A Practical Inductor Loss Testing Scheme and Device with High Frequency PWM Excitations

Voltages across magnetic components of power converters are generally pulsewidth modulation (PWM) waveforms, whereas the parameters of present magnetic core loss models are often tested under sinusoidal excitation by most magnetic material manufacturers. This leads to a significant difference with a PWM excitation and then impacts the testing accuracy of inductor losses. A testing device, based on dc law, has been designed to generate different kinds of PWM waveforms, and a corresponding testing scheme is proposed to accurately measure total inductor losses of different inductances with high frequency PWM excitations. Finally, experiments have been conducted to verify the effectiveness and correctness of the proposed scheme. The results show that the proposed testing scheme can accurately test the total inductor loss. Moreover, the proposed loss model of the testing device is in exact agreement with the actual device's loss with the fitting error within 1%, ensuring the accuracy of the proposed testing scheme.