Power Conversion System and Control Device for Same

In a power conversion system, a first power converter is connected between a first AC power system, and a first DC main line and a DC return line. A second power converter is connected between the first AC power system, and the DC return line and a second DC main line. A first control device controls the first power converter in accordance with a first active power command value. A second control device controls the second power converter in accordance with a second active power command value. A common control device sets the first active power command value and the second active power command value by distributing a command value of total active power output from the entire power conversion system to the first AC power system. The common control device makes the first active power command value and the second active power command value different from each other.