Extended quasi-Y-source inverter with suppressed inrush and leakage effects

The Y-source inverter uses different turns ratios of a coupled inductor and a controllable duty ratio to vary its gain. However, its input current is discontinuous, and any leakage inductances of its coupled inductor will lead to unintentional dc-link voltage spikes and gain reduction. To solve these problems, an extended quasi-Y-source inverter has been proposed in this study, which compared with the Y-source inverter, uses an extra inductor and an extra capacitor. Although the extras may not appear attractive, they have successfully helped with the suppression of leakage effects, which decrease the voltage spikes, and hence permit the main magnetic core size to be much smaller. Concurrently, the continuous input current can be also achieved. Besides, inrush current at startup has been reduced to a more acceptable value, which together with other features of the proposed inverter, have been proven through experiments.