Super-Twisting Double Integral Sliding Mode Control For a Grid-Connected Three-Phase Inverter

Abstract

Grid-connected inverters (GCI) play a crucial role in injecting DC power from renewable resources into the utility grid; moreover, the current quality largely depends on the effectiveness of the adopted control strategy. This paper proposed a novel super-twisting double integral sliding mode control (SMC) algorithm for a three-phase grid-connected inverter with an LCL filter. In this study, the control algorithm is first derived based on the system’s dynamic mathematical model. Then, extensive simulation studies are carried out in MATLAB and Simulink software to validate its performance. Furthermore, the controller effectiveness is rigorously assessed under challenging conditions, including a 400% grid impedance variation, a 66% system parametric variation, grid frequency variation, and higher-order grid harmonic components. Under the worst-case scenario, the total harmonic distortion (THD) value of the grid current remains under 2.6%, demonstrating the proposed controller’s robustness.