ABSTRACT
DSP-BASED CONTROL OF PERMANENT MAGNET BRUSHLESS DC
MACHINES
9.1 Introduction
Permanent magnet alternating current (PMAC) motors are synchronous motors
that have permanent magnets mounted on the rotor and poly-phase, usually three-
phase, armature windings located on the stator. Since the field is provided by the
permanent magnets, the PMAC motor has higher efficiency than induction or
switched reluctance motors. It also draws better power factor and has higher power
density. The advantages of PMAC motors, combined with a rapidly decreasing cost
of permanent magnets, have led to their widespread used in many variable-speed
drives such as robotic actuators, computer disk drives, domestic appliances,
automotive applications, and heating-ventilating-air conditioning (HVAC)
equipment.
