Conference: 2021 International Conference on Magnetics (INTERMAG)
Authors: Xu Gu, Jun-Yeol Ryu, Jun-Woo Chin, Myung-Seop Lim
DOI:
Iron loss in the core is an important factor in the design of motors. Because harmonic current can be generated when the motor is driven by an inverter with pulse width modulation (PWM), the predicted results ignoring the current harmonics by the PWM often causes errors from experiments. However, a nonlinear finite element analysis (FEA) with the PWM current requires much analysis step. So, a combined nonlinear and linear FEA is proposed to accelerate the computational time and to compare the conventional nonlinear iron loss analysis methods based on the fundamental current and PWM current. First, nonlinear FEA is performed using the fundamental current of PWM current, and the minimum analysis steps are determined. Second, by extracting and interpolating the permeability in the former step, the linear FEA is performed using the PWM current. Then, the iron loss is then calculated. To verify the proposed method, an E-I core wound with litz wire is used to separate the iron loss. Finally, the iron loss of a traction motor for an electric vehicle is calculated using the proposed method, which exhibits a high accuracy and short computational time.