防止过负荷时距离保护误动新判据

A New Criterion on Distance False Protection for Preventing Overloading

利用相间短路过渡电阻为数值很小的电弧电阻这一特点,提出了一种防止过负荷时距离保护误动的新判据。该判据将相间短路和接地短路分开研究,提高了距离保护Ⅲ段抗过负荷能力,有效防止了过负荷引起距离保护Ⅲ段误动,并利用PSASP对500 k V系统进行仿真,仿真结果与理论分析一致。

Based on the feature that the transition resistance is small arc resistance in phase-to-phase short circuit,this paper proposes a new criterion of distance protection for preventing overloading. The criterion separating phase-to-phase short-circuit and grounding short-circuit improves counter-overload capacity of distance protection Ⅲ and effectively prevents mal-operation of distance protection caused by overload. The simulation study of 550 k V system is conducted by using PSASP,the experimental results agrees well with the theoretical analysis.