A controller and method for operating a plurality of capacitors of a first phase, wherein the first phase is one of a plurality of phases applied to the motor, a plurality of first switching elements of the first phase, and a plurality of second switching elements of the first phase. The plurality of capacitors charge DC voltage from a battery that applies voltage to the motor. The plurality of first switching elements convert the DC voltage to AC voltage. The plurality of second switching elements switch so that any one of the plurality of capacitors or the plurality of first switching elements is selectively connected to the motor.