POWER CONVERSION APPARATUS

PROBLEM TO BE SOLVED: To provide a power conversion apparatus eliminating insulation between a power converter board and a pure water cooler board and capable of lumping together ground lines in a panel row structure.SOLUTION: A power conversion apparatus includes: a power converter board 1 in which semiconductor elements are cooled by pure water flowing in a water pipe in the board, and arranged so as to be insulated from an installation place 3; a pure water cooler board 2 arranged with the power converter board 1 in a panel row structure, having a heat exchanger 6 installed so as to be insulated from a frame, and arranged so as to be insulated from the installation place; an inner water pipe 8 connected to an inner water pipe 10 of the power converter board 1, and arranged in the pure water cooler board 2 so as to circulate the pure water in the heat exchanger 6; and an outer water pipe 5 installed so as to be insulated from the frame of the pure water cooler board 2, for returning from the outside outer water to be heat-exchanged with the pure water in the heat exchanger 6. In the apparatus, insulating parts 7 are provided for insulating the inner water pipe 10 in the power converter board 1 from the heat exchanger 6, and one point of the frame of the power converter board 1 or the pure water cooler board 2 is grounded to the installation place 3.