Abstract：It is generally believed that the commutation failure of high-voltage direct current transmission (HVDC) is caused by the failure of the receiving-end AC system or the converter valve. However, in engineering practice, it is found that the sending-end AC system failure may also cause the commutation failure of the inverter. At present, most research is limited to the amplitude characteristics of the traditional bus voltage, and its electrical coupling and control coordination needs to be studied. Firstly, by analyzing the response of the AC/DC system after the sending-side fault occurs, it is pointed out that, different from the general receiving-side AC fault, the commutation failure caused by the sending-side AC fault generally occurs in the recovery stage after the fault is removed. Moreover, the magnitude of the bus voltage is not a key factor in such commutation failures. On this basis, the phase characteristics of the bus voltage at the receiving end after the fault is removed are analyzed using the relationship between the active transmission power and the phase angle of the bus voltage. Based on the phase characteristics, the possible commutation failure risk is obtained. The analysis shows that after the fault is removed, restoring the active power transmitted from the sending system to the receiving end will lead to the phase advance of the commutation bus voltage at the receiving end. The phase advance of the bus voltage will not only make the commutation voltage zero-crossing point earlier, but also it will directly compress the commutation area, reduce the turn-off margin from two aspects, and increase the risk of commutation failure. On the other hand, the phase advance will also cause the actual trigger angle of the inverter to exceed the trigger command value, which delays the triggering of the commutator valve on the inverter side during the recovery process and induces commutation failure. In addition, in order to more comprehensively consider other influencing factors of commutation failure, according to the controller response at both ends, this paper further analyzes the changing characteristics of the trigger command and DC current corresponding to the inverter commutation failure process under different fault degrees of the sending-end AC system. The results show that when the AC fault at the sending end is slight and the inverter maintains constant turn-off angle control before and after the fault is removed, the phase shift of the bus voltage at the receiving end and the sudden increase of DC current cause the commutation failure of the inverter. When the fault degree of the sending end deepens and the receiving end inverter switches to constant current control, the phase advance of the bus voltage is often the main reason for the commutation failure. Finally, based on the CIGRE-HVDC simulation model, the correctness of the analysis is verified from the turn-off angle, the voltage of the converter valve, and the voltage and current of the AC and DC systems.
[1] 李培平, 周泓宇, 姚伟, 等. 多馈入结构背景下的高压直流输电系统换相失败研究综述[J]. 电网技术, 2022, 46(3): 834-850. Li Peiping, Zhou Hongyu, Yao Wei, et al.Review of commutation failure on HVDC transmission system under background of multi-infeed structure[J]. Power System Technology, 2022, 46(3): 834-850. [2] 王增平, 刘席洋, 李林泽, 等. 多馈入直流输电系统换相失败边界条件[J]. 电工技术学报, 2017, 32(10): 12-19. Wang Zengping, Liu Xiyang, Li Linze, et al.Boun- dary conditions of commutation failure in multi- infeed HVDC systems[J]. Transactions of China Electrotechnical Society, 2017, 32(10): 12-19. [3] 王玲, 文俊, 李亚男, 等. 谐波对多馈入直流输电系统换相失败的影响[J]. 电工技术学报, 2017, 32(3): 27-34. Wang Ling, Wen Jun, Li Yanan, et al.The harmonic effects on commutation faliure of multi-infeed direct current transmission systems[J]. Transactions of China Electrotechnical Society, 2017, 32(3): 27-34. [4] 程道卫, 刘天琪, 张金, 等. 多落点直流输电系统换相失败影响因素的仿真分析[J]. 电网技术, 2010, 34(11): 59-64. Cheng Daowei, Liu Tianqi, Zhang Jin, et al.Simu- lative analysis on factors impacting commutation failure in multi-terminal HVDC transmission system[J]. Power System Technology, 2010, 34(11): 59-64. [5] 吴萍, 林伟芳, 孙华东, 等. 多馈入直流输电系统换相失败机制及特性[J]. 电网技术, 2012, 36(5): 269-274. Wu Ping, Lin Weifang, Sun Huadong, et al.Research and electromechanical transient simulation on mechanism of commutation failure in multi-infeed HVDC power transmission system[J]. Power System Technology, 2012, 36(5): 269-274. [6] 高本锋, 王刚, 刘毅, 等. LCC-HVDC送端电网等值方案研究[J]. 电工技术学报, 2021, 36(15): 3250-3263, 3271. Gao Benfeng, Wang Gang, Liu Yi, et al.Study on equivalence method of AC system in sending-end of LCC-HVDC[J]. Transactions of China Electro- technical Society, 2021, 36(15): 3250-3263, 3271. [7] 解润生, 张国荣, 高凯, 等. 适用于频变输电线的动态相量谐波分析建模与仿真[J]. 电工技术学报, 2021, 36(15): 3200-3210. Xie Runsheng, Zhang Guorong, Gao Kai, et al.Modeling and simulation of dynamic phasor harmonic analysis for frequency-dependent transmission line[J]. Transactions of China Electrotechnical Society, 2021, 36(15): 3200-3210. [8] 许汉平, 杨炜晨, 张东寅, 等. 考虑换相失败相互影响的多馈入高压直流系统换相失败判断方法[J]. 电工技术学报, 2020, 35(8): 1776-1786. Xu Hanping, Yang Weichen, Zhang Dongyin, et al.Commutation failure judgment method for multi- infeed HVDC systems considering the interaction of commutation failures[J]. Transactions of China Electrotechnical Society, 2020, 35(8): 1776-1786. [9] 夏成军, 王真, 杜兆斌. 考虑直流系统控制方式的多馈入交互作用因子实用计算方法[J]. 电网技术, 2017, 41(11): 3532-3540. Xia Chengjun, Wang Zhen, Du Zhaobin.Practical calculation method for multi-infeed interaction factor considering HVDC system control modes[J]. Power System Technology, 2017, 41(11): 3532-3540. [10] Andersen B R, Xu Lie.Hybrid HVDC system for power transmission to island networks[J]. IEEE Transactions on Power Delivery, 2004, 19(4): 1884-1890. [11] Son H I, Kim H M.An algorithm for effective mitigation of commutation failure in high-voltage direct-current systems[J]. IEEE Transactions on Power Delivery, 2016, 31(4): 1437-1446. [12] 王增平, 刘席洋, 郑博文, 等. 基于电压波形拟合的换相失败快速预测与抑制措施[J]. 电工技术学报, 2020, 35(7): 1454-1463. Wang Zengping, Liu Xiyang, Zheng Bowen, et al.The research on fast prediction and suppression measures of commutation failure based on voltage waveform fitting[J]. Transactions of China Electrotechnical Society, 2020, 35(7): 1454-1463. [13] 束洪春, 代月, 安娜, 等. 基于线性回归的柔性直流电网纵联保护方法[J]. 电工技术学报, 2022, 37(13): 3213-3226, 3288. Shu Hongchun, Dai Yue, An Na, et al.Pilot protection method of flexible DC grid based on linear regression[J]. Transactions of China Electrotechnical Society, 2022, 37(13): 3213-3226, 3288. [14] Xiao Hao, Li Yinhong, Lan Tongkun.Sending end AC faults can cause commutation failure in LCC- HVDC inverters[J]. IEEE Transactions on Power Delivery, 2020, 35(5): 2554-2557. [15] 林圣, 雷雨晴, 刘健, 等. HVDC送端系统故障引发受端换相失败分析[J]. 中国电机工程学报, 2022, 42(5): 1669-1680. Lin Sheng, Lei Yuqing, Liu Jian, et al.Analysis of receiving-side commutation failure mechanism caused by HVDC sending-side system fault[J]. Proceedings of the CSEE, 2022, 42(5): 1669-1680. [16] Hong Lerong, Zhou Xiaoping, Xia Haitao, et al.Mechanism and prevention of commutation failure in LCC-HVDC caused by sending end AC faults[J]. IEEE Transactions on Power Delivery, 2021, 36(1): 473-476. [17] 汤奕, 郑晨一, 楼伯良, 等. 抑制连续换相失败的直流功率控制策略[J]. 电网技术, 2019, 43(10): 3514-3522. Tang Yi, Zheng Chenyi, Lou Boliang, et al.Research on DC power control strategy for mitigating continuous commutation failure[J]. Power System Technology, 2019, 43(10): 3514-3522. [18] 汪娟娟, 文兆新, 傅闯, 等. 基于换相电压相位检测的高压直流故障恢复策略[J]. 电网技术, 2019, 43(10): 3504-3514. Wang Juanjuan, Wen Zhaoxin, Fu Chuang, et al.HVDC fault recovery strategy based on phase change detection of commutation voltage[J]. Power System Technology, 2019, 43(10): 3504-3514. [19] 王子民, 傅闯, 汪娟娟, 等. 锁相环对HVDC系统后续换相失败的影响研究[J]. 中国电机工程学报, 2019, 39(23): 6836-6843, 7097. Wang Zimin, Fu Chuang, Wang Juanjuan, et al.Study on the influence of phase-locked loop on follow-up commutation failure of HVDC system[J]. Proceedings of the CSEE, 2019, 39(23): 6836-6843, 7097. [20] 曾君, 岑德海, 陈润, 等. 针对直流偏移和谐波干扰的单相锁相环[J]. 电工技术学报, 2021, 36(16): 3504-3515. Zeng Jun, Cen Dehai, Chen Run, et al.Single-phase phase-locked loop for DC offset and harmonic inter- ference[J]. Transactions of China Electrotechnical Society, 2021, 36(16): 3504-3515. [21] 何宇, 漆汉宏, 邓小龙. 基于全复数型滤波器的三相锁相环技术[J]. 电工技术学报, 2021, 36(10): 2115-2126. He Yu, Qi Hanhong, Deng Xiaolong.A three-phase phase-locked loop technique based on all complex coefficient filter[J]. Transactions of China Electro- technical Society, 2021, 36(10): 2115-2126. [22] 龚英明, 汪娟娟, 王子民, 等. 一种应用于高压直流输电的新型锁相环[J]. 电网技术, 2019, 43(11): 4097-4104. Gong Yingming, Wang Juanjuan, Wang Zimin, et al.A novel phase-locked loop for HVDC[J]. Power System Technology, 2019, 43(11): 4097-4104. [23] 朱仁龙, 周小平, 罗安, 等. 基于电压时间换相面积预测的换相失败抑制方法[J]. 电力系统自动化, 2022, 46(3): 156-163. Zhu Renlong, Zhou Xiaoping, Luo An, et al.Commutation failure mitigation method based on voltage-time commutation area prediction[J]. Auto- mation of Electric Power Systems, 2022, 46(3): 156-163.
2023, Vol. 38 
