SR motors do not contain magnets and are constructed such that both the stator and rotor have salient poles.
The motor is driven by a sequence of current pulses applied at each phase, which requires control electronics for operation. The SR motor works on the principle that the magnetic circuit tries to minimize the reluctance (air gap distance) of the magnetic circuit. The magnetic field creates a force on the rotor so that its poles line up with the poles of stator phase.
ADVANTAGES OF SWITCHED RELUCTANCE MOTOR:
• Low cost resulting from simple construction.
• High reliability.
• High fault tolerance.
• Heat generated in stator is easy to remove.
• High-speed operation possible.
DRAWBACKS OF SWITCHED RELUCTANCE MOTOR:
• Acoustically noisy.
• High vibration.
• Magnetic non-linearities make smooth torque control difficult.
• Dependent on electronic control for operation.