Locating Method of Disturbance Source of Low Frequency Oscillation Based on Oscillation Phase Difference

Abstract

Fast and accurate location of low frequency oscillation disturbance source is crucial to the safe and stable operation of power system. This paper firstly analyzes the mechanism that how the disturbance source unit influence the other units in the power grid. Then, the oscillation phase distribution relation of the points in the tie-line is derived based on the simplified model of two machine oscillation and the method for locating the disturbance source is proposed based on the oscillation phase difference. The empirical mode decomposition is used to extract the electric quantity data of the dominant oscillation mode and the Hilbert Transform is used to calculate the oscillation phase with physical meaning. The oscillation phase difference is calculated to describe the oscillation phase relationship between two points. The orientation of the disturbance source can be traced by the network information criterion and the specific disturbance unit can be located by the local information criterion of the power plants. The principle of this method is clear and only one kind of electric quantity is involved in calculation. Finally, this paper verifies the applicability of this method by the low frequency oscillation simulation of one actual power grid. The results show that this method is of good accuracy and has potential value of engineering application.