Design of Time Delay Compensator of Three-Level Inverter for Three-Phase UPS Systems

3상 UPS용 3레벨 인버터의 시지연 보상기 설계

The inevitable calculation time delay of digital controller especially degrades the voltage control performance of three-phase UPS systems. This paper proposes time delay compensators based on the Smith-predictor for both voltage and current controllers of three-level NPC inverters. The PSIM-based simulation results show that the proposed controller with delay compensator gives improved voltage control performance with respect to time delay.