Thermal Analysis and Comparison of Common-Ground Voltage Source Inverter

Abstract

Non-isolated inverters have gained popularity in low-power renewable applications. Among these, the common-ground inverter has the advantage of eliminating leakage currents and common-mode voltages by bypassing the parasitic capacitance. Many of the common-ground topologies have a higher number of switching and passive components in comparison to the commonly used H-bridge voltage source inverter (HB-VSI). Nevertheless, there exists a few common-ground voltage source inverters (CG-VSIs) that have a similar number of components. However, it is necessary to analyze the power losses and thermal behavior of the CG-VSI and compare the chances of failure in comparison to the conventional HB-VSI. This paper presents the switch stress, power loss, and thermal analysis of the switching devices in a CG-VSI that has the same number of components and a similar configuration as the HB-VSI. The simulations are performed on the PLECS software for different loads and switching frequencies. The results indicate that each of the switches of the CG-VSI has different stresses, power losses, and thermal characteristics. Furthermore, the thermal behavior of switches in the considered CG-VSI can be comparable if the switches are chosen appropriately.