基于扰动功率的电压暂降源方向判断

A Direction Finder for Voltage Sag Source Based on the Disturbance Power Direction

电压暂降源定位,就是确定引起电压暂降的扰动源位于监测装置的哪一侧。从引起电压暂降的主要扰动电力系统故障的分析入手,应用线性电路的叠加原理,得到电网故障过程中在扰动电压的激励下,扰动有功功率流的方向可准确定位电压暂降源的结论。扰动功率为正时,扰动源在监测点的上游;扰动功率为负时,扰动源在监测点的下游。给出扰动功率的算法。仿真实验证明:所提出的暂降源定位方法能准确定位由各种电网故障引起的电压暂降,适用于任何网架结构电网(辐射式、环式、单回路、双回路、单电源、多电源)及不同中性点接地方式组成的混合电网,也适用于其它扰动(如:大电机启动等)源的定位。

Voltage sag source location is to determine the disturbance origins＇ relative position of monitoring device. By analyzing power system faults, which is the main reason resulting in the voltage sags, the direction of the disturbance power has been found to be a good indicator of the sag source location. If the disturbance power measured at the monitoring point is positive, a disturbance origin is located at upstream, and if the disturbance power measured at the monitoring point is negative, a disturbance source is located at downstream. The calculation methods of the disturbance power are presented respectively. The simulation tests show that the proposed method has a high effectiveness in voltage sag source location caused by all kinds of faults. The new method is suitable for any power grid structure （radial type, ring type, one-source, multi-source, etc.）, and can also be used in locating other disturbance sources （E.g.： large motor starting, capacitor switching etc.）.