Magnet Brushless Motor Research Paper

Permanent magnet synchronous motor is special type of brushless motor. In PMSM motor does not require the mechanical commutatation or brushes. The mechanical commutator is replaced by electronic commutation. The absence of brushes and slip ring offers low maintainance, high torque to weight ratio, higher efficiency, lower inertia and better dynamic performance. The PMSM motor operates at higher power factor than induction motor. These advantages makes permanent magnet synchronous motor (PMSM) more suitable in various applications such as electric road vehicles, people movers,air conditioners, industrial drives, pumps, blowers, mills and so on, because of the high efficiency and the reduced size.
A typical conventional motor consists of a stator with a fixed electromagnet and a rotor

Depending on how the stator is wounded, the back-electromagnetic force will have a different shape (the Back EMF is induced in the stator by the motion of the rotor). To obtain the maximum performance from each type of Permanent Magnet Synchronous Motor, an appropriate control strategy has to be implemented. The trapezoidal Back EMF motor called DC brushless motor (BLDC) uses a "two phases on" strategy, whereas the sinusoidal Back EMF motor offers its best performances when driven by sinusoidal currents (three phases on strategy).
The rotor of a permanent magnet brushless dc motor (BLDC) is similar to that of a permanent magnet synchronous motor (PMSM). But, its stator is made of concentrated windings. The distribution of the stator windings of a permanent magnet synchronous motor (PMSM) is sinusoidal. Eventually, with the advent of electronic drives, it became possible to place the magnets of the motor on the rotor, and the windings on the stationary stator. The switching of stator current into the right phase depending on the rotor