II. MOTOR AND CONTROL
A. BLDC Motors
Brushless dc (BLDC) motors are ideally suitable for EVs
because of their high power densities, good speed-torque
characteristics, high efficiency, wide speed ranges, and low
maintenance. BLDC motor is a type of synchronous motor.
It means that the magnetic field generated by the stator and
the magnetic field generated by the rotor rotation are at the
same frequency. BLDC motors do not experience the “slip”
which is normally seen in induction motors. However, a BLDC
motor requires relatively complex electronics for control. As
illustrated in Fig. 1, in a BLDC motor, permanent magnets are
mounted on the rotor, with the armature windings being fixed
on the stator with a laminated steel core. Rotation is initiated
and maintained by sequentially energy opposite pairs of pole
windings that are said as form phases. Knowledge of rotor
position is critical to sustaining the motion of the windings