Patent ID: 8493010
Filing Date: 2013-07-23
Classification: H02P

Abstract:
1. A method comprising: measuring first and second currents respectively associated with a first and a second phase of a motor; calculating a third current associated with a third phase of the motor using the first and the second currents; calculating a first delivered power associated with a first duty cycle of the motor, based off of the third current; determining an error signal, which is a difference between the first delivered power associated with the first duty cycle and a first commanded power associated with the first duty cycle; compensating for the error signal; calculating duty cycle drive signals for each of the phases; and applying the duty cycle driver signals to the motor, wherein applying the duty cycle driver signal compensates for winding torque distortions in the motor, wherein the step of compensating for the winding torque further comprises maintaining a substantially constant power for the motor; wherein maintaining a substantially constant delivered power for a constant rotational speed generates a substantially constant torque, wherein a constant torque produces less acoustic noise because a torque ripple is substantially constant, and wherein the motor is associated with a hard disk drive (HDD).