An Improved Y-Source Inverter with Continuous Input Current

Compared to the traditional voltage-source inverters (VSIs) and current-source inverters (CSIs), impedance source inverters have many advantages, such as a simple structure, high voltage gain, and high reliability to avoid the short-circuit or open-circuit problems of the inverter bridge due to EMI. Among them, the most typical topology is the Y-source inverter (YSI), which obtains various voltage gain by applying different turns ratio of coupled inductors and shoot-through duty ratio. However, the input current of the traditional YSI is discontinuous and the inrush current is induced when start up. To address above issues, an improved Y-source inverter is proposed in this paper. Compared to traditional YSI, the improved YSI can suppress the inrush current at start up and reduce magnetic core size. Additionally, the higher modulation index can also be obtained with same boost ratio. The theoretical analysis has been presented and corroborated by simulation and experimental results from a 200W laboratory prototype.