PWM-Induced Losses Estimation in Electrical Motor Driven with GaN-Based Inverter

High-performance switches such as Gallium Nitride (GaN) devices offer designers the opportunity to increase the switching frequency with minimal impact on the converter losses, particularly when compared to classical silicon-based devices. This additional degree of freedom in the selection of the switching frequency can be exploited to reduce the losses on the electrical machine and therefore to maximize the efficiency of the overall drive. In this paper, the impact of the PWM switching frequency on the machine losses is investigated and a methodology for the prediction of PWM induced losses is provided. The proposed approach enables the prediction of the PWM-induced losses, starting from the machine impedance, measured with an LCR meter. This allows the selection of the optimal switching frequency minimizing the machine losses. Experimental validation is provided, together with additional consideration on the overall drive efficiency, where both the losses on the converter and the machine are measured for different switching frequencies.