Reduction of Speed Ripple in BLDC Motor Aimed at using in the Servomotor of Aircraft Flap

Drivers of brushless direct current motor (BLDC) are widely used for industrial servo applications, including servo motors used in aircraft flaps, where torque smoothness is a key requirement. One disadvantage of torque pulses, however, is the pulsation that causes the speed to fluctuate, which affects the performance of the drive, especially at low speeds and sensitive applications. In this research, to reduce these speed ripples, the iterative learning method (ILC) is presented. Although in brushless direct current motors, a conventional proportional-integral (PI) speed controller suppresses the speed ripples to some extent, the use of this controller alone is not sufficient for many high-performance applications. The simulations showed that utilizing the proposed control to the driver of BLDC motor could well reduce the motor speed ripple.