1. GOVERNMENT COLLEGE OF ENGINEERING , JALGAON
(an autonomous institute of government of Maharashtra)
DEPARTMENT OF ELECTRICAL ENGINEERING
COURSE NAME :- AC Machine
COURSE CODE :- EE301U
TOPIC COVERED :- Stepper Motor
PRESENTED BY
Samiksha Bhasme :- (2031004)
Akshata Bhajipale:- (2132204)
GUIDED BY :-
M.R.Bachawad mam
2. CONTENTS
• Introduction of the Stepper motor
• Principle of the Stepper motor
• Classification of the Stepper motor
• Advantages of the Stepper motor
• Applications of the Stepper motor
• References
3. Introduction
• An electromechanical, digitally pulse operated motor which operated and controlled in step by
step rotation, is called stepper motor.
• A stepper motor, also known as step motor or stepping motor, is a brushless DC electric motor
that divides a full rotation into a number of equal steps.
• A standard motor will have a step angle of 1.8 degrees with 200 steps per revolution.
• STEP ANGLE:-
The angle by which the rotor of a stepper motor moves when one pulse is applied to
the(input) stator is called step angle.
Step Number or Resolution = Number of Steps
Number of revolution of the rotor
4. Principal of stepper motor
The operation of this motor works on the principle that
unlike poles attract each other and like poles repel each
other. When the stator windings are excited with a DC
supply, it produces magnetic flux and establishes the
North and South poles.
5. Classification of stepper motor
Permanent
Magnet
• Magnetic
Rotor
Variable
Relectance
• Non-magnetic,
geared rotor
Hybrid
• Combines
characteristics
from PM and
VR magnetic
,geared rotor
6. Permanent magnet (Rotor)
• 1. Permanent Magnet (Rotor)Operating
principal
• we consider A and A’ fed from positive pulse
then rotor a line with stator pole.
• In the next step give positive pulse to B and
B’.
• Then rotor start moving in discrete step or
some specific angle.
• Pulses are control by microcontroller.
• If we feed the coils with pulses which are
periodically repeated the rotor will turn step
by step at synchronous speed of rotation.
• The residual magnetism in the permanent
magnet material produce detent torque.
7. Single stack variable reluctance
• Operating principal of single stack Variable reluctance
motor
• This type of stepper motor employs the principal of
minimum reluctance path.
• It has 4-phase,4-stator,2-tooth rotor and one variable
reluctance.
• It is connected with d.c source as shown in figure.
• When phase S(A) is excited the rotor aligns with the
axis of phase S(A),now switch S(A) off and S(B)
switched on.
• The Rotor moves through 90 degree and align with the
resultant air gap field which lies along with the phase
S(B) and so on the rotor start moving.
• Step angle = 360/(q*Nr)
Where, q = No of Phase
Nr = No of rotor teeth
Torque = (1/2) * (I*I) * (dL/d θ)
8. MULTI-STACK VARIABLE RELUCTANCE
• Its principal is same as single
stack variable stepper motor.
• In the given figure it is side
view.
• In this motor,rotor have a
common shaft and stator
have a common frame.
• It produce more torque.
9. HYBRID STEP MOTOR
• Operating principal and
working .
• It operates on the combined
principal of the permanent
magnet and variable
reluctance stepper motor, so
this motor is called hybrid
motor.
10. ADVANTAGES OF STEPPER MOTOR
• They have a low power requirements due to presence of permanent magnet in the
rotor. Due to use of permanent magnet the rotor has high detent torque.
• Low cost for control achieved .
• High torque at startup and low speeds .
• Simplicity of construction .
• Can operate in an open loop control system .
• Low maintenance .
• Will work in any environment .
• Can be used in robotics in a wide scale.
• High reliability
11. APPLICATION OF STEPPER MOTOR
• The stepper motor is used for precise positioning with a motor like hard disk
drives, robotics, telescopes and some toys.
• Industrial Machines-Stepper motors are used in automotive gauge and machine
tooling automated production equipments.
• Security-New surveillance products for the security industry
• Medical-Stepper motors are used inside medical scanner , sampler and also found
inside digital dental photography
12. REFERENCES
• Electrical Machines by Ashfaq Hussain.
• Theory and performance of Electrical Machines by J.B.Gupta and S.K.Kataria.
• www.electrical4u.com
• https://www.electricaltechnology.com
• www.circuitglobe.com
• www.google.com
• https://www.engineersgarage.com
