Patent ID: 11888422
Assignee: NIPPON STEEL CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 3:
4. A motor driving system comprising:
an inverter;
a motor which is driven with reception of supply of AC power from the inverter; and
a controller which controls an operation of the inverter,
wherein the inverter has a switching element configured using a wide band gap semiconductor,
wherein the controller has a carrier frequency setting unit which sets a carrier frequency of the inverter based on a relationship between a torque of the motor and the carrier frequency in the inverter derived for each rotation speed of the motor,
wherein the relationship between the torque of the motor and the carrier frequency derived for each rotation speed of the motor has a portion in which the carrier frequency increases as the torque of the motor increases, and
wherein the relationship between the torque of the motor and the carrier frequency derived for each rotation speed of the motor has a portion in which the carrier frequency decreases as the torque of the motor increases in a range in which the torque of the motor is equal to or less than the torque of the motor corresponding to a lowest carrier frequency of the portion in which the carrier frequency increases as the torque of the motor increases.