Advanced Control Approach Based on a Super-Twisting Sliding Mode for a Cascade Voltage and Current Control Topologies of a Grid-Supporting Grid-Forming Power Converters

Abstract

This paper introduces advanced control strategies for power electronic converters in distributed generation systems, specifically designed for islanding microgrid systems. The proposed methodology employs a non-linear Sliding Mode Control (SMC) approach, specifically utilizing the Super-Twisting Algorithm (STA) for the regulation of power converters in the Grid-Supporting Grid-Forming (GSGFm) mode. A cascaded control scheme with an outer-loop voltage controller and an inner-loop current controller utilizes a STA method implemented in the Synchronous Rotating Reference Frame (SRRF). The main advantage of the proposed SMC-STA algorithm in the cascade control methodology is its simple structure and easy implementation. The HIL test under normal conditions typically involves analyzing both transient and steady-state behavior when supplying energy to the load. The stability of both voltage and current is compared between the two control strategies. The experimental results provide confirmation of the control performance of the proposed control methodology based on the STA method. The results demonstrate that the STA-based control methodology effectively regulates voltage levels and minimizes fluctuations, surpassing the performance of a classical PI controller.