Patent ID: 8063596

Claim:
An apparatus for driving a switching member of a power converter so as to generate, from an inputted DC (Direct Current) voltage, a variable output voltage of the power converter, the output voltage being applied to a rotary machine and adjusting a controlled variable of the rotary machine, the apparatus comprising: a first drive unit configured to drive, in a first range of a voltage utilization factor, the switching member of the power converter to thereby control the output voltage of the power converter to be matched with a command voltage, the voltage utilization factor being defined based on a ratio of the output voltage to the inputted DC voltage; a second drive unit configured to drive, in a second range of the voltage utilization factor, the switching member to thereby generate a value of the controlled variable of the rotary machine, the second range of the voltage utilization factor being higher than the first range thereof; and an estimating unit configured to estimate, during the switching member being driven by the second drive unit, a value of a parameter associated with the output voltage of the power converter, the estimated value of the parameter being required for the first drive unit to generate the value of the controlled variable generated by the second drive unit.