Inverter Voltage Drop Characterisation Considering Junction Temperature Effects

This paper presents an experimental based inverter voltage drop characterization method considering the thermal effects which is usually neglected in the existing literature. This characterization leads to forming an inverter voltage drop model which consists of linear and nonlinear terms. The temperature effects on these terms are modeled by two separate temperature coefficients α and β derived from several experimental data. The proposed model provides accurate inverter voltage drop as a function of measured instantaneous phase current and junction temperature. This voltage drop can be used to accurately compensate the inverter voltage drop in several control and estimation purposes. The experimental characterization is performed in this paper for a two level voltage source inverter with IGBT power modules. Finally, the inverter voltage drop from the characterized model is validated by measurements.