Control Method that Reduces the High Harmonic in the Overmodulation Drive of the Dual Winding Motor during Voltage Supply Unbalance

Abstract

More reliable motor drive systems are expected in the realization of automated driving. The redundant motor drive system with two voltage supplies, two inverters, and a dual winding motor is one of the strong candidates since the two systems that construct the motor drive system are electrically independent. The dual winding motor has a characteristic of cancelling the 6 th harmonic produced in the overmodulation drive. However, it loses its characteristic when there is a voltage difference in the two voltage supplies. In this paper, it is proposed to control only the sum of the current during the overmodulation to maintain the characteristic of cancellation even if there is voltage difference in the two voltage supplies. Furthermore, the current difference of the two windings is controlled in the sinusoidal wave region to suppress the deviation of currents and turned off during the overmodulation to reduce 6 th harmonic. The maintained characteristic during voltage supply unbalance is confirmed with the experiment.

Novel Two-Phase PWM Scheme by Using Variable Switching Pause Period for Unbalanced Three-Phase Inverter

“…Among them, the effect of the variability of three-phase inverters is one of the causes that hinders their longevity, and various solutions to the unbalanced threephase inverters have been proposed e.g. (1) .…”