Resolving Loss Discrepancy between Calculation and Measurement in a 4.5 kW GaN-based Inverter

The paper aims to resolve the converter loss discrepancy between calculation and testing results by considering five factors: impacts of parasitic capacitance on switching loss, parameter variation of devices, time-varying power dissipation and junction temperature, thermal modeling using Finite Element Analysis, and some practical issues of the passive components. A 4.5 kW hard-switching inverter prototype using GaN devices was used as an example to demonstrate the improvement of loss model. The results show that after considering the above factors, loss discrepancy reduces from 35.7 W (35%) to 1.4 W (4%) at heavy load and, from 3.9 W (28%) to 2.6 W (less than 16%) at light load.