Patent attributes
Each of the plurality of generators is configured so a relationship of frequency with respect to a generator active power output by each generator to the corresponding alternating-current wiring unit has a predetermined first drooping characteristic. The plurality of power conversion devices is configured to convert alternating-current power input through each alternating-current wiring unit into direct-current power, and to convert direct-current power input through the direct-current wiring unit into alternating-current power. The control device is configured to determine a target value of a control element such that a relationship of frequency with respect to a power conversion device active power output by each power conversion device to the corresponding alternating-current wiring unit has a predetermined second drooping characteristic, and is configured to generate a drive signal for each power conversion device by correcting a target value of the control element in response to direct-current voltage at the direct-current wiring unit.