A Novel DFR Suppression Control for the Single Phase Multi-Input based Quasi-ZSI

Abstract

Mismatched double-frequency power is existed between the dc input and ac output In single-phase photo voltaic (PV) system. In a passive network the double-frequency ripple (DFR) energy needs to be buffered. Otherwise, the ripple energy will flow into the input side and adversely affect the PV energy gather. In existed PV system, electrolytic capacitors are usually used for high capacitance. However, electrolytic capacitors are considered to be one of the most failure prone components in a PV inverter. In proposed system, a capacitance reduction control strategy is proposed to buffer the DFR energy in single-phase Z-source/quasi-Z-source inverter applications. The capacitance requirement can reduced and achieve low input voltage DFR in a proposed control method. Consequently, highly good in quality film capacitors can be used. The increased with-out using any extra hardware components. Switching device voltage stress and power loss due to the proposed control strategy will also be discussed. Simulation and experimental results are also shown to verify the proposed circuit and analysis.