Application of Phasor Measurement Unit on Locating Disturbance Source for Low-Frequency Oscillation

Abstract

A smart power grid is an integration of the advanced measurement, communication, computer, and control techniques. Among all the state-of-the-art technologies in building a smart power grid, the phasor measurement unit (PMU) is an important and promising one. Nowadays in China, most ultrahigh- and high-voltage buses are all equipped with PMUs. This paper reports an application of PMU data on locating the disturbance source for the low-frequency oscillation that has happened several times in the interconnected big power grids in China recently. The posterior analysis by the Electric Power System Research Institute of China (CEPRI) has confirmed that these low-frequency oscillations are caused by the resonance phenomena. It is urgent to find the disturbance source in case it happens again. However, there have been no systematic and effective methods to locate the disturbance in a very large power system. The trial and error method has been implemented via the digital simulations, but in vain. To overcome this problem, a novel method is developed in this paper to locate the disturbance source with the help of PMUs. The method takes advantage of the PMU measurements to reduce the searching area for locating the disturbance source. Case studies show the efficiency of the proposed method.