Applying Adaptive Super-Twisting Controller for Voltage Regulation in a DC Micro Grid

Abstract

Micro grids mainly operate in two modes of on-grid and off-grid. The main problems regarding off-gird are voltage and frequency oscillation or instability. In this case, a control system must be used to adjust the voltage and frequency of the micro grid. According to nonlinear features, uncertainty parameters and variations of the load, applying nonlinear and robust methods will be a suitable approach for the system. In this paper, a nonlinear adaptive super-twisting controller based on the sliding mode theory is used to control the micro grid. The principal reason for utilizing this controller is to control distortion in presence of parameters uncertainty. For this purpose, system dynamic equations will be extracted. Afterwards, by using sliding mode theory, a controller will be designed to control the entire system. To address chattering problem, an adaptive super-twisting method is proposed. Closed loop stability has been proved by Lyapunov theorem. The proposed method is evaluated by MATLAB/Simulink software, and a comparison between the simulation results and the other methods has been made. The comparison studies show that the proposed adaptive Super-Twisting controller is more applicable than conventional methods.