负序方向元件在同杆双回线中的动作行为分析

Analysis of negative sequence directional element behavior in double lines on same tower

由于同杆双回线自身的特殊性,使得在常规线路保护中有着广泛应用的负序方向元件的性能受到影响。从同杆双回线的故障特点出发,利用六序故障分量法分析了负序方向元件在同杆双回线各种典型故障情况下的动作行为。结果表明,在发生ⅠBCⅡBG,ⅠBCⅡCG跨线故障时,Ⅱ回线两侧的负序方向元件有可能拒动;在发生ⅠAⅡBCG,ⅠABCⅡBCG,ⅠABCⅡAG跨线故障时,两回线路总有一回线路两侧的负序方向元件拒动。利用电磁暂态仿真软件PSCAD/EMTDC搭建同杆双回线仿真模型,仿真结果也验证了这一结论。

The performance of negative sequence directional element widely used in conventional transmission line protection may be affected when it is used in the double transmission lines on the same tower.Based on the characteristics of double lines on the same tower,the behavior of negative sequence directional element under various fault conditions of double lines on the same tower is analyzed with the six-sequence fault component method.Results show that,for the inter-line faults of ＂ⅠBCⅡBG＂ and ＂ⅠBCⅡCG＂,the negative sequence directional elements at both side of Ⅱ line may refuse to operate;for the inter-line faults of ＂ⅠAⅡBCG＂,＂ⅠABCⅡBCG＂ and ＂ⅠABCⅡAG＂,the negative sequence directional elements at both side of one line will refuse to operation.Results of simulation with PSCAD / EMTDC verify this conclusion.