Power Loss Investigation of Switch Configurations Using Wide Bandgap Devices in 10kW Current Source Inverters for Solar Applications

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. The current source inverter (CSI) is an interesting topology for photovoltaic (PV) energy applications due to its natural boosting capability, increased reliability through the reduction in DC-link capacitor size, and inherent short circuit protection. However, CSIs suffer from significant conduction losses due to the need for reverse voltage blocking semiconductors and a large DC-link inductor with high losses. With the rollout of commercially available wide band gap (WBG) devices, these drawbacks can be mitigated. Therefore, this paper explores the loss distribution and efficiency of six switch configurations based on conventional Si and WBG solutions through PSIM thermal module simulations. The method used to size the DC-link inductor is discussed, and equations for computing the losses are reviewed. The optimum switching frequency range for each configuration is determined. Finally, the loss distribution at different ambient temperatures is discussed.