用于特高压输电线保护的能量方向元件

传统能量方向元件在特高压线路中不能正确判别故障方向,同时当线路出口发生故障时由于系统内阻很小而导致有功能量方向元件也不能做出正确的判断。提出了一种应用于特高压长距离输电线路的故障分量式能量方向元件,并且提出了相应的方向纵联保护原理,用贝瑞隆算法加以实现;从而使保护的可靠性大大提高;分析了保护判据及其动作特性。通过数字仿真证明了所提方向元件原理和保护判据的正确性和可靠性,该元件具有不受系统暂态过程、过渡电阻、串补电容等因素影响的特性,而且其灵敏度不受故障类型及故障位置等因素的影响,同时动作速度也较快,不大于20ms。

Energy directional relay applied to the protection for UHV transmission line

Traditional energy directional relay fails to discriminate fault direction in protection of the UHV long distance transmission line;and for the system resistance is too small,active energy directional relay will not work when there is fault on the outlet of transmission line.To resolve the above problems,based on fault components applied in protection of the UHV long distance transmission line,the energy directional relay was proposed,which was carried out by Bergeron algorithm,and corresponding directional pilot relay protection principle was presented.This will improve the reliability of relay protection very well.The operation criterion and action performance were discussed.The correctness and reliability of the directional protection principle and its operation criterion was proved by digital simulation.The energy directional relay,whose action speed no more than 20ms,will not be affected by transient process of the power system,fault resistance and series compensated capacitor,furthermore,its sensitivity will unaffected by the type or position of the fault.