Patent ID: 11909341
Assignee: HITACHI INDUSTRIAL EQUIPMENT SYSTEMS CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 6:
7. A control method of a power conversion device that controls driving of a motor by converting a DC voltage into a voltage based on a voltage command by an operation of a switching circuit, the method comprising:
generating a square wave based on the voltage command, as a first modulated wave, from the voltage command;
generating a control signal for controlling the operation of the switching circuit from the first modulated wave and a carrier wave:
detecting the DC voltage;
calculating a voltage utilization rate from the voltage command and the DC voltage;
injecting a zero-phase voltage into the voltage command to generate a second modulated wave;
selecting the first modulated wave and the second modulated wave based on the voltage utilization rate; and
generating a control signal for controlling the operation of the switching circuit from either the selected first modulated wave or the selected second modulated wave and a carrier wave.