A Modified Single-Phase Transformerless Y-Source PV Grid-Connected Inverter

Y-source inverter can obtain a high output voltage by using a small shoot-through duty ratio and especially applies to the occasions of large range input voltage, such as photovoltaic (PV) power generation, and so on. However, traditional Y-source needs to use a low-frequency transformer to ensure galvanic isolation between the grid and PV system. In order to combine the advantages of both Y-source inverter and transformerless PV inverter, this paper proposes a modified single-phase Y-source PV grid-connected inverter and a corresponding modulation strategy. By directly connecting negative terminal of PV array to the neutral line of the grid, the proposed topology can eliminate the leakage current completely. In this paper, the operation principle and modulation strategy of the modified transformerless Y-source inverter are illustrated. Finally, a 200W laboratory prototype is built to verify the performance of the proposed topology.