A non-isolated quasi-Z-source-based high-gain DC-DC converter

Abstract

To overcome the problems associated with Z-source-based DC-DC converters, a quasi-Z-source (QZS)-based high-gain DC-DC boost converter with switched capacitors is proposed in this work. Z-source-based DC-DC converters have problems like low-voltage gain, discontinuous input current, and high-voltage stress on the active and passive components. The proposed converter can produce a high-voltage gain of more than 10 times for a duty cycle of less than 0.5. The converter has other desirable features like reduced voltage stress across the switching components and continuous input current (CIC). It comprises a QZS cell made up of switched inductors and a voltage multiplier cell (VMC) made up of switched capacitors. The power loss analysis is done using PLECS software by incorporating the real parameters of switches and diodes from the datasheet. A hardware prototype of 200 W is developed in the laboratory to verify the working of the converter. In experimental results for an output power of 200 W, the converter is operated with a source voltage of 33 V at a duty ratio of 0.4 providing an output voltage of 395 V. The converter performance is good in open-loop conditions and is verified through experimental results.