摘要
为解决小电流接地系统在发生高阻接地故障时因馈线参数不对称所造成的故障选线难题,提出了一种消除不对称参数影响的故障选线方案。首先,推导了小电流接地系统中,计及不对称参数影响下的对地导纳计算公式,并对该计算公式作为选线判据的适用性进行了分析。其次,针对消弧线圈接地方式下该判据的局限性,采用了主动保护的思想,将消弧线圈接地方式改造为动态接地方式,有效放大了故障馈线与非故障馈线的对地导纳参数差异。理论分析与PSCAD仿真结果表明:故障馈线的对地导纳模值大于非故障馈线,故障馈线与非故障馈线的对地导纳相角差大于90,可依靠其差异性进行准确选线。该方案在理论上消除了不对称参数与过渡电阻对故障选线的影响。
In order to solve the fault selection problem caused by the asymmetry of feeder parameters in the occurrence of high-impedance grounding faults in small current grounding systems,a fault cable selection scheme to eliminate the influence of asymmetric parameters is proposed.Firstly,the calculation formula for ground conductivity under the influence of asymmetric parameters in the low-current grounding system is derived,and the applicability of the calculation formula as a line selection criterion is analyzed.Secondly,in view of the limitations of this criterion under the grounding method of the arc suppression coil,the idea of active protection is adopted,and the grounding method of the arc suppression coil is transformed into a dynamic grounding method,which effectively amplifies the difference between the ground conduction parameters of the fault feeder and the non-fault feeder.Theoretical analysis and PSCAD simulation results show that the modulus of the ground conduction of the fault feeder is greater than that of the non-fault feeder,and the difference between the phase angle of the ground conduction of the fault feeder and the non-fault feeder is greater than 90℃,and the accurate line selection can be carried out by relying on its difference.This scheme theoretically eliminates the influence of asymmetric parameters and transition resistance on fault line selection.
作者
伊国强
李景禄
吴泽文
YI Guoqiang;LI Jinglu;WU Zewen(Changsha University of Science&Technology,Changsha 410114,Chi)
出处
《电瓷避雷器》
CAS
北大核心
2023年第1期31-38,共8页
Insulators and Surge Arresters
基金
国家自然科学基金(编号:52177070)。
关键词
不对称参数
高阻接地
动态接地
对地导纳
asymmetric parameters
high resistance grounding
dynamic grounding
ground conduction
