CPC H02M 1/123 (2021.05) [H02M 7/483 (2013.01); H02M 7/5395 (2013.01); H02M 7/53875 (2013.01); H02M 7/4835 (2021.05)] | 8 Claims |
1. A power conversion device that converts direct current power into alternating current power for a load, and supplies the alternating current power to the load, the power conversion device comprising:
a three-phase three-level inverter connected between positive and negative terminals of a direct current power supply;
three single-phase inverters respectively connected between the load and alternating current terminals of respective phases different from one another, of the three-phase three-level inverter; and
a controller to generate gate signals for controlling operation of the three-phase three-level inverter and of the three single-phase inverters, based on sinusoidal phase voltage commands, wherein
the controller
divides the sinusoidal phase voltage commands into three-phase instantaneous voltage commands to be indicated to the three-phase three-level inverter and mean voltage commands to be indicated to the respective three single-phase inverters, and
in a case in which a sum of the three-phase instantaneous voltage commands is a positive value, superimposes a common voltage component on each of the three mean voltage commands to make a sum of the three mean voltage commands a non-positive value, or
in a case in which the sum of the three-phase instantaneous voltage commands is a negative value, superimposes the common voltage component on each of the three mean voltage commands to make the sum of the three mean voltage commands a non-negative value.
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