Modeling of Power Module for 48 V High Power Inverter

The paper presents simulation and measurement results of high current three-phase inverter power modules used in 48 V motor applications. Firstly, FEM (Finite Element Method) is used to extract circuit parasitics. With the inclusion of MOSFET and parasitic component SPICE models, a highly accurate simulation model is created. Switching characteristics of the power modules are simulated at 300 A load current and 48 V battery voltage. Thermal simulations estimate maximum transistor temperatures at given power losses. Electrical simulations are compared to actual measurements under identical test conditions. The comparison shows good matching between simulations and measurements. The phase voltage rise and fall times are the same in simulations and measurements. The overshoot voltages are also the same in both cases, at around 28 V. The mismatch can be found in the currents of secondary loops. The gate voltage signal is similar with small mismatch of Miller plateau voltage, due to transistor model parameters mismatch.