Patent ID: 7816899

Claim:
A power conversion device, comprising: a power converter circuit having a coil, and a high side switch and a low side switch which change over a path of a current that flows in the coil; switching ratio setting means for setting a switching ratio of the power converter circuit so that an output from the power converter circuit is controlled to a target value; and PWM signal generating means for generating PWM signals that allow the high side switch and the low side switch to alternately turn on and off, respectively, based on the switching ratio that is set by the switching ratio setting means, the PWM signals being provided with a dead time for turning off both of the high side switch and the low side switch when the respective switches are changed over; coil current detecting means for detecting a coil current that flows in the coil of the power converter circuit; current direction determining means for determining a direction of the coil current during a dead time period where the high side switch and the low side switch are off based on a detection signal from the coil current detecting means; and PWM signal correcting means for correcting the PWM signals of the respective switches which are generated by the PWM signal generating means according to a determination result of the current direction determining means to change the coil current according to the switching ratio.