Patent attributes
A power conversion apparatus includes serially connected arms U and X, serially connected arms V and Y, serially connected arms W and Z, and a capacitor, the pairs of serially connected arms and the capacitor all connected in parallel to one another. The input-side arms U and X and the output-side arms W and Z are subjected to PWM control so that the arms W and Z are controlled to have a voltage that is lower than that of the arms U and X, thereby providing a step down operation. A step up operation also can be provided by an opposite relation in which the arms W and Z are controlled to have a voltage that is higher than that of the arms U and X, thereby to expand the range within which the output voltage is controlled with the effect of reducing distortion.
