High Step-Up Y-Source Inverter With Reduced DC-Link Voltage Spikes

Impedance-source inverters using coupled inductors have been investigated as alternatives for providing high step-up voltages. However, leakage inductances of the coupled inductors have commonly led to lower overall effectiveness, in addition to generating high dc-link voltage spikes. The latter raises voltage stresses of switches, which in turn, may reduce the power levels of the inverters. A high step-up Y-source inverter has therefore been proposed in this paper to provide a high boost with a smooth dc-link voltage ensured by proper recycling of the leakage energy. These features have been verified by comparing simulation and experimental results of an existing Y-source and the proposed inverters. Factors compared are their respective boost ratios, voltage stresses, current stresses, and dc-link voltage spikes.