POWER CONTROL SYSTEM

A power converter (2) of self-excited type includes a first arm and a second arm, each of which includes one or more switching elements, and performs power conversion between a DC system (14) and an AC system (80). An AC circuit breaker (12) and a current control circuit (30) are connected in series on a path between the AC system (80) and the power converter (2). The current control circuit (30) includes a current-limiting resistor (31) and a disconnector (32) connected in parallel. A controller (50) instructs a disconnector (32) to close after an initial charge of the power converter (2) and opens the AC circuit breaker (12) when an impedance of a line between a first node located on a first end side of the current control circuit (30) and a second node located on a second end side of the current control circuit (30) is not less than a first threshold and an accumulated value of a current flowing through the current control circuit (30) within a certain period of time is not less than a second threshold.