Power-optimal brushless DC motor control involves measuring time difference between null crossings of induced voltage in non-current-carrying coil, commutating next phase after half time difference

摘要

The method involves continuously updating commutation time points by measuring the time difference between two immediately successive null crossings (TN1,TN2) of the induced voltage in the non-current-carrying motor coil and commutating the next motor phase after half the determine time difference has elapsed. This is continued, using a switching algorithm for all phases. Independent claims are also included for the following: (a) a circuit arrangement for power-optimal control of brushless DC motors (b) a method of starting a BDLC motor (c) and a method of fault-tolerant power-optimal operation of a BDLC motor.