A Hybrid Equivalent Model for Prediction of Power System Frequency Response

Abstract

In order to develop an enhanced equivalent model for fast and accurate prediction of power system frequency response after considerable active power imbalance, a hybrid equivalent model is proposed by combining measurement data and available model information. Measurements based model identification is employed offline to estimate the standard equivalent governor model of the power system. Equivalent governor model of the power system under the disturbance is fast derived online from the estimated standard equivalent governor model and available individual governor models. Furthermore, the hybrid equivalent model is established online based on three sub-models, i.e., equivalent rotor model, equivalent governor model and equivalent load model. Simulations on IEEE 39-bus system are presented to evaluate the accuracy, computation complexity and adaptability of the hybrid equivalent model, incorporating comparisons with popular average system frequency (ASF) model, system frequency response (SFR) model, and full model time domain simulation.