Power loss investigation in low power current source inverters using wideband gap devices for solar energy applications

Abstract

With the steady expansion of renewable energy comes the need to develop next-generation power converters focusing on high power density, efficiency, and reliability with lowered costs, simple structure, and the ability to meet strict grid codes. Currently, Voltage Source Inverter (VSI) based solutions dominate the solar inverter market, however, the Current Source Inverter (CSI) introduces some interesting advantages making the topology a valued research area. These advantages include inherent short circuit protection, natural voltage boosting capabilities, increased reliability, and increased power density. However, CSIs suffer from significant conduction losses due to the need for reverse voltage blocking or “reverse blocking” (RB) semiconductors and a large DC-link inductor with high losses. It is speculated that Wide Bandgap (WBG) devices will push power converters to the “next generation”. Although, the magnitude of WBG device advantages will depend on the ability of commercially available devices to harness the benefits of WBG material, as well as the converter configuration. With the roll-out of commercially available WBG devices, their advantages should be able to naturally improve the base CSI’s efficiency through a reduction in the RB switch’s conduction and switching losses. Also, by enabling higher switching frequency operation, passive components can be downsized. This alleviates the DC-link inductor size, cost, and power loss technical challenges seen in the CSI topology by a factor to be studied. [...]