A plasma arc cutting system includes a power supply comprising a multi-pulse transformer and a plurality of semiconductor switches directly connected to a bank of capacitors, and a thermal regulation system connected to the power supply and configured to cool the multi-pulse transformer. The thermal regulation system includes a cold plate in direct contact with the semiconductor switches; a fluid conduit disposed within the cold plate; and a pump connected to the conduit and configured to direct a coolant fluid through the conduit. The power supply has at least one of the following operating requirements: (i) a weight to power ratio of approximately 22.4 pounds per kilowatt; (ii) a volume to power ratio of approximately 1366 cubic inches per kilowatt; (iii) an average semiconductor device case temperature of approximately 100 degrees Centigrade during a cutting operation; (iv) a maximum transformer temperature of about 133 degrees Centigrade during a cutting operation.