Power control apparatus

A power control apparatus, comprising:

• a plurality of switch units;
• a cooling unit which supports a plurality of switch units and cools each of the plurality of switch units with a cooling medium which is supplied to flow in an internal space in one direction orthogonal to a direction in which the plurality of switch units are aligned in an aligning direction;
• and an electronic control circuit, wherein
• the electronic control circuit is configured to perform:
• measuring temperatures of each of the plurality of switch units;
• comparing the temperatures of each of the plurality of switch units measured by the measuring step;
• and
• determining whether a temperature difference between any two of the plurality of switch units is greater than or equal to a threshold value based on information from the comparing step, and wherein
• the cooling unit includes:
• a mounting portion on which the plurality of switch units are mounted;
• and
• a main portion, on which the mounting portion is mounted, and which partitions a part of the internal space together with the mounting portion, and wherein
• the main portion includes:
• an opposing portion which opposes the mounting portion in an orthogonal direction which is orthogonal to the aligning direction and the one direction;
• a connecting portion which protrudes from the opposing portion toward the mounting portion in an annular shape and the mounting portion is connected on a distal end thereof;
• and
• a plurality of protruding portions protruding from a portion surrounded with the connecting portion in the opposing portion and aligned in a spaced apart manner in the aligning direction, and wherein
• each of the plurality of switch units is individually cooled by a cooling medium supplied to three passages in the internal space, the passages being formed (i) between one protruding portion located on an end in the aligning direction out of the plurality of protruding portions and the connecting portion located on the one end in the aligning direction, (ii) between two of the protruding portions located on next by next in the aligning direction out of the plurality of protruding portions, and (iii) between one protruding portion located on the other end in the aligning direction out of the plurality of protruding portions and the connecting portion located on the other end in the aligning direction, and wherein the threshold value in the determining step performed by the electronic control circuit is adjusted so that a temperature difference between a temperature of one of the switch units cooled by one of the three passages where corrosion products are deposited and a temperature of another one of the switch units cooled by another one of the three passages where the corrosion products are not deposited is greater than or equal to the threshold value.