基于序增量功率电流方向追溯电压暂降源的方法

电压暂降已经成为最受关注的电能质量问题之一。提出一种基于序增量功率电流方向追溯电压暂降源的方法。首先以电流、电压互感器的同名端确定一个监测点的正参考方向。监测点的正序增量功率电流为正,三相对称电压暂降源位于监测点正参考方向的相同方向,即下游,反之则在上游;监测点的负序增量功率电流为正,三相不对称电压暂降源位于监测点正参考方向的相反方向,即上游,反之则在下游。仿真及实验室模拟测试都证明:所提出的追溯电压暂降源的方法能准确地追溯辐射式配电网中由各种电网故障引起的电压暂降源。该方法计算简单、运算量小,适合于单片机完成,可嵌入在继电保护器中,由保护器完成电压暂降源的追溯。

Method of Tracing Voltage Sag Source Based on Sequence Incremental Power Current Direction

Voltage sag has become one of the most concerned power quality problems. A method of tracing voltage source based on the sequence incremental power current direction is proposed. First the positive reference direction of a monitoring point is determined by its current and voltage mutual inductor corresponding terminals. If the sequence incremental power current of the monitoring point is positive, the symmetric three-phase voltage sag source is in the same direction as the positive reference direction, namely, in the downstream of the monitoring point, otherwise in the upstream. When the sequence incremental power current of the monitoring point is positive, the asymmetry sag source is opposite to the positive reference direction, namely, in the upstream of the monitoring point, otherwise in the downstream of the monitoring point. It is proved by both simulation and experiment that this voltage sag source tracing method can accurately locate the voltage sag source in a radial distribution power system regardless of fault types. Simple in calculation and asking for only a small amount of computation, this method can be realized by single-chip, or embedded in the relaying for accomplishment of voltage sag source tracing.