Influence Rate of Semiconductor ON-Voltage in Inverter Circuit on Iron Loss Inside a Non-Oriented Electrical Steel Sheet

We calculate an iron loss attributed to semiconductors ON-voltages in an inverter circuit and reveal influence rate of the ON-voltages on whole iron loss. In our previous work, it has been revealed by inverter excitation that the ON-voltages make minor loops in magnetic hysteresis of magnetic material and the loops affect iron loss characteristics. In this paper, it is investigated by a factor analysis how much the on-voltage has an influence on iron loss, quantitatively. We separate whole iron loss caused in a non-oriented electrical steel sheet into three losses: loss by the ON-voltage, loss by fundamental component, and loss by inverter carrier. The rates of these losses are evaluated under several conditions of single-phase pulse width modulation inverter excitation, and the results show that the proportion of loss by ON-voltages is up to around 10% depending on inverter excitation parameter: fundamental frequency, carrier frequency, modulation index, and magnetic flux density.