Application of a smart hall effect sensor system for 3-phase BLDC drives

The work done in this paper provides a redundant method to detect the rotor position of a 3-phase BLDC motor. Such motors requires three numbers of hall effect sensor for detecting the rotor position. The information of the rotor position provided by these sensors are then used to obtain the accurate firing timing of the six switches of the 3-phase inverter in the 3-phase BLDC drive system, required for accomplishing the electronic commutation process of the motor. If one of the hall effect sensor stops working due to some damage, then the six firing sequences cannot be obtained and the motor stops running. The proposed work provides the intelligence to the hall sensor system to generate the necessary six firing sequence to run the motor, even when one of the hall sensor suddenly stops working in the middle of the run. This scheme is useful for emergency operation before replacing the damaged hall effect sensor.