Patent ID: 9543885
Date: 2017-01-10
CPC Classifications: B60L,H02P,Y02T

Claim:
1. A rotary electric machine driving device that drives and controls an alternating-current rotary electric machine, the rotary electric machine driving device comprising: an inverter that is electrically interposed between a direct-current power supply and the rotary electric machine, and converts electric power between a direct current and an alternating current; a smoothing capacitor that is electrically interposed between the direct-current power supply and the inverter, and is connected between a positive pole and a negative pole on a direct-current side of the inverter; and an inverter control unit that controls switching of a switching element of the inverter according to a predefined switching frequency, wherein the inverter control unit sets the switching frequency to a value varying corresponding to both torque and a rotating speed of the rotary electric machine, according to pulsation amplitude of a system voltage that is a voltage on the direct-current side of the inverter and pulsation amplitude of a power supply current that is a current flowing through the direct-current power supply, and the inverter control unit sets the switching frequency higher as rotary electric machine power or a modulation factor increases, the rotary electric machine power being calculated by multiplying the torque by the rotating speed of the rotary electric machine, the modulation factor representing a ratio of an effective value of an alternating-current voltage command value to a system voltage that is a voltage on the direct-current side of the inverter.