Inverter device and control method thereof

An inverter device comprising a power portion performing PWM control on a voltage command to a motor for each set time period and outputting alternating-current power, comprising:

• a voltage command generation portion generating a voltage command in synchronization with a period N-times longer than the time period, where N≧1;
• an interval determination portion generating an interval determination signal which is ON during a half period of the time period and OFF during a next half period;
• a current detection portion detecting a current of the motor at timing of change in the interval determination signal;
• a voltage correction value storage portion storing a voltage correction table employing at least an electrical angle phase of a current or a magnitude of the current as an argument;
• a voltage correction value retrieving portion retrieving a voltage correction value from the voltage correction table;
• and
• a voltage correction portion correcting the voltage command with the voltage correction value.

A control method of an inverter device comprising a power portion performing PWM control on a voltage command to a motor for each set time period and outputting alternating-current power, comprising:

• generating an interval determination signal which is ON during a half period of the time period and OFF during a next half period;
• detecting a current of the motor at timing of change in the interval determination signal;
• calculating a difference value between a current detection value and its previous value;
• generating a voltage correction value such that the amount of change in the current of the motor when the interval determination signal is ON becomes equal to the amount of change in the current of the motor when the interval determination signal is OFF;
• and
• correcting the voltage command with the voltage correction value.

A control method of an inverter device comprising a power portion performing PWM control on a voltage command to a motor for each set time period and outputting alternating-current power and a voltage correction value storage portion storing a voltage correction table, comprising:

• generating a voltage command in synchronization with a period N-times longer than the time period, where N≧1;
• generating an interval determination signal which is ON during a half period of the time period and OFF during a next half period;
• detecting a current of the motor at timing of change in the interval determination signal;
• calculating a given current command or at least either an electrical angle phase of the detected current or a magnitude of the detected current;
• retrieving a voltage correction value, employing at least the electrical angle phase of the current or the magnitude of the current as an argument;
• and
• correcting the voltage command with the voltage correction value.