PUBLICATIONS

This paper presents an ac ripple repression method for neutral-point voltage of three-level inverter system with electrolytic capacitor

less. To reduce the volume of three-level inverter system, electrolytic capacitor with huge capacitance is must eliminated from dc-

link. In the inverter system applying film capacitors, however, the ac ripple component in neutral-point voltage of dc-link is increased

and three-phase output currents are distorted when the dc-link capacitors are small capacitance. In this paper, the dc-link shunt

compensator (DSC) is applied to compensate drawback of small capacitor systems and the offset value injection method is present

to reduce ac ripple in NPV. These two proposed process ensure the quality improvement of the input grid currents and output load

currents obviously. The feasibility of proposed method is verified by simulation results.