Power conversion device and method for controlling same

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 device comprising:

• a modulated wave generator that generates a first modulated wave from the voltage command;
• a control signal generator that generates a control signal for controlling the operation of the switching circuit from the first modulated wave and a carrier wave;
• a DC voltage detector that detects the DC voltage;
• a voltage utilization rate calculator that calculates a voltage utilization rate from the voltage command norm and the DC voltage;
• and
• a zero-phase voltage injector that injects a zero-phase voltage into the voltage command to generate a second modulated wave,
• wherein the control signal generator controls switching between the first modulated wave and the second modulated wave based on the voltage utilization rate calculated by the voltage utilization rate calculator, and
• wherein the modulated wave generator generates a square wave based on a voltage command norm as the first modulated wave.