Suppression Method of DC Capacitor Currents in a Three-Phase Current Unfolding Inverter Equipped With Ultra-Small DC Capacitors

Abstract

This paper proposes a three-phase inverter using current unfolding principle. The proposed inverter is expected to raise efficiency by reducing the total number of switching compared with popular inverters. The inverter can also reduce the number and size of passive components resulting in miniaturizing the inverter size. In addition, this paper proposes the suppression method of the dc capacitor current. The suppression method enables the proposed inverter to operate with ultra-small dc capacitors. The validity of the proposed inverter is confirmed through simulation. The simulation results exhibit low current THD of 2.8% even though the proposed inverter operates with the ultra small capacitors. It is expected that the proposed inverter can achieve high efficiency and reduce the size and number of passive components at the same time.