Robust Generalized Super-Twisting Sliding Mode Control Design for Optimal Performance in Three-Phase Grid-Connected Photovoltaic Systems

This article introduces a third-order super-twisting sliding mode control (Gen-STSMC) algorithm designed for the secure operation of a grid-connected photovoltaic (PV) system. The improved method changes the traditional super-twisting sliding mode control (STSMC) technique by incorporating both a linear term and a higher power term to reduce convergence time and chattering effects. This strategy generates the optimal control signals to regulate the output power of the PV system by compensating the state-dependent uncertainties using the linear and growing term. The controller's stability analysis is conducted to demonstrate its rapid convergence compared to PI and conventional STSMC scheme. A comparative simulation study against PI and STSMC is conducted to showcase the controller's rapid convergence and robust performance in various grid-connected PV system scenarios. Experimental tests are also performed to validate the controller's effectiveness in maintaining stable power generation in the presence of environmental fluctuations and DC link voltage variations.