Inverter device

An inverter device comprising:

• an inverter circuit having an upper arm switching element and a lower arm switching element connected in series for each phase between an upper arm power supply line and a lower arm power supply line, and applying a phase voltage at a connection point of the upper and lower arm switching elements of each phase to a motor as a three-phase AC output;
• and
• a control device which controls switching of the upper and lower arm switching elements of each phase of the inverter circuit,
• wherein the control device includes:
• a phase voltage command operation unit which calculates and outputs a continuous modulation voltage command value for generating a voltage applied to each phase of the motor,
• an inter-line modulation operation unit which calculates based on the continuous modulation voltage command value, a discontinuous modulation voltage command value which fixes an ON/OFF state of the upper and lower arm switching elements of one phase of the inverter circuit, and modulates an ON/OFF state of the upper and lower arm switching elements of the other two phases, and
• a PWM signal generation unit which generates a PWM signal PWM-controlling the inverter circuit, based on the discontinuous modulation voltage command value, and
• wherein the control device synchronizes switching timings of the upper and lower arm switching elements of the two phases in which the ON/OFF state is modulated, and cancels a change in the phase voltage applied to the motor by a change in the other phase voltage.