Frequency response modeling and equivalent inertial estimation of induction machine

Abstract

With the rapid development of renewable energy and High Voltage Direct Current (HVDC), the power system is turning to be a low-inertia system. Due to insufficient inertia on the power side, the proportion of inertia on the load side increases. The frequency support ability of the induction machine in the inertial time scale needs to be investigated. The purpose of this paper is to analyze the time-varying characteristics of the effective inertia of induction machine and to estimate the frequency support ability of induction machine. In this paper, the induction machine model in electromechanical transient process is established, and its transfer function is deduced by using small-signal model, and the time-varying characteristics and affecting factors of the induction machine’s inertia on the grid are analyzed. Besides, an evaluation model of the equivalent inertia of induction machine is proposed to quantify the inertial support ability of dynamic loads, and the frequency support ability of the model and the dynamic characteristics of induction machine are analyzed. Finally, the simulation model is conducted on MATLAB/Simulink platform to verify the correctness and effectiveness of the model proposed in this paper.