Evaluation of Iron Loss of AC Filter Inductor Used in Three-Phase PWM Inverters Based on an Iron Loss Analyzer

The authors have proposed two methods for iron loss evaluation of the ac filter inductor used in a pulsewidth modulation (PWM) inverter. The first method is a loss map method, which can be used for the iron loss calculation of the ac filter inductor without using a real PWM inverter, and the second method is an iron loss analyzer (ILA), which can measure the iron loss of the ac filter inductor during every switching period on a real PWM inverter. In this paper, the measurement results obtained using the ILA and the results calculated using the loss map method on both the single-phase and three-phase inverters are compared. The calculated iron loss of the ac filter inductor on the three-phase PWM inverter is found to have a relatively large error for certain PWM pulse conditions. In order to reduce the calculation error, the authors propose a modified loss calculation method and demonstrate that the calculation error is reduced to less than 2%.