A Transformer Less Two-Stage Three-Port Power Converter with Battery Storage for PV Systems

In this paper a transformer less two-stage threeport power converter (TTTPC) with battery storage for photo voltaic (PV) systems is proposed. To address the intermittence of the PV source and to supply uninterrupted power to the load an additional battery storage unit is integrated to the proposed system with a novel front-end three-port converter. The control pulses to the converter are generated based on the decision from mode selector namely: PV to battery (Sepic converter), PV to DC bus (boost converter), PV to both battery and DC bus (Buck and boost converter, respectively), and battery to DC bus (Zeta converter). Further, a six switch five-level inverter is integrated to drive the AC loads at reduced leakage current, lower harmonic distortion and higher efficiency. Performance of the TTTPC under different modes of operation is carried out by using Matlab/Simulink.