무정전전원장치의 병렬운전 제어기법에 관한 연구

The parallel operation system of UPS IS used to Increase reliability of power source at critical load But parallel UPS system has a few defects, Impedance IS different from each other and circulating current occurs between UPSs, due to line Impedance and parameter variation, though controlled by the same synchronization signal According to such characteristic of parallel UPS, balanced load-sharing control IS the most Important technique m parallel UPS operation In this paper, a novel power deviation compensation algorithm IS proposed it is composed of voltage controller to compensate power deviation that be calculated by using active and reactive current deviation between inverters on synchronous d-q reference frame.