Effect of Inverter Parameters on Iron Losses in a PWM Inverter-Fed Induction Motor

The paper investigates the iron losses in a PWM inverter-fed induction motor. The frequencies of PWM voltages are supplied from 60 to 400 Hz. The measurement of core losses of electrical steel laminations in Epstein Frame is implemented to obtain the curves of core loss versus magnetic flux density under sinusoidal waveform step by step from 60 Hz to 5000 Hz. The core losses in the two different material laminations under 60~400Hz sinusoidal PWM voltage are measured and compared. The magnitude and distribution of core losses in the induction motor are evaluated by using a 2D finite element modeling. The study for the induction motor is compared and analyzed by two different materials. The 1 k-20 k Hz switching frequencies of a PWM inverter are varied to evaluate their effect on core losses in motor laminations. Furthermore, the influences of different PWM modulation indices on core losses in the induction motor laminations are also investigated in the paper.