基于最小均方时延估计法的强迫功率振荡扰动源定位方法

摘要

当电网发生强迫功率振荡时，快速找到扰动源并将其切除，对保障电网的安全稳定运行具有重要意义。电网中强迫功率振荡引起的机电扰动会沿着输电线路在电网中传播，根据传播到不同位置的扰动波形具有时间延迟的特点，提出了一种利用最小均方时延估计法定位扰动源的方法。利用二次差分法检测强迫功率振荡起振后，通过计算关键母线频率出现扰动波形的时差和先后次序，分析扰动传播的顺序，从而确定扰动源的位置。该方法只需要广域测量信息，可以实现在线应用。四机两区域系统算例和华中电网算例均验证了该方法的有效性。%When forced power oscillation occurs in a power system,location and elimination of disturbance sources is of great significance for the secure and stable operation of the system.The electromechanical disturbance caused by the forced power oscillation travels along the transmission line.According at the time delay characteristics of disturbance waveforms at different locations,a novel method for locating disturbance sources using the least mean square(LMS)time delay estimation method is proposed.In this method,the starting of forced power oscillation is tested by the second-order difference method,and the travelling sequence of the disturbance is obtained by calculating the time delay of the disturbance waveforms at different buses, thus the disturbance source is located according to the sequence.The proposed method only needs the wide area measured data and is capable of on-line application.The validity of the proposed approach is verified by simulation results of a four-machine two-area power system and in the Central China power grid.