A device includes a bidirectional switch circuit 10, a control unit 20 that performs virtual AC/DC conversion processing to acquire a plurality of interline voltage generation sections according to a plurality of modes divided according to a magnitude relation between voltages in each phase and that generates a switching pattern of the bidirectional switch circuit 10 to perform virtual DC/DC conversion processing corresponding to the plurality of interline voltage generation sections based on a second carrier waveform pattern CW2 according to the plurality of modes and a signal level G1 of a P-phase, a current setting unit 50 that inputs a current direction and an amount of current that flows in a power line LU, a current detection unit 51 that detects the current direction and the amount of current of the power line LU, and a current adjustment unit 52 that increases and decreases the signal level G1.