Patent ID: 9705444
Date: 2017-07-11
CPC Classifications: H02P

Claim:
1. A device for controlling an electric motor, the device comprising: an inverter supplying a current; a current sensor sensing current supplied from the inverter; and a control unit enabling the current to be supplied from the inverter to the electric motor, obtaining first and second offset values sensed by the current sensor at a plurality of times, comparing the first and second offset values, and updating the first offset value to the second offset value according to a result of the comparison, wherein the control unit obtains the first offset value, determines whether the first offset value is within a range of reference offset values and controls the electric motor based on the first offset value when the first offset value is within the range of reference offset values, wherein the control unit obtains the second offset value, determines whether the second offset value is within the range of reference offset values, compares the first offset value with the second offset value when the second offset value is within the range of reference offset values, updates the first offset value to the second offset value when a difference between the first offset value and the second offset value is less than a reference value of effectiveness and controls the electric motor based on the first offset value when the first offset value is within the range of reference offset values, and wherein the first and second offset values are obtained in a state of non-performance of current control of the electric motor during operation of the electric motor.