG Jinglong, WEI Feng, DENG Chuanchuan, LIU Xiangjun

2026, 0(6): 59-66. doi:10.16628/j.cnki.2095-8188.2026.06.007

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The guide clearance between the hole of the static iron core and the guide rod is the key parameter affecting the movement of the contact bridge of the direct-acting double-break electrical apparatus. To investigate its influence on the arcing characteristics, multi-body dynamics simulation software is adopted to analyze the motion characteristics of the contact bridge under different guide clearances, a three-dimensional arc magnetohydrodynamics model is established to investigate the influence of the guide clearance on the arcing characteristics of the bridge contact. Through the research on a type of double breakpoint high-power DC relay, it is found that reducing the guide clearance can effectively suppress the unbalanced breaking of the contact bridge and the contact breaking jitter, reduce the breaking speed difference between the two contacts, and significantly reduce the arc energy difference between them. When the clearance is reduced to 0.3 mm, the contact approaches a balanced breaking state, and the arc energy difference between the two sides of the contact is only 0.042 J, which is 86.5% less than that when the clearance is 1.0 mm. Taking both performance and manufacturing requirements into consideration, the guide clearance of 0.3 mm is selected as the optimal solution, which helps to improve the breaking balance and arcing balance of the relay.

Research on Arc Extinguishing Characteristics of DC Molded Case Circuit Breaker Based on Arc Voltage

ZHANG Senlin, ZHANG Yihe, WANG Bingqing

2026, 0(6): 67-75. doi:10.16628/j.cnki.2095-8188.2026.06.008

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The short-circuit arc extinguishing conditions of low-voltage DC molded case circuit breakers remain unclear, and no quantitative evaluation criterion is available for the breaking performance of products equipped with different arc extinguishing chamber structures. To solve this problem, an evaluation method for short-circuit breaking performance of DC molded case circuit breakers based on arc voltage is proposed. Different target arc voltages are obtained by adjusting the quantity of arc plates inside the arc extinguishing chamber. It systematically studies the influence of average arc voltage on the arc extinguishing performance of circuit breakers under three test conditions: 1 500 V/5 kA, 750 V/20 kA and 750 V/10 kA. Test results indicate that the critical average arc voltage coefficients for reliable arc extinction under the three working conditions are 0.45, 1.13 and 0.89, and the corresponding required numbers of arc plates for the arc extinguishing chamber are 30, 34 and 30 respectively. The research conclusions can offer theoretical guidance for the design and optimization of arc extinguishing chambers of low-voltage DC molded case circuit breakers, and support rapid screening of the optimal matching scheme for arc extinguishing chamber layout.

Research on High-Voltage Direct Current Disconnectors

WANG Yue, ZHONG Yunpan

2026, 0(6): 76-83. doi:10.16628/j.cnki.2095-8188.2026.06.009

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With the rapid expansion of the photovoltaic energy storage industry, energy storage systems are developing toward high voltage, large capacity and high current. Traditional disconnectors cannot adapt to the high-voltage and high-current operating conditions of energy storage systems, and are plagued by insufficient making-breaking performance and poor short-time withstand capacity. A high-voltage DC high-current disconnector is proposed. Systematic optimization design is conducted from four dimensions: overall product structure, making-breaking characteristics, short-time withstand performance and operating mechanism design. Performance verification is realized through simulation calculation and physical tests. Test results show that the developed disconnector can adapt to the harsh high-voltage and high-current working conditions of energy storage systems and possesses outstanding comprehensive performance. The proposed product design scheme can provide design ideas and technical references for developing large-capacity disconnectors applied to photovoltaic energy storage systems.

Research on Dynamic Reactive Power Compensation Optimization of SVC in Thermal Power Plants Based on Improved DRL Model

ZHENG Kai

2026, 0(6): 84-88. doi:10.16628/j.cnki.2095-8188.2026.06.010

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When optimizing reactive power compensation of static var compensator (SVC) in thermal power plants, taking the internal active power demand of SVC as the threshold will cause deviation of voltage safety margin and aggravate voltage amplitude fluctuation, thereby deteriorating the compensation performance. Accordingly, an optimization method for dynamic reactive power compensation of SVC in thermal power plants based on an improved deep reinforcement learning (DRL) model is proposed. The DRL model is improved with the Dueling architecture, and the Dueling network structure is adopted to evaluate state values more accurately so as to raise the safety margin of the access voltage of SVC. The minimization of voltage deviation is taken as the objective function to calculate the optimal voltage amplitude for dynamic reactive power compensation of SVC in thermal power plants and realize optimized dynamic reactive power regulation. Experimental results demonstrate that the optimized voltage amplitude fluctuates between 0.97~1.00 p.u. with slight fluctuation and favorable compensation performance, which is of great significance for guaranteeing the stable operation of thermal power plant equipment.

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