A power inverter having: three or more PWM-type power inverting units which are so arranged and constructed as to be enabled to be driven in parallel; a plurality of integrated interphase reactors, each of which is so arranged and constructed as to synthesize each of the same phase output currents of the respective PWM-type inverting units and supply the synthesized phase output current to a load such as a three-phase induction motor; a plurality of current balance controllers, each of which is so arranged and constructed as to carry out a retardation correction for a PMW waveform outputted from the respective PWM-type power inverting units in the corresponding phase so that each phase current between the respective PWM-type inverting units is balanced.