비대칭 입력 전압 상태를 고려한 LIDVR의 새로운 제어방법

Power Quality and reliability are becoming important Issues for critical and sensitive loads The recent growth in the use of impactive and nonlinear loads has caused many power quality problems such as voltage flicks, harmonics and unbalances, which may cause the modern automatic devices to fail, misoperate, or shut down This paper deals with 7-Level H-Bridge Line- Interactive Dynamic Voltage Restorer (LIDVR) system It has the power factor near to unity under normal source voltage, can compensate the harmonic current of the load and instant interruption, and has the fast response Currently, most of the DVR design studies are based on the assumption of the balanced three-phase system But, actually line fault occurred 11φ sag or 21φ sag Hence, proposed new control scheme compensate asymmetry input voltage Finally, simulation results verify the proposed 7-Level H-Bridge LIDVR system