An accurate understanding of modulation-induced motor losses in inverter-fed traction drives is essential for optimizing inverter operation and designing high-efficiency motor drives. However, many studies overlook the impact of parasitic motor effects, leading to incomplete loss models and suboptimal design decisions. This paper addresses that gap by providing both a comprehensive overview and a detailed analysis of the underlying modulation-induced loss mechanisms. Specifically, it characterizes time-harmonic losses in the copper, iron, and magnets under voltage source inverter (VSI) operation. Furthermore, conventional evaluation metrics such as total harmonic distortion (THD) are evaluated for their ability to capture time-harmonic motor losses. A novel impedance-matrix measurement method is used to capture the motor’s wide-frequency response, including quantification of parasitic inter-winding and winding-to-stator capacitances. Loss-equivalent parameter fitting is employed to achieve high modeling fidelity with modest computational cost. Incorporating parasitic effects into the loss model reveals a distinct switching-frequency dependence of system losses. This insight enables identification of an optimal switching frequency that minimizes modulation-induced losses, thereby improving the efficiency and performance of electric drive systems.
