POWER CONVERSION DEVICE, CONTROL DEVICE, AND DISTRIBUTED POWER SOURCE SYSTEM

A power conversion device includes a major circuit part converting a power of a distributed power source into AC power corresponding to a power system, and a controller controlling an operation of the major circuit part; the controller includes an estimated value calculation part and a reactive power calculation part; the estimated value calculation part calculates an estimated value of a resistance component of a system impedance of the power system, an estimated value of a reactance component of the system impedance, and an estimated value of a voltage value of the infinite bus power system based on an active power value of a connection point to the power system, a reactive power value of the connection point, and a voltage value of the connection point.