Sliding mode duty cycle control with current balancing algorithm for an interleaved buck converter-based PV source simulator

Abstract

Photovoltaic (PV) source simulators are widely used to evaluate the performance of solar inverters and study their grid integration issues in the laboratory settings. Most of the commercial PV simulators are designed based on the programmable dc power supply platform. Owing to bulky output capacitors, the dynamic response and the bandwidth of these PV simulators are significantly limited, which, therefore, cannot meet the requirements to test advanced features of the solar inverters. In this study, a cost-effective high bandwidth PV simulator is proposed. A three-phase interleaved buck converter is utilised as the power stage and a novel sliding mode duty-cycle controller with auto current balancing algorithm is proposed to ensure the accurate and fast reference tracking along with phase current balancing. Both simulation and experimental studies are carried out to validate the feasibility and effectiveness of the proposed PV source simulator.