A lifetime improved single phase grid connected photovoltaic inverter

In this paper, a reliable low power single phase grid-connected inverter for photovoltaic modules is proposed. The inverter has improved lifetime since large electrolytic capacitor is replaced with small film capacitor due to circuit topology, power processing and proper control scheme. Thus the main limiting component in single phase grid connected inverters is obviated. The proposed inverter consists of two power processing stages. First a dual active bridge (DAB) converter boosts the voltage of PV panel to approximately 440 V and eliminates impact of high dc bus voltage ripples. A proper feed forward control is proposed to regulate the dc bus voltage with high ripple. Simulation results prove that obviating large electrolytic capacitor has no effect on utilization factor of photovoltaic modules.