Optimal Control of Grid Connected Electric Railways to Mitigate Low Frequency Oscillations

Abstract

This paper presents mitigation of grids' low-frequency oscillations is carried in presence of railway traction load. In order to better deal with these low frequency oscillations, this study has considered the vehicle-grid cascade system. The numerical study of the single-machine infinite bus (SMIB) system has evaluated the influence of electric traction vehicle (ETV) by establishing overall small signal model of the grid connected vehicle. The performance of the system is compared for ETV-connected SMIB and ETV-connected SMIB equipped with linear quadratic regulator (LQR) controller. It is observed that modified SMIB power system with LQR-based control is superior to others in improving system responses with significantly reduced settling time, rise time, and peak overshoot.