主变空载合闸引起的电缆护层过电压分析
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摘要
变压器空载合闸过程中由于电磁振荡产生过电压,若系统中存在高压电缆,电缆内部过电压耦合到电缆护层造成护层上电压较高,护层过电压与电缆布置方式和护层接地方式有关。文中针对白莲河抽水蓄能电站主变空载合闸时,电缆端部有异常放电声,并可见放电火花的现象,对主变空载合闸时系统产生的过电压进行测量,并对放电现象进行观测;同时采用ATP/EMTP软件计算空载合闸过电压耦合到电缆护层上的过电压大小。测量结果表明:空载合闸时主变侧过电压值并不大,进而计算得到放电处护层过电压最大值为21.49 kV,频率在600 kHz以内,大于过电压保护器动作电压,高频电流注入地网造成电缆支架处地电位升击穿其和护层绝缘间空气间隙。
In the process of transformer no-load closing,overvoltage appeared due to electromagnetic oscillation,if there are high voltage cables in the system,internal overvoltage can couple to the cable sheath which results in sheath's high voltage,and this voltage is related to cable arrangement and sheath grounding method.This article aim at the abnormal discharge phenomena in cable ends of Bailianhe Pumped Storage Station when transformer closes in no-load situation,transformer no-load closing overvoltage is measured,discharge phenomena is observed,and ATP/EMTP software is adopted to calculate cable sheath overvoltage coupled by no-load closing overvoltage.Measurement results show that the no-load closing overvoltage of main transformer is not high,then calculation results show that cable sheath overvoltage in the discharge place is 21.49 kV,with the maximum frequency 600 kHz,which is greater than the arrester operation voltage,this high frequency current flowing into the ground results in ground potential rising at cable bracket,which cause the air gap between the cable sheath insulation and cable bracket breaking down.
In the process of transformer no-load closing,overvoltage appeared due to electromagnetic oscillation,if there are high voltage cables in the system,internal overvoltage can couple to the cable sheath which results in sheath's high voltage,and this voltage is related to cable arrangement and sheath grounding method.This article aim at the abnormal discharge phenomena in cable ends of Bailianhe Pumped Storage Station when transformer closes in no-load situation,transformer no-load closing overvoltage is measured,discharge phenomena is observed,and ATP/EMTP software is adopted to calculate cable sheath overvoltage coupled by no-load closing overvoltage.Measurement results show that the no-load closing overvoltage of main transformer is not high,then calculation results show that cable sheath overvoltage in the discharge place is 21.49 kV,with the maximum frequency 600 kHz,which is greater than the arrester operation voltage,this high frequency current flowing into the ground results in ground potential rising at cable bracket,which cause the air gap between the cable sheath insulation and cable bracket breaking down.
引文
[1]陈意龙.牵引变压器投切过程的暂态分析[D].北京:北京交通大学,2011.CHEN Yilong.Analysis on the transient course of traction transformer in the switching proces[D].Beijing:Beijing Jiaotong University,2011.
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[3]傅伟,赵莉华,梁勇,等.多台变压器空载合闸励磁涌流及其抑制方案的研究[J].电力系统保护与控制,2015,6(1):28-33.FU Wei,ZHAO Lihua,LIANG Yong,et al.Study on noload closing inrush current of transformer group and suppression measures[J].Power System Protection and Control,2015,6(1):28-33.
[4]李振强,谷定燮,戴敏.特高压空载变压器谐振过电压和励磁涌流分析及抑制方法[J].高电压技术,2012,38(2):387-392.LI Zhenqiang,GU Dingxie,DAI Min.Analysis and suppression method of no-load ultra high voltage transformer resonance overvoltage and inrush current[J].High Voltage Engineering,2012,38(2):387-392.
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[7]牛海清,王晓兵,刘毅刚,等.高压单芯电缆金属护套雷电过电压仿真和参数分析[J].高电压技术,2009,35(4):784-789.NIU Haiqing,WANG Xiaobing,LIU Yigang,et al.Simulation and parameter analysis of sheath lightning overvoltage of single-core cable[J].High Voltage Engineering,2009,35(4):784-789.
[8]聂世民.单芯交联聚乙烯电力电缆金属护层感应电压限制措施研究[D].天津:天津大学,2011.NIE Shiming.Study on limiting measures of metallic sheath induced voltage of single-core XLPE power cables[D].Tianjin:Tianjin University,2011.
[9]倪欣荣,马宏忠,王东海,等.电缆护层电压补偿与护层电流抑制技术[J].电力系统自动化,2007,35(5):65-69.NI Xinrong,MA Hongzhong,WANG Donghai,et al.Techniques of voltage compensating and circulating current restraining of the metal shield for power cables[J].Automation of Electric Power System,2007,35(5):65-69.
[10]陈姝敏,杨兰均,张乔根,等.110 kV电缆护层连接方式对护层过电压的影响[J].高电压技术,2006,32(3):37-39.CHEN Shumin,YANG Lanjun,ZHANG Qiaogen,et al.Effect of sheath-bonding method on induced overvoltages in110 kV XLPE cable system in the case of ground fault surge[J].High Voltage Engineering,2006,32(3):37-39.
[11]王东海.电缆改造引起的护层感应电压变化及其补偿[D].天津:河海大学,2005.WANG Donghai.The variation and compensation of induced voltage in the metal sheath for the power cable renovation[D].Tianjing:Hohai University,2005.
[12]林集明,王晓刚,班连庚,等.特高压空载变压器的合闸谐振过电压[J].电网技术,2007,31(2):5-10.LIN Jiming,WANG Xiaogang,BAN Liangeng,et al.Resonance overvoltage caused by energizing no-load transformers in 1 000 kV AC transmission system[J].Power System Technology,2007,31(2):5-10.
[13]MORK,B A,STUEHM,D L.Application of nonlinear dynamics and chaos to ferroresonance in distribution systems[J].IEEE Transactions on Power Delivery,1994,9(2):1009-1017.
[14]孙友群.哈大电气化铁路牵引站变压器空载合闸过电压的研究[D].北京:清华大学,2004.SUN Youqun.Study on no-load closing overvoltage of transformer in traction substation of Ha-da electric railway[D].Beijing:Tsinghua University,2004.
[15]GUSTAVSEN B,BREDE A P,TANDE J O.Multivariate analysis of transformer resonant overvoltages in power stations[J].IEEE Transactions on Power Delivery,2011,26(4):2563-2572.
[16]高强.电气化铁路27.5 kV电缆金属护层雷击感应电压特性的研究[D].成都:西南交通大学,2015.GAO Qiang.Research of lightning induced voltage charactiristics on metal sheath of electrified railway 27.5 kV cable[D].Chengdu:Southwest Jiaotong University,2015.
[17]电力工程电缆设计规范:GB 50217-2007[S].2008.Cabledesignspecificationsinpowerengineering:GB50217-2007[S].2008.
[18]BRANDWAJN V,DONNEL H W,DOMMEL I I.Matrix representation of three-phase n-winding transformers for steady-state and transient studies[J].IEEE Transactions on Power Apparatus&Systems,1982,PAS-101(6):1369-1378.
[19]BASTARD P,BERTRAND P,MEUNIER M.Atransformer model for winding fault studies[J].IEEETransactions on Power Delivery,1994,9(2):690-699.
[20]连晓东,刘云鹏,陈洁.两种金属护层接地电缆仿真模型的比较[J].重庆工学院学报(自然科学版),2009,23(2):166-169.LIAN Xiaodong,LIU Yunpeng,CHEN Jie.Comparison of two simulation models on cable's sheath grounded in ATP[J].Journal of Chongqing Institute of Technology(Natural Science),2009,23(2):166-169.
[21]交流电气装置的接地:DLT 621-1997[S].2000.Grounding for AC electrical installations:DLT 621-1997[S].2000.
[2]刘春梅.变压器空载合闸涌流抑制的研究[D].沈阳:沈阳工业大学,2011.LIU Chunmei.Study on inrush restraining technology of energizing no-load transformer[D].Shenyang:Shenyang University of Teehnology,2011.
[3]傅伟,赵莉华,梁勇,等.多台变压器空载合闸励磁涌流及其抑制方案的研究[J].电力系统保护与控制,2015,6(1):28-33.FU Wei,ZHAO Lihua,LIANG Yong,et al.Study on noload closing inrush current of transformer group and suppression measures[J].Power System Protection and Control,2015,6(1):28-33.
[4]李振强,谷定燮,戴敏.特高压空载变压器谐振过电压和励磁涌流分析及抑制方法[J].高电压技术,2012,38(2):387-392.LI Zhenqiang,GU Dingxie,DAI Min.Analysis and suppression method of no-load ultra high voltage transformer resonance overvoltage and inrush current[J].High Voltage Engineering,2012,38(2):387-392.
[5]HOPKINSON R H.Ferroresonance during single-phase switching of 3-phase distribution transformer banks[J].IEEETransactions on Power Apparatus&Systems,1965,84(4):289-293.
[6]郭兴军,牛海清,王晓兵,等.高压单芯电缆护套操作过电压计算及冲击试验[J].高电压技术,2007,33(10):147-150.GUO Xingjun,NIU Haiqing,WANG Xiaobing,et al.Calculation and test of sheath overvoltage of single-core cable[J].High Voltage Engineering2007,33(10):147-150.
[7]牛海清,王晓兵,刘毅刚,等.高压单芯电缆金属护套雷电过电压仿真和参数分析[J].高电压技术,2009,35(4):784-789.NIU Haiqing,WANG Xiaobing,LIU Yigang,et al.Simulation and parameter analysis of sheath lightning overvoltage of single-core cable[J].High Voltage Engineering,2009,35(4):784-789.
[8]聂世民.单芯交联聚乙烯电力电缆金属护层感应电压限制措施研究[D].天津:天津大学,2011.NIE Shiming.Study on limiting measures of metallic sheath induced voltage of single-core XLPE power cables[D].Tianjin:Tianjin University,2011.
[9]倪欣荣,马宏忠,王东海,等.电缆护层电压补偿与护层电流抑制技术[J].电力系统自动化,2007,35(5):65-69.NI Xinrong,MA Hongzhong,WANG Donghai,et al.Techniques of voltage compensating and circulating current restraining of the metal shield for power cables[J].Automation of Electric Power System,2007,35(5):65-69.
[10]陈姝敏,杨兰均,张乔根,等.110 kV电缆护层连接方式对护层过电压的影响[J].高电压技术,2006,32(3):37-39.CHEN Shumin,YANG Lanjun,ZHANG Qiaogen,et al.Effect of sheath-bonding method on induced overvoltages in110 kV XLPE cable system in the case of ground fault surge[J].High Voltage Engineering,2006,32(3):37-39.
[11]王东海.电缆改造引起的护层感应电压变化及其补偿[D].天津:河海大学,2005.WANG Donghai.The variation and compensation of induced voltage in the metal sheath for the power cable renovation[D].Tianjing:Hohai University,2005.
[12]林集明,王晓刚,班连庚,等.特高压空载变压器的合闸谐振过电压[J].电网技术,2007,31(2):5-10.LIN Jiming,WANG Xiaogang,BAN Liangeng,et al.Resonance overvoltage caused by energizing no-load transformers in 1 000 kV AC transmission system[J].Power System Technology,2007,31(2):5-10.
[13]MORK,B A,STUEHM,D L.Application of nonlinear dynamics and chaos to ferroresonance in distribution systems[J].IEEE Transactions on Power Delivery,1994,9(2):1009-1017.
[14]孙友群.哈大电气化铁路牵引站变压器空载合闸过电压的研究[D].北京:清华大学,2004.SUN Youqun.Study on no-load closing overvoltage of transformer in traction substation of Ha-da electric railway[D].Beijing:Tsinghua University,2004.
[15]GUSTAVSEN B,BREDE A P,TANDE J O.Multivariate analysis of transformer resonant overvoltages in power stations[J].IEEE Transactions on Power Delivery,2011,26(4):2563-2572.
[16]高强.电气化铁路27.5 kV电缆金属护层雷击感应电压特性的研究[D].成都:西南交通大学,2015.GAO Qiang.Research of lightning induced voltage charactiristics on metal sheath of electrified railway 27.5 kV cable[D].Chengdu:Southwest Jiaotong University,2015.
[17]电力工程电缆设计规范:GB 50217-2007[S].2008.Cabledesignspecificationsinpowerengineering:GB50217-2007[S].2008.
[18]BRANDWAJN V,DONNEL H W,DOMMEL I I.Matrix representation of three-phase n-winding transformers for steady-state and transient studies[J].IEEE Transactions on Power Apparatus&Systems,1982,PAS-101(6):1369-1378.
[19]BASTARD P,BERTRAND P,MEUNIER M.Atransformer model for winding fault studies[J].IEEETransactions on Power Delivery,1994,9(2):690-699.
[20]连晓东,刘云鹏,陈洁.两种金属护层接地电缆仿真模型的比较[J].重庆工学院学报(自然科学版),2009,23(2):166-169.LIAN Xiaodong,LIU Yunpeng,CHEN Jie.Comparison of two simulation models on cable's sheath grounded in ATP[J].Journal of Chongqing Institute of Technology(Natural Science),2009,23(2):166-169.
[21]交流电气装置的接地:DLT 621-1997[S].2000.Grounding for AC electrical installations:DLT 621-1997[S].2000.