An Improved Single-Phase Y-Source Inverter with Continuous Input Current and Reduced Effects of Leakage Inductances

The Y-source inverter has a high voltage gain by using a small shoot-through duty ratio, so it is very suitable for photovoltaic (PV) systems. However, the input current of the traditional Y-source inverter is discontinuous, and the leakage inductances in the coupling inductor lead to dc-link voltage spikes and reduce the dc-link voltage. To address these issues, an improved Y-source inverter topology is proposed in this paper. The improved Y-source inverter provides continuous input current and a higher voltage gain by adding one additional inductor and one capacitor. Compared to the traditional Y-source inverter, the improved Y-source inverter has lower voltage spikes and higher dc-link voltage. Moreover, the proposed inverter can suppress resonant current at startup. In this paper, the operating principles and effects of the leakage inductances are analyzed. Finally, a 200 W laboratory prototype is built based on a TMS320F2812 digital signal processor to verify the performance of the improved inverter. (C) 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.