Back-stepping Control of Three-phase Inverter for UPS Application with a Fourth-order Load Current Observer in DQ Frame

This paper investigated the back-stepping control strategy for three-phase UPS application. Internal pseudo current-loop reference and the final control reference were obtained step by step in D frame and Q frame respectively. Continually, a load current observer was designed to replace three real-world load current sensors. Finally, control hardware in the loop (HIL) system validated the effectiveness of proposed control scheme.