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

Pulse width modulation (PWM) is commonly utilized in voltage-source inverters for driving motors, but it leads to various harmonics components in the voltage and current of the motor, resulting in the loss increment. This paper reveals the mechanism of iron loss increment in motors caused by PWM harmonics based on the hysteresis phenomenon of soft magnetic materials. The voltage and current harmonics induced by the SVPWM supply are analyzed in detail and verified through simulation and experiments. An iron loss calculation method based on a dynamic hysteresis model is proposed. The effect of the excitation harmonics on the magnetic field and hysteresis property is analyzed by combining finite element analysis with the hysteresis-based iron loss calculation method. Taking a 5.5 kW, 3000 rpm PMSM as an example, the hysteresis distortion and iron loss increment mechanism caused by the magnetic field harmonics are discussed in detail. The effects of SVPWM parameters on motor current, magnetic field, hysteresis characteristics, and iron loss are investigated and verified by experiments. The conclusions of this paper can provide a reliable guide for the performance optimization of motors and their control systems.