Patent ID: 7426122

Claim:
An apparatus for controlling a power converter in which an output voltage is controlled by pulse-width-modulation control, the apparatus comprising: a voltage-vector control unit that determines, based on a voltage instruction value for the power converter, voltage vectors, including zero-voltage vectors, output from the power converter in a control cycle of the pulse-width-modulation control and durations of outputting of the voltage vectors; a voltage-vector adjusting unit that adjusts the durations of outputting of the voltage vectors so that, if total of the durations of outputting of the zero-voltage vectors in the control cycle is longer than a predetermined time that is longer than zero, the voltage-vector adjusting unit adjusts durations of outputting of the zero voltage vectors to a fixed time or longer, and, if the total is shorter than the predetermined time, the voltage vector adjusting unit adjusts the durations of outputting of the zero voltage vectors to zero; and a firing-pulse generating unit that generates a signal for turning on and off semiconductor switching elements included in the power converter, based on the durations of outputting of the voltage vectors, as adjusted by the voltage-vector adjusting unit.