LITERATURE REVIEW (FYP 1)

JOURNAL 12

HYBRID MOTOR

The word Hybrid means combination or mixture. The Hybrid Stepper Motoris a combination of the features of the Variable Reluctance Stepper Motor and Permanent Magnet Stepper Motor. In the center of the rotor, an axial permanent magnet is provided. It is magnetized to produce a pair of poles as North (N) and South (S).

At both the end of the axial magnet the end caps are provided, which contains an equal number of teeth which are magnetized by the magnet.

The stator has 8 poles, each of which has one coil and S number of teeth. There are 40 poles on the stator, and each end cap has 50 teeth. The rotor teeth are perfectly aligned with the stator teeth. The teeth of the two end caps are displaced from each other by half of the pole pitch. As the magnet is axially magnetized, all the teeth on the left and right end cap acquire polarity as south and north pole respectively.

Advantages of Hybrid Stepper Motor: 

• The length of the step is smaller. 
• It has greater torque. 
• Provides Detent Torque with the de-energized windings. 
• Higher efficiency at lower speed. 
• Lower stepping rate. 

Disadvantages of Hybrid Stepper Motor: 

• Higher inertia. 
• The weight of the motor is more because of the presence of the rotor magnet. 
• If the magnetic strength is varied, the performance of the motor is effected. 
• The cost of the Hybrid motor is more as compared to the Variable Reluctance Motor.

Credit to : Prajapati Dipali, K., Raj Roshani, D., Patel Komal, C., & Hilali Marhaba, A. ( 2014). Automatic Gate Opening System For Vehicles With RFID or Password.