【摘要】 行波保护易受各种高频信号的影响,降低了保护的可靠性,为此,提出一种滤除高频暂态量后的突变量高速方向保护原理。理论分析表明,故障发生后的一段时间内保护安装处的电压、电流突变量在滤除高频暂态量后其极性具有故障方向特征,即正向故障时两者极性相反,反向故障时相同。基于此,构造了一种新型相序变换矩阵,使得保护原理适用于三相系统各种故障类型;该原理也适用于串补或并补线路,且不受带补偿电抗器线路中电抗器运行状态的影响。仿真结果表明,该原理能够快速、可靠地识别线路各种区内外故障,其性能不受故障电阻、故障起始角的影响,且不受串补线路电压、电流反向的影响,具有良好的工程应用前景。更多还原

【Abstract】 The performance of conventional travelling wave protection is liable to be influenced by the high frequency transient quantities, which can reduce the protection reliability. To solve this problem, this paper proposed a high-speed fault-component based directional protection algorithm. Theoretical analysis result shows that during a period of time after the fault, the directional polarities obtained from superimposed voltages and currents at the relay point can describe the fault direction after the high frequency components being filtered out. For forward faults, the supervised voltage has opposite polarity compared with that of the current; for backward faults, they have same polarities. Based on this, a novel phase-sequence transformation matrix was constructed to identify faults for three-phase systems. Sequence 1 and 2 quantities transformed by using this matrix are suitable for all fault types. The algorithm can also been applied to series-compensated or parallel-compensated transmission lines and its performance will not be influenced by operation states of shunt reactors of parallel-compensated transmission lines. Simulation results show that the scheme can quickly and reliably identify internal and external faults, and the algorithm is immune to fault resistances and fault inception angles. Its performance is also not affected by the current and voltage inversion phenomena of the series-compensated transmission lines. The scheme is feasible for actual application.更多还原