The analysis of power losses of power inverter based on SiC MOSFETs

The power loss is an important factor to be considered in the design stage of power inverter. However, there are a few literatures to systematically analyze the power losses of power inverter, especially for with Silicon Carbide Metallic Oxide semiconductor field effect transistors (SiC MOSFET). This paper investigates the power losses of power inverter based on SiC MOSFETs by considering various factors such as junction temperature, switching frequency, dead-time, PWM modulate mode, control strategies and operation conditions of motor. It can be founded that the total power losses of power inverter are linearly risen with the increase of switching frequency and are reached to the maximum value when the motor operates at the highest speed. From the perspective of power loss distribution of power inverter, the power losses of power inverter are mainly distributed in the power modules, and the power losses of SiC MOSFET chips in the power module account for more than 93.4% of the total power losses of power inverter. It has very important significance for the thermal design, reliability evaluation and parameters selection of power inverter.