Power Conversion System

A power conversion system that performs power conversion between a first AC power system and a second AC power system, the power conversion system comprising:

• a positive-side DC bus and a negative-side DC bus;
• a plurality of first upper arms connected between respective phases of the first AC power system and the positive-side DC bus;
• a plurality of first lower arms connected between the respective phases of the first AC power system and the negative-side DC bus;
• a plurality of second upper arms connected between respective phases of the second AC power system and the positive-side DC bus;
• and
• a plurality of second lower arms connected between the respective phases of the second AC power system and the negative-side DC bus, wherein
• each of the plurality of first upper arms, the plurality of first lower arms, the plurality of second upper arms, and the plurality of second lower arms includes:
• a plurality of submodules cascade-connected to each other, each of the plurality of submodules serving as a unit converter that converts between AC power and DC power;
• and
• a reactor connected in series to the plurality of submodules,
• in each of the plurality of first upper arms and each of the plurality of second upper arms, the plurality of submodules are connected between the reactor and the positive-side DC bus,
• in each of the plurality of first lower arms and each of the plurality of second lower arms, the plurality of submodules are connected between the reactor and the negative-side DC bus,
• the power conversion system further comprises at least one housing chamber that houses the plurality of submodules of each of the plurality of first upper arms, the plurality of submodules of each of the plurality of first lower arms, the plurality of submodules of each of the plurality of second upper arms, the plurality of submodules of each of the plurality of second lower arms, the positive-side DC bus, and the negative-side DC bus,
• the reactor of each of the plurality of first upper arms, the reactor of each of the plurality of first lower arms, the reactor of each of the plurality of second upper arms, and the reactor of each of the plurality of second lower arms are provided outside the at least one housing chamber,
• each of the positive-side DC bus and the negative-side DC bus is arranged to extend in substantially one direction in a plan view,
• the plurality of submodules of each of the plurality of first upper arms and the plurality of submodules of each of the plurality of second upper arms are arranged opposite to each other with respect to the positive-side DC bus in a plan view, and
• the plurality of submodules of each of the plurality of first lower arms and the plurality of submodules of each of the plurality of second lower arms are arranged opposite to each other with respect to the negative-side DC bus in a plan view.