SOLUTION

In a conventional motor the mechanical contactor. the commutator maintains 90° elect degrees space displacement between the rotor and stator magnetic fields to provide for the required torque.

The commutation of the BLDC motor is done electronically. To know the position of the rotor is very important for electrical commutation. Usually, the Hall sensors are placed in 120-degree intervals and the common operation of the BLDC motor is achieved by six-section.

When the magnet poles of the rotor come to the Hall sensor, the signal is generated. According to six-step the commutation sequence is performed. The motor phases are supposed to conduct for 120 electrical degrees two times per cycle. Two phases are only conducted at one time. That is, the six-trigger signals are generated per one cycle. Using these trigger signals, motor control is carried out. With these sensors, three-phase commutations can be achieved so that at any time one of the three-phase coils is positively energized, the second coil is negatively energized, and the third one is not energized.