利用基波相量变化率的快速选相方法

针对目前选相方法不能快速、可靠识别所有故障类型的问题,提出了利用基波相量变化率的故障选相方法。线路发生短路故障后,故障相基波电流相量变化率受衰减直流分量及工频故障分量影响,其值迅速增大,而非故障相基波电流相量变化率变化较小;如果发生接地故障,零序电流基波相量变化率受衰减直流分量及工频故障分量影响,其值也会迅速增大,否则其值在零附近波动。依据不同类型故障中基波电流相量变化率的特征能够快速、可靠识别故障相。利用PSCAD/EMTDC仿真数据对算法进行测试,仿真结果表明:算法能够在故障后四分之一周波内准确判断故障相,具有较高可靠性。

A Fast-Speed Phase Selection Method Based on the Change Rate of Fundamental Current Phasor

In view of the problem that the existing fault phase identification methods can ’ t identify all fault types quickly and reliably , the phase selection method based on change rate of fundamental current phasor is proposed in this paper .When the short-circuit fault occurs , the change rate of fundamental current phasor of faulty phase , which is affected by the decaying DC component and the fundamental frequency fault component , increases rapidly , and that of non-faulty phase is small .If grounding fault occurs , the change rate of fundamental current phasor of zero sequence current is affected by the decaying DC component and the fundamental frequency fault component and increases rapid -ly;otherwise , its value is near zero .Then , the faulted phases can be identified quickly and reliably according to the characteristics of the change rate of fundamental current phasor under various conditions .The simulation data from PSCAD/EMTDC is applied to verify and test the proposed algorithm , the simulation results show that the algorithm which has high reliability can identify any types and phases of faults in a quarter cycle .