Method for operating a BLDC motors

摘要

A BLDC motor is operated by driving the motor with a first PWM driving signal during a start up phase of operation. Subsequent to the start up phase, the method switches to driving the motor with a second PWM driving signal for ongoing operation. In such manner, the operation of the motor can be controlled according to an optimised cycle for the initial conditions and a separate optimised cycle for ongoing operation. For instance, by driving the motor at increased PWM duty cycle in a start up phase the acceleration of the motor can be increased and thus the motor can achieve a desired rotation speed after a shorter time interval. Subsequently driving the motor with a lower PWM duty cycle allows the motor speed to be maintained at a desired nominal level whilst reducing the power consumption of the motor. Alternatively, initiating motor driving using a PWM driving signal at a first low duty cycle value in a start up phase; and increasing the driving signal duty cycle value progressively until a higher target PWM duty cycle value for ongoing operation is reached can enable a 'soft' start to be achieved thus reducing the potential for overload or for damage.