Patent ID: 7173394

Claim:
An apparatus for controlling an inverter comprising: an inverter for converting an inputted DC voltage into an AC output voltage for driving a motor and providing it; an input voltage detector for detecting the DC input voltage inputted to the inverter; an output voltage ratio computing unit for determining a ratio of an output voltage value to the detected DC input voltage value by calculating a ratio of an output command frequency to a reference frequency; a reference voltage generator for providing a reference voltage value depending on a predetermined motor rated voltage value; a difference voltage computing unit for calculating a difference value between the reference voltage value provided by the reference voltage generator and the DC input voltage value provided by the input voltage detector, and providing it; a compensation voltage computing unit for obtaining a compensation voltage value by multiplying the ratio provided by the output voltage ratio computing unit to the difference voltage value provided by the difference voltage computing unit, obtaining a final compensation voltage value by adding the obtained compensation voltage value to the DC input voltage value provided from the input voltage detector, and providing it; and the inverter for outputting an output voltage of the final compensation voltage value provided from the compensation voltage computing unit to the motor.