Patent ID: 7538514

Claim:
A method for controlling torque of a motor, the motor having first, second, and third phase coils, the method comprising: determining a motor position value indicative of a position of the motor; determining a first phase advance angle associated with the first phase coil; determining when a shorted operational condition occurs at an input node of the first phase coil; when both the short operational condition is occurring and the motor position value indicates the motor is within a predetermined angular range, then determining a second phase advance angle associated with the first phase coil based on a calibration value; determining first, second, and third phase voltage amplitude values based on the second phase advance angle; determining first, second, and third duty cycle values based on the first, second, and third phase voltage amplitude values, respectively; and determining a modified first duty cycle value based on the first duty cycle value and a first predetermined value, the modified first duty cycle value indicative of a voltage that would be present at the input node of the first phase coil during the shorted operational condition; determining a modified second duty cycle value based on the second duty cycle value and a second predetermined value; and determining a modified third duty cycle value based on the third duty cycle value and a third predetermined value; and applying first, second, and third voltages having first, second, and third duty cycles, respectively, based on the modified first, second, and third duty cycle values, respectively, to the first, second, and third phase coils, respectively, to obtain a desired torque from the motor.