Patent 10093199 was granted and assigned to Toyota on October, 2018 by the United States Patent and Trademark Office.
When an absolute value of a rotation speed change rate of a motor is equal to or less than a threshold and an absolute value of a torque command change rate of the motor is equal to or less than a threshold, a switching angle is changed by cyclically changing a pulse type or the number of pulses as change in a pulse pattern. With this, respective order components of harmonics are dispersed, whereby it is possible to reduce the degree of prominence of a specific order component in harmonics relative to other order components.