互联电网保护误动行为分析

随着电网规模日益扩大，不考虑系统暂态过程影响的传统保护整定方式已不能满足维护系统稳定运行的要求，作者以川南系统和沱江电网怕互联电网的保护误动作为例，用EMTP进行仿真。定性和定量分析了该互联电网电磁暂态过程对联络变电站低压侧母联开关保护几次动作的影响，并着重分析故障后系统机电暂态过程，通过编程模拟互联电网故障后的功能特性，绘制功角－时间曲线（δ-t）和电流－时间曲线（i-t)，详细分析了短路切除后互联电网的机电暂态过程对保护动作的影响，找到了误动的根本原因，并提出了对该电网保护配置的改进措施。

ANALYSIS OF PROTECTION MALOPERATION OCCURRING IN INTERCONNECTED POWER SYSTEM

Along with the unceasing extension of the scale of power system, it is impossible to meet the need of maintaining the stable operation of power system for conventional setting mode of protective relaying without the consideration of the influences of transient processes. Taking a maloperation of protective relaying occurred in a certain interconnected power system as example, the influence of electromagnetic transient process in this interconnected system on several actions of the protective relaying for bus-tie circuit breaker at the low voltage side of an interconnection substation is simulated quantitatively and qualitatively by EMTP. Through the simulation of generator angle characteristics of intercon-nected power network with the program developed by the author the electromechanical transient process of the system after the fault occurring is emphatically analyzed. Furthermore, by means of drawing curve of generator angle d varying with time and that of current varying with time, the influence of electromechanical transient process of interconnected system on the behavior of protective relayings after the fault is switched off is analyzed in detail to find out the basic reason of protection maloperation, and the improvement measures of the configuration of protective relayings for the power network are suggested