Correct Answer - Option 2 : Ferromagnetic
Variable reluctance stepper motor:
It is the motor that has motion in steps with respect to increase in time and constructed of ferromagnetic material with salient poles.
- The stator of this motor consists of a three-phase wounded type. It has six salient poles with concentrated windings around each one of them.
- The rotor has 4 slots to produce the effects of 4 poles.
- The two stator windings which are in the opposite direction are connected in series. These windings are then energized by three different switches.
Principle of operation: The principle of this motor is based on the property of the flux lines which capture the low reluctance path. The stator and the rotor of the motor are aligned in such a way that the magnetic reluctance is minimum.
There are two types of the Variable Reluctance Stepper Motor.
- Single Stack Variable Reluctance Motor
- Multi Stack Variable Reluctance Motor
- High torque to inertia ratio
- High rates of acceleration
- Fast dynamic response
- Simple and low-cost machine
- Rotor construction is robust due to the absence of brushes