特高压输电线路分布电容对负序方向纵联保护的影响

Influence of Distributed Capacitance on Negative Sequence Directional Pilot Protection for UHV Transmission Lines

为消除特高压输电线路中分布电容对负序方向纵联保护的影响,文章提出一种基于贝瑞隆模型的精确补偿算法。该算法对于故障暂态和故障稳态具有同样的补偿效果,并且提高了负序方向元件在大电源、长线路条件下的保护灵敏度,解决了特高压长线路外部故障时保护误动以及双回线路一回线不对称故障时非故障线路负序方向纵联保护误动的问题。理论分析和仿真试验证明了上述补偿算法的正确性。

To eliminate the influence of distributed capacitance on negative sequence directional pilot protection, the authors propose a Bergeron model based accurate compensation algorithm. The proposed algorithm can offer the same compensation effect for capacitance current under both transient and stable operating conditions, and can improve the sensitivity of negative sequence directional pilot protection under the condition of huge power source and long transmission distance, also can solve the protection maloperation problem while the external fault of long distance UHV line occurs as well as the maloperation of negative sequence directional pilot protection for non-faulty circuit while unsymmetrical fault occurs in one of the double-circuit line on the same pole. Results of theoretical analysis and simulation validate the correctness of the proposed algorithm.