A Multi-Port DC Circuit Breaker with Fault-Current Limiting Capability
Li Hao1, Pei Xiangyu1, Li Zewen1, Zhou Wandi2, Li Pengzhi2
1. School of Electrical and Information Engineering Changsha University of Science & Technology Changsha 410114 China; 2. State Key Laboratory of Advanced Power Transmission Technology State Grid Smart Grid Research Institute Co. Ltd Beijing 102209 China
Abstract The hybrid DC circuit breaker (DCCB) is the critical equipment to realize the fast interruption of fault currents for VSC-based DC grids. However, with the continuous expansion of VSC-based DC grids, based on the local protection strategy, each DC line must be equipped with an expensive two-port hybrid DCCB at both ends. It causes enormous project investment costs and seriously restricts the large-scale application of hybrid DCCB in future complex DC grid projects. Therefore, this paper proposes a multi-port DCCB with fault current limiting capability (FCL-MHDCB) to improve the fault current limiting effect by optimizing the overall operation sequence. At the same time, after the DC bus fault isolation is completed, based on the proposed FCL-MHDCB scheme, the healthy DC lines connected to the fault bus can still carry out normal power transmission, which greatly improves the power supply reliability of the system. Firstly, the FCL-MHDCB topology is proposed, which consists of the main branch, transfer branch, energy dissipation branch, current limiting unit, and auxiliary unit. Secondly, the fault current blocking principle of the proposed FCL-MHDCB under DC line fault conditions is analyzed. The working process can be divided into three stages: the steady-state operation stage, the fault current limiting stage, and the fault current interruption stage. Thirdly, taking the n-terminal VSC-based DC grids as an example, the action process of the proposed FCL-MHDCB is theoretically deduced. The proposed scheme is verified by the derived formula. Finally, considering the thyristor withstand voltage, fault current peak, full input time of current limiting inductor, and current limiting effect, the value range of pre-charged capacitor C and current limiting inductor LFCL in the current limiting unit is designed. Considering comprehensively, the range of capacitor C can be determined to be 10~15 μF, and the range of inductor LFCL can be determined to be 0.1~0.15 H. In general, to highlight the advantages of the proposed FCL-MHDCB, a metal grounding fault occurs at the bus of the positive outlet of the converter station at t =3 s. The simulation results of the port current show that the proposed FCL-MHDCB can still maintain the power transmission of the sound line after DC bus fault isolation, which ensures the continuous and reliable operation of VSC-based DC grids to the greatest extent. In addition, the simulation results of each branch current of the proposed FCL-MHDCB show that it can effectively complete the fault current suppression and fast blocking. At about 3.011 s, the fault current drops to 0 under the transient breaking voltage of metal oxide varistors, and FCL-MHDCB completes the fault current interruption. Compared with the multi-port DCCB without the current limiting unit, the peak fault current is as high as 9.09 kA at 3.006 s, while the peak fault current of the proposed FCL-MHDCB is only 5.64 kA, reducing by 38.0 %. Moreover, the energy dissipation stress of the arrester is reduced by 61.21 % compared with the conventional scheme. The following conclusions can be drawn from the simulation analysis: (1) Compared with the existing technical scheme, the proposed FCL-MHDCB can still transmit power between healthy lines after completing the DC bus fault isolation, ensuring the continuous and reliable operation of VSC-based DC grids to the greatest extent. (2) When the circuit breaker recloses in the permanent fault, the permanent fault isolation can be quickly realized only by coordinating the thyristors in the ordered conduction current limiting unit with the pre-charged capacitors. Immediately charging the capacitors of the current limiting unit is not needed. (3) The whole action sequence of DCCB is optimized, and the limiting effect of fault current is improved. The peak value of fault current decreases by 38.0 %, and the energy dissipation stress of the arrester decreases by 61.21 %.
Li Hao,Pei Xiangyu,Li Zewen等. A Multi-Port DC Circuit Breaker with Fault-Current Limiting Capability[J]. Transactions of China Electrotechnical Society, 2023, 38(10): 2818-2831.
[1] 李晖, 刘栋, 姚丹阳. 面向碳达峰碳中和目标的我国电力系统发展研判[J]. 中国电机工程学报, 2021, 41(18): 6245-6259. Li Hui, Liu Dong, Yao Danyang.Analysis and reflection on the development of power system towards the goal of carbon emission peak and carbon neutrality[J]. Proceedings of the CSEE, 2021, 41(18): 6245-6259. [2] 汤广福, 庞辉, 贺之渊. 先进交直流输电技术在中国的发展与应用[J]. 中国电机工程学报, 2016, 36(7): 1760-1771. Tang Guangfu, Pang Hui, He Zhiyuan.R & D and application of advanced power transmission tech- nology in China[J]. Proceedings of the CSEE, 2016, 36(7): 1760-1771. [3] 郝瑞祥, 杨晓峰, 薛尧, 等. 一种具有直流故障限流能力的模块化多电平换流器[J]. 电工技术学报, 2017, 32(6): 172-180. Hao Ruixiang, Yang Xiaofeng, Xue Yao, et al.A novel modular multilevel converter with DC fault current limiting capability[J]. Transactions of China Electrotechnical Society, 2017, 32(6): 172-180. [4] 袁佳歆, 陈鹤冲, 陈凡, 等. 一种快速响应直流限流器拓扑结构与参数设计[J]. 电工技术学报, 2021, 36(8): 1646-1657. Yuan Jiaxin, Chen Hechong, Chen Fan, et al.Topology and parameter design of a fast response DC current limiter[J]. Transactions of China Electro- technical Society, 2021, 36(8): 1646-1657. [5] 周万迪, 魏晓光, 高冲, 等. 基于晶闸管的混合型无弧高压直流断路器[J]. 中国电机工程学报, 2014, 34(18): 2990-2996. Zhou Wandi, Wei Xiaoguang, Gao Chong, et al.Thyristor based hybrid arc-less high voltage direct current circuit breaker[J]. Proceedings of the CSEE, 2014, 34(18): 2990-2996. [6] 裴翔羽, 汤广福, 庞辉, 等. 柔性直流电网线路保护与直流断路器优化协调配合策略研究[J]. 中国电机工程学报, 2018, 38(增刊1): 11-18. Pei Xiangyu, Tang Guangfu, Pang Hui, et al.Study on optimized coordination strategies between line pro- tection and DC breakers for VSC-based DC grid[J]. Proceedings of the CSEE, 2018, 38(S1): 11-18. [7] 程显, 徐鹏飞, 葛国伟, 等. 机械式真空直流断路器弧后电流测量研究[J]. 电工技术学报, 2021, 36(16): 3516-3524. Cheng Xian, Xu Pengfei, Ge Guowei, et al.Research on measurement of post-arc current of mechanical vacuum DC circuit breaker[J]. Transactions of China Electrotechnical Society, 2021, 36(16): 3516-3524. [8] 李斌, 李鹏宇, 温伟杰, 等. 机械式直流断路器性能分析及谐振换流方法[J]. 电工技术学报, 2022, 37(9): 2139-2149. Li Bin, Li Pengyu, Wen Weijie, et al.Performance analysis and resonant commutation method of mechanical DC circuit breaker[J]. Transactions of China Electrotechnical Society, 2022, 37(9): 2139-2149. [9] 陈龙龙, 魏晓光, 焦重庆, 等. 混合式高压直流断路器分断过程电磁瞬态建模和测试[J]. 电工技术学报, 2021, 36(24): 5261-5271. Chen Longlong, Wei Xiaoguang, Jiao Chongqing, et al.Electromagnetic transient modeling and test of hybrid DC circuit breaker[J]. Transactions of China Electrotechnical Society, 2021, 36(24): 5261-5271. [10] 魏晓光, 周万迪, 张升, 等. 模块化混合式高压直流断路器研究与应用[J]. 中国电机工程学报, 2020, 40(6): 2038-2047. Wei Xiaoguang, Zhou Wandi, Zhang Sheng, et al.Research and application of modular hybrid high voltage DC circuit breaker[J]. Proceedings of the CSEE, 2020, 40(6): 2038-2047. [11] 汤广福, 王高勇, 贺之渊, 等. 张北500kV直流电网关键技术与设备研究[J]. 高电压技术, 2018, 44(7): 2097-2106. Tang Guangfu, Wang Gaoyong, He Zhiyuan, et al.Research on key technology and equipment for Zhangbei 500kV DC grid[J]. High Voltage Engin- eering, 2018, 44(7): 2097-2106. [12] 张盛梅, 安婷, 裴翔羽, 等. 混合式直流断路器重合闸策略[J]. 电力系统自动化, 2019, 43(6): 129-136. Zhang Shengmei, An Ting, Pei Xiangyu, et al.Reclosing strategy for hybrid DC circuit breakers[J]. Automation of Electric Power Systems, 2019, 43(6): 129-136. [13] Zhang Fan, Ren Yu, Shi Zenan, et al.Novel hybrid DC circuit breaker based on series connection of thyristors and IGBT half-bridge submodules[J]. IEEE Transactions on Power Electronics, 2021, 36(2): 1506-1518. [14] Wang Sheng, Ugalde-Loo C E, Li Chuanyue, et al. Bridge-type integrated hybrid DC circuit breakers[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2020, 8(2): 1134-1151. [15] Wen Weijie, Li Bin, Li Botong, et al.Analysis and experiment of a micro-loss multi-port hybrid DCCB for MVDC distribution system[J]. IEEE Transactions on Power Electronics, 2019, 34(8): 7933-7941. [16] Zhang Shuo, Zou Guibin, Wei Xiuyan, et al.Diode- bridge multiport hybrid DC circuit breaker for multiterminal DC grids[J]. IEEE Transactions on Industrial Electronics, 2021, 68(1): 270-281. [17] He Jinghan, Luo Yiping, Li Meng, et al.A high- performance and economical multiport hybrid direct current circuit breaker[J]. IEEE Transactions on Industrial Electronics, 2020, 67(10): 8921-8930. [18] 韩乃峥, 樊强, 贾秀芳, 等. 一种具备限流能力的多端口直流断路器[J]. 中国电机工程学报, 2019, 39(17): 5172-5181, 5298. Han Naizheng, Fan Qiang, Jia Xiufang, et al.A multi-port DC circuit breaker with current limiting capability[J]. Proceedings of the CSEE, 2019, 39(17): 5172-5181, 5298. [19] 宋冰倩, 赵成勇, 许建中. 适用于直流电网的多端口限流式直流故障保护方案[J]. 中国电机工程学报, 2020, 40(4): 1185-1195, 1410. Song Bingqian, Zhao Chengyong, Xu Jianzhong.Multi-port current-limiting HVDC fault protection scheme for DC grid[J]. Proceedings of the CSEE, 2020, 40(4): 1185-1195, 1410. [20] 王华清, 程显, 葛国伟, 等. 中压混合式直流断路器真空短间隙介质恢复特性[J]. 电网技术, 2020, 44(1): 377-384. Wang Huaqing, Cheng Xian, Ge Guowei, et al.Investigation on dielectric recovery performance of short vacuum gap in medium-voltage hybrid DC circuit breakers[J]. Power System Technology, 2020, 44(1): 377-384.
2023, Vol. 38 
