Hysteresis-Based Mechanism Analysis of Iron Loss Increment Caused by PWM Harmonics in Permanent Magnet Synchronous Motor

The pulse width modulation (PWM) technique is commonly utilized in voltage-source inverters for driving motors, but its application introduces a large number of harmonics into the voltage and current of the motor, resulting in an increment in iron loss. This paper reveals the underlying mechanism of iron loss increment caused by PWM harmonics based on the hysteresis behavior of soft magnetic materials. An iron loss calculation method that integrates an advanced hysteresis model with strategy-circuit-field simulation is proposed. This approach accounts for the interaction of motors and the inverters to obtain the distortion and distribution of current harmonics caused by PWM. The visual correlation between harmonic components and iron loss is established directly through the hysteresis performance of materials. The mechanism of the increment in iron loss due to PWM harmonics is explored and revealed thoroughly from point to line to the surface of the motor core. Additionally, the influence of PWM parameters on iron loss is comprehensively analyzed, providing a criterion for the optimization of motor performance. The accuracy and reliability of the proposed method are verified by experiments under various conditions.