| abstract |
An electromagnetic noise is prevented from increasing. When the absolute value of the motor speed change rate ΔNm is equal to or less than a threshold value ΔNmref and the absolute value of the absolute value of the motor torque command change rate ΔTm * is equal to or less than a threshold value ΔTmref (S202, S204), periodically, The switching angle is changed by changing the pulse type and the number of pulses as the change of the pulse pattern PP (S300). Thereby, each order component of a harmonic can be disperse | distributed, and the grade which the component of the specific order in a harmonic protrudes with respect to the component of another order can be made small. [Selection] Figure 4 |