小电阻接地系统高灵敏性零序电流保护
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摘要
对小电阻接地系统的零序电压、电流关系进行分析,发现发生高阻接地故障时母线零序电压与故障线路零序电流存在比例关系,则零序电压可间接反映过渡电阻的大小,由此提出一种基于零序电压幅值修正的高灵敏性零序电流保护方案。该方案结合现有的零序电流保护原理,通过引入零序电压信息对零序电流测量值进行修正,各线路修正后的零序电流测量值与故障线路首端发生金属性接地故障时的情况相似,保护动作整定值与现有的阶段式零序电流保护相同,从而大幅提高保护在高阻接地故障时的灵敏性。结合工程实际因素,讨论了各参数的整定原则。基于PSCAD/EMTDC的仿真和基于RTDS的装置测试验证了所提保护方案的有效性,其可将保护耐受过渡电阻能力提高到1 000Ω左右。
The relationship between zero-sequence voltage and current of low-resistance grounding system is analyzed,which reveals that the zero-sequence voltage of bus is proportional to the zero-sequence current of fault line when high impedance grounding fault occurs. Thus,the value of fault resistance can be indirectly reflected by zerosequence voltage. On this basis,a high sensitive zero-sequence current protection scheme based on magnitude revise of zero-sequence voltage is proposed. Combining with the principle of the existing zero-sequence current protection,the measuring value of zero-sequence current is revised by the zero-sequence voltage. The revised value of zerosequence current of each feeder is similar to that under single-phase metallic grounding fault at the head of the line,and the setting values of the proposed scheme are similar to those of the existing zero-sequence current protection,so the sensitivity of protection is significantly improved under high impedance grounding fault. The specific setting principles of parameters for the proposed scheme are discussed considering the factors of practical engineering. The simulation in PSCAD/EMTDC and the RTDS-based digital dynamic device test of actual protections prove that the proposed scheme is effective and the capability of the fault resistance endurance can be increased to about 1 000 Ω.
The relationship between zero-sequence voltage and current of low-resistance grounding system is analyzed,which reveals that the zero-sequence voltage of bus is proportional to the zero-sequence current of fault line when high impedance grounding fault occurs. Thus,the value of fault resistance can be indirectly reflected by zerosequence voltage. On this basis,a high sensitive zero-sequence current protection scheme based on magnitude revise of zero-sequence voltage is proposed. Combining with the principle of the existing zero-sequence current protection,the measuring value of zero-sequence current is revised by the zero-sequence voltage. The revised value of zerosequence current of each feeder is similar to that under single-phase metallic grounding fault at the head of the line,and the setting values of the proposed scheme are similar to those of the existing zero-sequence current protection,so the sensitivity of protection is significantly improved under high impedance grounding fault. The specific setting principles of parameters for the proposed scheme are discussed considering the factors of practical engineering. The simulation in PSCAD/EMTDC and the RTDS-based digital dynamic device test of actual protections prove that the proposed scheme is effective and the capability of the fault resistance endurance can be increased to about 1 000 Ω.
引文
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[11]薛永端,刘珊,王艳松,等.基于零序电压比率制动的小电阻接地系统接地保护[J].电力系统自动化,2016,40(16):112-117.XUE Yongduan,LIU Shan,WANG Yansong,et al.Grounding fault protection in low resistance grounding system based on zerosequence voltage ratio restraint[J].Automation of Electric PowerSystems,2016,40(16):112-117.
[12]于建龙,陈忠仁,张勤,等.自动补偿消弧装置运行问题探讨[J].高电压技术,2005,31(7):80-81.YU Jianlong,CHEN Zhongren,ZHANG Qin,et al.Study on abnormal operation of auto compensation arc-suppression device[J].High Voltage Engineering,2005,31(7):80-81.
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[14]蒋仁江,英云龙,秦志成,等.Z型接地变压器在PSCAD下的仿真模型构建[J].价值工程,2015,29:137-138.JIANG Renjiang,YING Yunlong,QIN Zhicheng,et al.Simulation model of zigzag grounding transformer by PSCAD[J].Value Engineering,2015,29:137-138.
[15]陈锦胜.配电线路使用PSCAD电缆模型建模[J].广东电力,2015,28(3):82-85.CHEN Jinsheng.Modeling for power distribution lines by using pscad cable model[J].Guangdong Electric Power,2015,28(3):82-85.
[16]许晔,郭谋发,陈彬,等.配电网单相接地电弧建模及仿真分析研究[J].电力系统保护与控制,2015,43(7):57-64.XU Ye,GUO Moufa,CHEN Bin,et al.Modeling and simulation analysis of arc in distribution network[J].Power System Protection and Control,2015,43(7):57-64.
[17]王倩,谭王景,叶赞,等.基于ATP-EMTP的电弧接地故障的建模及仿真[J].电网与清洁能源,2015,31(1):16-21.WANG Qian,TAN Wangjing,YE Zan,et al.Modeling and simulating of arc grounding fault based on ATP-EMTP[J].Power System and Clean Energy,2015,31(1):16-21.
[18]曾德辉.含分布式电源配电网和微电网故障分析与保护新原理研究[D].广州:华南理工大学,2016.ZENG Dehui.New protection principles of distribution network and micro grid with distributed generation[D].Guangzou:South China University of Technology,2016.
[2]刘育权,蔡燕春,邓国豪,等.小电阻接地方式配电系统的运行与保护[J].供用电,2015,32(6):30-35.LIU Yuquan,CAI Yanchun,DENG Guohao,et al.Operation and protection in distribution system with small resistance grounding mode[J].Distribution&Utilization,2015,32(6):30-35.
[3]江文东.10 k V小电阻接地系统零序过流定值的探讨[J].电力自动化设备,2002,22(10):73-75.JIANG Wendong.Discussion on zero sequence overcurrent settings for 10 k V low resistance grounding system[J].Electric Power Automation Equipment,2002,22(10):73-75.
[4]SOHEILI A,SADEH S J,LOMEI H,et al.A new high impedance fault detection scheme:Fourier based approach[C]∥2016 IEEE International Conference on Power System Technology(POWERCON).Wollongong,NSW,Australia:IEEE,2016:1-6.
[5]SANTOS W C,LOPES F V,BRITO N S D,et al.High-impedance fault identification on distribution networks[J].IEEE Transactions on Power Delivery,2017,32(1):23-32.
[6]SAMANTARAY S R,PANIGRAHI B K,DASH P K.High impedance fault detection in power distribution networks using time-frequency transform and probabilistic neural network[J].IET Generation,Transmission&Distribution,2008,2(2):261-270.
[7]李震球,王时胜,吴丽娜,等.一种谐振接地系统电弧高阻接地故障选线新方法及仿真[J].电力系统保护与控制,2014,42(17):44-49.LI Zhenqiu,WANG Shisheng,WU Lina,et al.A new method and simulation for arcing high impedance grounding fault line selection in resonant grounded system[J].Power System Protection and Control,2014,42(17):44-49.
[8]王宾,耿建昭,董新洲.配网高阻接地故障伏安特性分析及检测[J].中国电机工程学报,2014,34(22):3815-3823.WANG Bin,GENG Jianzhao,DONG Xinzhou.Analysis and detection of volt-ampere characteristics for high impedance faults in distribution systems[J].Proceedings of the CSEE,2014,34(22):3815-3823.
[9]耿建昭,王宾,董新洲,等.中性点有效接地配电网高阻接地故障特征分析及检测[J].电力系统自动化,2013,37(16):85-91.GENG Jianzhao,WANG Bin,DONG Xinzhou,et al.Analysis and detection of high impedance grounding fault in neutral point effectively grounding distribution network[J].Automation of Electric Power Systems,2013,37(16):85-91.
[10]许庆强,许扬,周栋骥,等.小电阻接地配电网线路保护单相高阻接地分析[J].电力系统自动化,2010,34(9):91-94,115.XU Qingqiang,XU Yang,ZHOU Dongji,et al.Analysis of distribution network line relay protection during single-phase highresistance grounding faults in low resistance neutral grounded system[J].Automation of Electric Power Systems,2010,34(9):91-94,115.
[11]薛永端,刘珊,王艳松,等.基于零序电压比率制动的小电阻接地系统接地保护[J].电力系统自动化,2016,40(16):112-117.XUE Yongduan,LIU Shan,WANG Yansong,et al.Grounding fault protection in low resistance grounding system based on zerosequence voltage ratio restraint[J].Automation of Electric PowerSystems,2016,40(16):112-117.
[12]于建龙,陈忠仁,张勤,等.自动补偿消弧装置运行问题探讨[J].高电压技术,2005,31(7):80-81.YU Jianlong,CHEN Zhongren,ZHANG Qin,et al.Study on abnormal operation of auto compensation arc-suppression device[J].High Voltage Engineering,2005,31(7):80-81.
[13]李宁,赵东.10 k V电压互感器在投运时开口三角电压异常分析[J].电气制造,2014(2):64-66.
[14]蒋仁江,英云龙,秦志成,等.Z型接地变压器在PSCAD下的仿真模型构建[J].价值工程,2015,29:137-138.JIANG Renjiang,YING Yunlong,QIN Zhicheng,et al.Simulation model of zigzag grounding transformer by PSCAD[J].Value Engineering,2015,29:137-138.
[15]陈锦胜.配电线路使用PSCAD电缆模型建模[J].广东电力,2015,28(3):82-85.CHEN Jinsheng.Modeling for power distribution lines by using pscad cable model[J].Guangdong Electric Power,2015,28(3):82-85.
[16]许晔,郭谋发,陈彬,等.配电网单相接地电弧建模及仿真分析研究[J].电力系统保护与控制,2015,43(7):57-64.XU Ye,GUO Moufa,CHEN Bin,et al.Modeling and simulation analysis of arc in distribution network[J].Power System Protection and Control,2015,43(7):57-64.
[17]王倩,谭王景,叶赞,等.基于ATP-EMTP的电弧接地故障的建模及仿真[J].电网与清洁能源,2015,31(1):16-21.WANG Qian,TAN Wangjing,YE Zan,et al.Modeling and simulating of arc grounding fault based on ATP-EMTP[J].Power System and Clean Energy,2015,31(1):16-21.
[18]曾德辉.含分布式电源配电网和微电网故障分析与保护新原理研究[D].广州:华南理工大学,2016.ZENG Dehui.New protection principles of distribution network and micro grid with distributed generation[D].Guangzou:South China University of Technology,2016.