THREE-PHASE INPUT METHOD TO POWER UNIT, AND POWER UNIT USED THEREFOR AND POWER MODULE

摘要

PROBLEM TO BE SOLVED: To materialize the balancing of a phase current in a three-phase AC power source at low cost in the case of operating a plurality of power units in parallel by the three-phase AC power source. SOLUTION: Each power unit has a balance current input-output part (b) which inputs and outputs a balance current for taking the balance of an output current of each power unit with each other's AC input terminals not connected and with each other's DC output terminals connected in parallel; and a current balancer 11 which receives the input of the balance current inputted from the balance current input-output part and a detection current corresponding to its own output current and performs the output action for balancing its own output current with the above balance current from the above balance current and the above detection current. The balancer 11 balances each-phase current of the three-phase AC power source by the balancing action of the output current of each power unit by the current balancing part, when the interline voltage from the three-phase AC power source 3 is applied between the AC input terminals of each power unit in order of phases.