POWER CONVERSION DEVICE

摘要

The purpose of the invention is to obtain a power conversion device used in a DC power transmission system in which a plurality of power supply systems are connected therebetween by a DC line and interconnected with each other and being capable of preventing accidental current from flowing while suppressing an electricity transmission loss during a normal time, without causing the size of the equipment to increase and without causing the cost to increase. The power conversion device comprises: a converter (2) for performing power conversion between power supply systems (20-1, 20-2) and a DC power transmission system; and a current-limiting circuit (5) provided between the converter (2) and a DC line (1) and consisting of a current-limiting element (4) and an opening and closing device (3) connected in parallel with the current-limiting element (4). When the current flowing through the converter (2) exceeds a threshold value that is lower than the upper limit value of allowable current of the converter (2), the opening and closing device (3) is controlled to open.