不对称电网单相接地故障中性点位移电压轨迹分析及应用
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摘要
忽略不对称电压方向的任意性,不能准确表达配电网单相接地时中性点位移电压随过渡电阻变化的轨迹。考虑系统对地泄露电导及不对称电压方向,建立单相接地故障精确模型,准确分析出非全补偿状态下中性点位移电压随过渡电阻变化的轨迹是一段圆弧,全补偿状态下中性点位移电压随过渡电阻变化的轨迹是一条直线段。分析中性点位移电压轨迹,得到以下结论:接地后故障相电压幅值降低,欠补偿状态下接地后故障相电压超前于故障前该相电压,过补偿状态下接地后故障相电压相位滞后于故障前该相电压,全补偿状态下接地前后故障相电压相位保持不变。比较故障前后三相电压幅值与相位的相对变化关系可实现接地故障相辨识。最后,通过MATLAB/Simulink仿真验证了分析结果。
If the arbitrariness of the asymmetrical voltage direction is ignored, it is impossible to accurately describe the trajectory of neutral point displacement voltage varying with the transition resistance when a single-phase grounding fault occurs in the distribution network. Considering the conductance of ground leakage and the direction of asymmetrical voltage, an accurate model of single-phase grounding fault is established. In the incomplete compensation state, the trajectory of neutral point displacement voltage varing with transition resistance is a circular arc; in the full compensation state, the trajectory of neutral point displacement voltage varied with transition resistance is a straight-line segment. According to the analysis: the amplitude of fault phase voltage decreases after grounding, the fault phase voltage after grounding is ahead of the phase voltage before fault in the under-compensated state, the fault phase voltage after grounding lags behind the phase voltage before fault in the over-compensated state, the voltage of the fault phase before and after grounding remains unchanged in the fully compensated state. By comparing the relative change of amplitude and phase of three-phase voltage before and after fault, the grounding fault phase can be identified. Finally, the analysis are verified by MATLAB/Simulink simulations.
If the arbitrariness of the asymmetrical voltage direction is ignored, it is impossible to accurately describe the trajectory of neutral point displacement voltage varying with the transition resistance when a single-phase grounding fault occurs in the distribution network. Considering the conductance of ground leakage and the direction of asymmetrical voltage, an accurate model of single-phase grounding fault is established. In the incomplete compensation state, the trajectory of neutral point displacement voltage varing with transition resistance is a circular arc; in the full compensation state, the trajectory of neutral point displacement voltage varied with transition resistance is a straight-line segment. According to the analysis: the amplitude of fault phase voltage decreases after grounding, the fault phase voltage after grounding is ahead of the phase voltage before fault in the under-compensated state, the fault phase voltage after grounding lags behind the phase voltage before fault in the over-compensated state, the voltage of the fault phase before and after grounding remains unchanged in the fully compensated state. By comparing the relative change of amplitude and phase of three-phase voltage before and after fault, the grounding fault phase can be identified. Finally, the analysis are verified by MATLAB/Simulink simulations.
引文
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[7] 周封,朱瑞,王晨光,等.一种配电网高阻接地故障在线监测与辨识方法[J].仪器仪表学报,2015,36(3):685-693.ZHOU Feng, ZHU Rui, WANG Chenguang, et al. A method for online criterion and identification of single phase-ground fault with high resistance in distribution network[J]. Chinese Journal of Scientific Instrument, 2015, 36(3): 685-693.
[8] 于群,陈志慧.电网不对称条件下基于频数分布理论的谐振接地系统故障相辨识[J].电力系统保护与控制,2018,46(7):96-104.YU Qun, CHEN Zhihui. Grounding phase determination in resonant grounding systems based on frequency distribution theory in case of unsymmetrical voltage[J]. Power System Protection and Control, 2018, 46(7): 96-104.
[9] 李如琦,黄欢,张振兴,等.小电流系统单相不完全接地故障分析[J].广西大学学报(自然科学版),2007,32(4):367-370.LI Ruqi, HUANG Huan, ZHANG Zhenxing, et al. Analyzing of single-phase and indirectly grounding fault in small current system[J]. Journal of Guangxi University (Natural Science Edition), 2007, 32(4): 367-370.
[10] 徐波,张建文,蔡旭,等.电网不对称条件下小电流接地系统接地相辨识[J].电工技术学报,2011,26(12):175-182.XU Bo, ZHANG Jianwen, CAI Xu, et al. Grounding phase determination in non-effective grounding systems in case of the identification of small current grounding system in unsymmetric voltage[J]. Transactions of China Electrotechnical Society, 2011, 26(12): 175-182.
[11] 刘宝稳,王崇林,李晓波.不对称电网不完全接地故障零序电压轨迹及应用[J].中国电机工程学报,2014,34(28):4959-4967.LIU Baowen, WANG Chonglin, LI Xiaobo. Analysis and application of zero-sequence voltage of single-phase ground fault asymmetrical system[J]. Proceedings of the CSEE, 2014, 34(28): 4959-4967.
[12] 艾绍贵,李秀广,黎炜,等.配电网快速开关型消除弧光接地故障技术研究[J].高压电器,2017,53(3):178-184.AI Shaogui, LI Xiuguang, LI Wei, et al. Arc suppression technology based on fast switch for distribution network[J]. High Voltage Apparatus, 2017, 53(3): 178-184.
[13] 赵军,袁雪琼,阮琦,等.基于对地参数跟踪测量的不接地系统单相接地故障选相研究[J].电力系统保护与控制,2015,43(21):81-85.ZHAO Jun, YUAN Xueqiong, RUAN Qi, et al. Research on single phase grounding fault phase selection based on ground parameter tracking and measurement[J]. Power System Protection and Control, 2015, 43(21): 81-85.
[14] 刘宝稳,马宏忠.零序电压产生机理及过渡电阻测量和选相方法[J].电网技术,2015,39(5):1444-1449.LIU Baowen, MA Hongzhong. Transition resistance measurement and fault phase selection under single-phase ground fault based on producing mechanism of zero-sequence voltage[J]. Power System Technology, 2015, 39(5): 1444-1449.
[15] 齐郑,郑宇航,杭天琦,等.基于暂态过程的非有效接地系统故障相辨识方法[J].电力系统自动化,2018,42(16):155-160.DOI:10.7500/AEPS20171202001.QI Zheng, ZHENG Yuhang, HANG Tianqi, et al. Transient process based fault phase identification method for non-effectively grounded system[J]. Automation of Electric Power Systems, 2018, 42(16): 155-160. DOI: 10.7500/AEPS20171202001.
[16] 刘宝稳,马宏忠,沈培锋,等.新型接地故障基波电流全补偿柔性控制系统[J].中国电机工程学报,2016,36(9):2322-2330.LIU Baowen, MA Hongzhong, SHEN Peifeng, et al. New flexible control system of full compensation single-phase ground fault fundamental current[J]. Proceedings of the CSEE, 2016, 36(9): 2322-2330.
[2] 赵军,阮琦,李景禄.考虑线路压降的快速接地开关消弧性能及应用分析[J].电力系统自动化,2018,42(20):158-164.DOI:10.7500/AEPS20180109010.ZHAO Jun, RUAN Qi, LI Jinglu. Arc eliminating performance and application of fast grounding switch considering line voltage drop[J]. Automation of Electric Power Systems, 2018, 42(20): 158-164. DOI: 10.7500/AEPS20180109010.
[3] 郭谋发,游建章,林先辉,等.适应线路参数及负载变化的配电网柔性优化消弧方法[J].电力系统自动化,2017,41(8):138-145.DOI:10.7500/AEPS20160621001.GUO Moufa, YOU Jianzhang, LIN Xianhui, et al. Flexible arc-suppression optimization method for distribution network adaptable to variation of line parameters and load[J]. Automation of Electric Power Systems, 2017, 41(8): 138-145. DOI: 10.7500/AEPS20160621001.
[4] 刘健,王玉庆,芮骏,等.智能接地配电系统关键参数设计[J].电力系统自动化,2018,42(16):180-186.DOI:10.7500/AEPS20171031004.LIU Jian, WANG Yuqing, RUI Jun, et al. Key parameter design of smart grounding distribution systems[J]. Automation of Electric Power Systems, 2018, 42(16): 180-186. DOI: 10.7500/AEPS20171031004.
[5] 姜杰,赵广泉,张肖,等.利用正弦拟合法的铁磁谐振与单相接地辨识[J].重庆大学学报,2014,37(8):34-40.JIANG Jie, ZHAO Guangquan, ZHANG Xiao, et al. Discriminate ferroresonance from single-phase earth fault in sine fitting algorithm[J]. Journal of Chongqing University (Natural Science Edition), 2014, 37(8): 34-40.
[6] 马杰,李磊,李乃永,等.基于故障信息的高阻接地故障辨识与定位方法[J].电力系统保护与控制,2013,41(11):74-78.MA Jie, LI Lei, LI Naiyong, et al. Identification and location of high-resistance grounding fault based on fault records[J]. Power System Protection and Control, 2013, 41(11): 74-78.
[7] 周封,朱瑞,王晨光,等.一种配电网高阻接地故障在线监测与辨识方法[J].仪器仪表学报,2015,36(3):685-693.ZHOU Feng, ZHU Rui, WANG Chenguang, et al. A method for online criterion and identification of single phase-ground fault with high resistance in distribution network[J]. Chinese Journal of Scientific Instrument, 2015, 36(3): 685-693.
[8] 于群,陈志慧.电网不对称条件下基于频数分布理论的谐振接地系统故障相辨识[J].电力系统保护与控制,2018,46(7):96-104.YU Qun, CHEN Zhihui. Grounding phase determination in resonant grounding systems based on frequency distribution theory in case of unsymmetrical voltage[J]. Power System Protection and Control, 2018, 46(7): 96-104.
[9] 李如琦,黄欢,张振兴,等.小电流系统单相不完全接地故障分析[J].广西大学学报(自然科学版),2007,32(4):367-370.LI Ruqi, HUANG Huan, ZHANG Zhenxing, et al. Analyzing of single-phase and indirectly grounding fault in small current system[J]. Journal of Guangxi University (Natural Science Edition), 2007, 32(4): 367-370.
[10] 徐波,张建文,蔡旭,等.电网不对称条件下小电流接地系统接地相辨识[J].电工技术学报,2011,26(12):175-182.XU Bo, ZHANG Jianwen, CAI Xu, et al. Grounding phase determination in non-effective grounding systems in case of the identification of small current grounding system in unsymmetric voltage[J]. Transactions of China Electrotechnical Society, 2011, 26(12): 175-182.
[11] 刘宝稳,王崇林,李晓波.不对称电网不完全接地故障零序电压轨迹及应用[J].中国电机工程学报,2014,34(28):4959-4967.LIU Baowen, WANG Chonglin, LI Xiaobo. Analysis and application of zero-sequence voltage of single-phase ground fault asymmetrical system[J]. Proceedings of the CSEE, 2014, 34(28): 4959-4967.
[12] 艾绍贵,李秀广,黎炜,等.配电网快速开关型消除弧光接地故障技术研究[J].高压电器,2017,53(3):178-184.AI Shaogui, LI Xiuguang, LI Wei, et al. Arc suppression technology based on fast switch for distribution network[J]. High Voltage Apparatus, 2017, 53(3): 178-184.
[13] 赵军,袁雪琼,阮琦,等.基于对地参数跟踪测量的不接地系统单相接地故障选相研究[J].电力系统保护与控制,2015,43(21):81-85.ZHAO Jun, YUAN Xueqiong, RUAN Qi, et al. Research on single phase grounding fault phase selection based on ground parameter tracking and measurement[J]. Power System Protection and Control, 2015, 43(21): 81-85.
[14] 刘宝稳,马宏忠.零序电压产生机理及过渡电阻测量和选相方法[J].电网技术,2015,39(5):1444-1449.LIU Baowen, MA Hongzhong. Transition resistance measurement and fault phase selection under single-phase ground fault based on producing mechanism of zero-sequence voltage[J]. Power System Technology, 2015, 39(5): 1444-1449.
[15] 齐郑,郑宇航,杭天琦,等.基于暂态过程的非有效接地系统故障相辨识方法[J].电力系统自动化,2018,42(16):155-160.DOI:10.7500/AEPS20171202001.QI Zheng, ZHENG Yuhang, HANG Tianqi, et al. Transient process based fault phase identification method for non-effectively grounded system[J]. Automation of Electric Power Systems, 2018, 42(16): 155-160. DOI: 10.7500/AEPS20171202001.
[16] 刘宝稳,马宏忠,沈培锋,等.新型接地故障基波电流全补偿柔性控制系统[J].中国电机工程学报,2016,36(9):2322-2330.LIU Baowen, MA Hongzhong, SHEN Peifeng, et al. New flexible control system of full compensation single-phase ground fault fundamental current[J]. Proceedings of the CSEE, 2016, 36(9): 2322-2330.