Power conversion system

A power conversion system that transmits AC power generated by a power generator through a DC power grid to an AC power grid, the power conversion system comprising:

• an AC/DC power converter to convert the AC power from the power generator into electric power of a first DC voltage, and output the electric power of the first DC voltage;
• a DC/DC power converter to convert the electric power output from the AC/DC power converter into electric power of a second DC voltage, and output the electric power of the second DC voltage to the DC power grid;
• and
• a control device to control the AC/DC power converter and the DC/DC power converter, wherein
• the control device includes
• a first drive controller to control the AC/DC power converter such that an active current component and a reactive current component of an AC current output from the power generator follow an active current command value and a reactive current command value, respectively, and
• a second drive controller to control the DC/DC power converter such that the first DC voltage follows a DC voltage command value, and
• when a fault occurs in the DC power grid or the AC power grid, the control device decreases at least one of the active current command value and the DC voltage command value in accordance with fluctuations of the second DC voltage, to suppress electric power that flows from the power generator into the AC/DC power converter.