Protection Characteristics Analysis and Robustness Design of Electromagnetic Residual Current Device
Li Kui1, Yu Minghao1, Niu Feng1, Wu Yi2, Lu Zhiwei2
1. State Key Laboratory of Reliability and Intelligence of Electrical Equipment Hebei University of Technology Tianjin 300401 China; 2. Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province Hebei University of Technology Tianjin 300401 China
Abstract：Residual current devices (RCDs) are critical electrical safety devices that can quickly cut off the power supply when leakage faults occur in power lines or electrical equipment, thus preventing electrical fires and ensuring personal safety. Among them, electromagnetic RCDs are highly valued due to their stable leakage protection characteristics, excellent anti-interference capability, and rapid response time. This paper focuses on the series-parallel compensation capacitor in the leakage protection driving circuit of fast-acting electromagnetic RCDs and the robustness of leakage protection characteristics. The matching relationship between the series- parallel compensation capacitor and residual current transformer (RCT) is determined, and relevant parameters are optimized to enhance the robustness of electromagnetic leakage protection characteristics. The main research work and conclusions are as follows. (1) The main components of electromagnetic RCD are analyzed. The transmission characteristics of RCT are affected by the excitation characteristics of the iron core and the driving circuit. The key factor for the reliable operation of the magnetic release is the excitation of ampere-turns, and the topology of the driving circuit determines the leakage protection characteristics. The working principle of the compensation circuit with a series-parallel capacitor is analyzed, and the relationship between circuit characteristics and element parameters is studied. (2) The topology of the leakage driving circuit with a series-parallel compensation capacitor is investigated. The influence of compensation capacitors and RCT on leakage protection characteristics is explored. The matching principle of compensation capacitors and their relationship with leakage protection value are studied, and the variation characteristics of the capacitor matching curve under different protection values are determined. It is suggested that the exciting inductance of RCT should be designed to be greater than the critical inductance to reduce the influence of compensation capacitor dispersion on the leakage protection value. The impact of magnetic parameters of RCT on leakage protection characteristics is studied, and the influence of hysteresis and magnetic saturation characteristics on the matching principle of compensation capacitors is analyzed. The increase in saturation magnetic flux density Bs and remanence Br leads to a decrease in protection value. In contrast, the increase in coercive force Hc leads to an increase. (3) The dispersion influence of compensation capacitors and RCT magnetic parameter on leakage protection characteristics is studied. The range of the compensation capacitor is determined through sensitivity analysis. Saturation magnetic flux density Bs shows the least influence on protection value, coercive force Hc shows the second least influence, and remanence Br shows the most significant influence. When the compensation capacitor is on the left side of the knee point of the right half of the matching curve, the leakage protection value is the least affected by the dispersion of magnetic parameters. A comprehensive design method for RCT and compensation capacitors is proposed, and the optimal design scheme is determined by an orthogonal method. Under the same component parameter fluctuation, the fluctuation range of leakage protection value is reduced by 46.04% after parameter optimization, enhancing the robustness of leakage protection characteristics.
[1] 孙荣可, 单玉凯, 薛永端, 等. 基于负荷电流闭锁的低压配电网漏电保护[J]. 电力系统及其自动化学报, 2023, 35(3): 21-28. Sun Rongke, Shan Yukai, Xue Yongduan, et al.Leakage protection for low-voltage distribution network based on load current locking[J]. Proceedings of the CSU-EPSA, 2023, 35(3): 21-28. [2] 高伟, 饶俊民, 全圣鑫, 等. 不均衡小样本下多特征优化选择的生命体触电故障识别方法[J]. 电工技术学报, 2024, 39(7): 2060-2071. Gao Wei, Rao Junmin, Quan Shengxin, et al.Biological electric-shock fault identification method based on multi-feature optimization selection under unbalanced small sample[J]. Transactions of China Electrotechnical Society, 2024, 39(7): 2060-2071. [3] Zhang Mingming, Qin Ping, Chen Yongjin, et al.Study on the detection method of leakage in TN-C area of low-voltage distribution network[C]//2021 International Conference on Power System Tech- nology (POWERCON), Haikou, China, 2021: 378-381. [4] 李奎, 郝运佥, 赵成晨, 等. 基于马尔可夫过程的漏电保护器服役状态及其可靠性分析[J]. 电工技术学报, 2023, 38(18): 5061-5076. Li Kui, Hao Yunqian, Zhao Chengchen, et al.Service states and reliability analysis of residual current device based on Markov process[J]. Transactions of China Electrotechnical Society, 2023, 38(18): 5061-5076. [5] Li Kui, Lin Jingyi, Niu Feng, et al.A novel fault leakage current detection method with protection deadzone elimination[J]. IEEE Transactions on Instru- mentation and Measurement, 2020, 70: 3505009. [6] 沈泽亮, 汪金刚, 王谦, 等. 一种基于低频窄带扫描的电磁式电压互感器杂散电容测量与精确建模方法[J]. 电工技术学报, 2023, 38(8): 2211-2221. Shen Zeliang, Wang Jingang, Wang Qian, et al.A method for stray capacitance measuring and refined modeling of potential transformer based on low frequency and narrow band scanning[J]. Transactions of China Electrotechnical Society, 2023, 38(8): 2211-2221. [7] 刘帼巾, 李想, 王泽, 等. 基于Wiener过程电子式漏电断路器的剩余寿命预测[J]. 电工技术学报, 2022, 37(2): 528-536. Liu Guojin, Li Xiang, Wang Ze, et al.Remaining life prediction of electronic residual current circuit breaker based on Wiener process[J]. Transactions of China Electrotechnical Society, 2022, 37(2): 528-536. [8] 刘帼巾, 王泽, 李想, 等. 基于改进Bootstrap- Bayes的电子式剩余电流动作断路器可靠性评估[J]. 电工技术学报, 2022, 37(16): 4250-4258. Liu Guojin, Wang Ze, Li Xiang, et al.Reliability evaluation of electronic residual current operated circuit breakers based on improved Bootstrap- Bayes[J]. Transactions of China Electrotechnical Society, 2022, 37(16): 4250-4258. [9] Rui Li.Analysis and realization method of selective leakage protection technology of self-adaptive full compensation domain[C]//2020 5th International Con- ference on Power and Renewable Energy (ICPRE), Shanghai, China, 2020: 471-475. [10] 司马文霞, 孙佳琪, |杨鸣, 等. 计及铁心非线性的变压器空间动态磁场加速计算方法[J]. 电工技术学报, 2025, 40(5): 1559-1574. Sima Wenxia, Sun Jiaqi, Yang Ming, et al.Acce- lerated calculation method of space dynamic magnetic field of transformer considering core nonlinearity[J]. Transactions of China Electrotechnical Society, 2025, 40(5): 1559-1574. [11] 王亮, 曾伟杰, 田娟, 等. 直流分量和谐波分量对电流互感器传输特性影响[J]. 电机与控制学报, 2023, 27(5): 1-8. Wang Liang, Zeng Weijie, Tian Juan, et al.Influence of DC component and harmonic component on transmission characteristics of current transformer[J]. Electric Machines and Control, 2023, 27(5): 1-8. [12] 段建东, 金转婷, 雷阳, 等. 自动重合闸期间电流互感器剩磁抑制研究[J]. 中国电机工程学报, 2019, 39(5): 1498-1505. Duan Jiandong, Jin Zhuanting, Lei Yang, et al.Study on residual flux suppression of current transformer during automatic reclosing[J]. Proceedings of the CSEE, 2019, 39(5): 1498-1505. [13] 李奎, 解晨雨, 牛峰, 等. 考虑非线性特性的剩余电流互感器建模及其输出调理电路参数设计[J]. 中国电机工程学报, 2022, 42(10): 3815-3826. Li Kui, Xie Chenyu, Niu Feng, et al.Modeling of residual current transformer considering nonlinear characteristics and design of output conditioning circuit parameters[J]. Proceedings of the CSEE, 2022, 42(10): 3815-3826. [14] 李奎, 徐子健, 卢志伟, 等. 电磁式漏电保护特性影响因素分析及其稳健性设计[J]. 电工技术学报, 2023, 38(14): 3930-3942. Li Kui, Xu Zijian, Lu Zhiwei, et al.Factors analysis and robust design of electromagnetic leakage pro- tection characteristics[J]. Transactions of China Electrotechnical Society, 2023, 38(14): 3930-3942. [15] Li Kui, Lin Jingyi, Niu Feng, et al.A novel fault leakage current detection method with protection deadzone elimination[J]. IEEE Transactions on Instru- mentation and Measurement, 2020, 70: 3505009. [16] 李奎, 佟盟, 武一, 等. 磁脱扣器动作响应分析及储能电容匹配设计[J]. 电力自动化设备, 2024, 44(1): 167-173. Li Kui, Tong Meng, Wu Yi, et al.Tripping response analysis and capacitor matching design of magnetic release[J]. Electric Power Automation Equipment, 2024, 44(1): 167-173. [17] 汤龙飞, 柯昌辉, 许志红. 智能单稳态永磁接触器动作特性的联合仿真[J]. 中国电机工程学报, 2023, 43(4): 1641-1651. Tang Longfei, Ke Changhui, Xu Zhihong.Co- simulation of action characteristics of intelligent monostable permanent magnet contactor[J]. Pro- ceedings of the CSEE, 2023, 43(4): 1641-1651. [18] 吴敬轩, 许志红. 电磁接触器吸合过程无模型自适应控制策略[J]. 中国电机工程学报, 2020, 40(5): 1663-1673. Wu Jingxuan, Xu Zhihong.A model-free adaptive control strategy for actuation of electromagnetic contactors[J]. Proceedings of the CSEE, 2020, 40(5): 1663-1673. [19] 李奎, 李常宇, 牛峰, 等. 电磁式漏电断路器的空间磁场抗扰分析及屏蔽结构设计[J]. 电工技术学报, 2022, 37(9): 2161-2169. Li Kui, Li Changyu, Niu Feng, et al.Anti-magnetic field interference analysis and shielding structure design of electromagnetic residual current circuit breaker[J]. Transactions of China Electrotechnical Society, 2022, 37(9): 2161-2169. [20] Li Kui, Luo Chen, Niu Feng, et al.A new magnetic release design with high anti-interference capabi- lity[J]. IEEE Transactions on Magnetics, 2021, 57(5): 4001009. [21] 国家质量监督检验检疫总局, 中国国家标准化管理委员会. 剩余电流动作保护电器: GB/T 6829—2017[S]. 北京: 中国标准出版社, 2018.
2025, Vol. 40 
