Measurement and Modeling of Wide-Range Magnetic Core Losses under PWM Excitation

Error in the direct current power method for measuring magnetic core losses mainly depends on the accurate measurement of device losses in the DC/AC inverter circuit. The existing calibration models for measurement devices fail to reflect the effects of switch states and duty cycles, thus reducing the accuracy of the model. In this study, the operational states of the inverter circuit with different duty cycles and switch states were analyzed, and theoretical analysis was conducted on the losses of each part. Consequently, a symmetric/asymmetric PWM excitation-based calibration model for DC/AC inverter losses, considering the effects of switch transitions and duty cycles, was proposed. Experimental validation showed that the predicted losses using this model were more accurate compared to existing two-parameter and eight-parameter models.