Inverter control device

An inverter control device comprising:

• an inverter main circuit converting a direct-current voltage into three-phase alternating-current voltages;
• a direct current detection unit detecting a direct current value of an electric direct current flowing in the inverter main circuit;
• and
• a control unit generating a drive signal for controlling an operation of the inverter main circuit using a voltage command value corresponding to each phase of the three-phase alternating-current voltages and a triangular wave carrier signal, wherein
• using a time period during which the triangular wave carrier signal monotonically increases or monotonically decreases as a unit period, the control unit provides control to alternately use, as the direct current value to be used in computation of the voltage command value, the direct current value detected in a unit period in which the triangular wave carrier signal monotonically increases and the direct current value detected in a unit period in which the triangular wave carrier signal monotonically decreases, for every voltage command value control period that is a period for computing the voltage command value, the voltage command value control period being set to three times or more of and an integer multiple of the unit period,
• in a case in which the voltage command value control period corresponds to an odd number times of the unit period, the control unit repeats a process of:
• reflecting a voltage command value obtained through computation to set a new voltage command value from in one unit period before a start of a next voltage command value control period;
• and computing a next voltage command value using a direct current value detected in one unit period from one unit period before the start of the next voltage command value control period, and
• in a case in which the voltage command value control period is an even number times of the unit period, the control unit alternately performs, for every voltage command value control period, a process of:
• reflecting a voltage command value obtained through computation to set a new voltage command value from in two unit periods before the start of the next voltage command value control period;
• and computing a next voltage command value using a direct current value detected in one unit period from two unit periods before the start of the next voltage command value control period, and another process of:
• reflecting the voltage command value obtained through computation to set a new voltage command value from in two unit periods before the start of the next voltage command value control period;
• and computing a next voltage command value using a direct current value detected in one unit period from one unit period before the start of the next voltage command value control period.