Power conversion system and control method for voltage conversion circuit

A power conversion system configured to convert an input alternating-current voltage having a first frequency into an output alternating-current voltage having a second frequency lower than the first frequency, the power conversion system comprising:

• a voltage converter configured to
• convert the input alternating-current voltage into the output alternating-current voltage in accordance with a control signal and
• output the output alternating-current voltage to a load;
• a PDM controller configured to
• perform pulse density modulation of an output voltage command value of the output alternating-current voltage to generate a modulation signal,
• generate the control signal in accordance with the modulation signal, a polarity of the input alternating-current voltage, and a polarity of the output voltage command value, and
• output the control signal to the voltage converter;
• and
• a feedback controller configured to
• generate the output voltage command value based on an output current value of the voltage converter and a state of the load and
• output the output voltage command value to the PDM controller.