《《A Single-Phase Grid-Connected Inverter with a Power Decoupling Function》.pdf

A Single-Phase Grid-Connected Inverter with a Power Decoupling Function Fumihiro Shinjo, Keiji Wada, Toshihisa Shimizu Department of Electrical and Electronic Engineering Tokyo Metropolitan University 1-1, Minamiosawa, Hachioji, Tokyo, 192-0397, Japan Abstract— This paper presents a single-phase grid connected SX2 Lf inverter with a power decoupling circuit. In the single-phase grid SAC 1 SAC3 connected inverter, it is well known that a power pulsation with power decoupling SM2 L iAC twice the grid frequency is contained in the input power. In a con- iDC circuit s ventional inverter, electrolytic capacitors with large capacitance Cf vAC have been used in order to smooth the DC voltage. However, SX0 vX CX SX 1 SAC2 SAC4 lifetime of those capacitors is shortened by the power pulsation vDC CDC with twice grid frequency. The authors have been studied a active power decoupling method that reduce the pulsating power on LX SM 1 the input DC bus line, this enables to transfer the ripple energy appeared on the input DC capacitors into the energy in a small film capacitor on the additional circuit. Hence, extension of the Fig. 1. Main circuit configration. lifetime of the inverter can