Synchronous Parameter Estimation Methods for Salient Pole Generators Based on Steady State Synchrophasor Measurements

Abstract

Synchrophasor measurements are readily available at many power plants. One of the promising applications of the synchrophasor technology is real-time monitoring of power system components such as a synchronous generator (SG). The paper is dedicated to estimating hydrogenerator synchronous parameters through synchrophasor data captured under steady-state conditions. The synchronous reactances along the d- and q-axes are important to verify, as they go into equivalent circuits for steady state analysis and stability margin assessment.A few different models are developed and tested out with simulated data as well as real-field synchrophasor measurements collected at one of the Russian hydroelectric power plants. Two different approaches to measurement error modeling have been taken, and the results on simulated data turned out fairly good, with the standard deviation for xd of less than 1 %, and for xq of at most 4 %. For a "black box" simulation, five different operating states captured by a phasor measurement unit on a real hydrogenerator were selected and used as input data to the developed models. The result for the xd synchronous reactance was acceptable while for xq was not. Possible ways to make the estimation results more accurate and robust are suggested.