Reduction of DC-link capacitance for single-phase transformerless PV power conditioning systems

摘要

In this paper, a transformerless photovoltaic (PV) power conditioning system (PCS) based on the AC/DC boost inverter is proposed, which is capable of solving leakage currents and second-order power ripple issues. In this topology, the leakage current is reduced significantly since most of common-mode currents flow through the output capacitor instead of parasitic capacitors and grounding resistor. In addition, the inherent power ripple in the single-phase inverter is eliminated without any additional components. Therefore, the bulky electrolytic capacitors can be replaced by small film capacitors. The simulation results have verified the validity of the proposed topology.