There is provided a power electronics device including: a first connection unit, a second connection unit, a power conversion unit and a control unit. The first connection unit and the second connection unit are connected to a first power line and a second power line of plural power lines. The power conversion unit converts power from one of the first and second connection units outputs converted power from the other of the first and second connection units. The control unit selects a master device from power electronics devices connected to a third power line that is one of the power lines including the first power line and the second power line, based on power conversion characteristic information of the power electronics devices. The master device controls other power electronics devices except the master device out of the power electronics devices, regarding output of power to the third power line.