2. Motor construction
• Rotor
• Stator
• Air gap
• Windings

3. Parts of DC Motor

7. Series Motor
Advantages of DC series
motors:
• Huge starting torque
• Simple Construction
• Designing is easy
• Maintenance is easy
• Cost effective

8. Permanent Magnet DC Motor
• Higher efficiency since no electrical energy is used or losses
incurred for developing or maintaining the motor’s magnetic
field.
• Higher torque and power density.
• Linear torque speed charcteristics. that are more predictable.
• Better dynamic performance due to higher magnetic flux
density in air gap.
• Simplified construction and essentially maintenance-free.
• More compact size.
http://www.ohioelectricmotors.com/permanent-magnet-dc-motors-649#ixzz2sttph8bA

9. Advantages
simple torque and speed control without
sophisticated electronics

10. General Torque Equation
Translational (linear) motion:
dt
d
JT


Rotational motion:
dt
dv
MF 
F : Force (Nm)
M : Mass (Kg )
v : velocity (m/s)
T : Torque (Nm)
J : Moment of Inertia (Kgm2 )
 : angular velocity ( rad/s )

12. Synchronous Machines

15. • Above a certain size, synchronous motors are
not self-starting motors. This property is due
to the inertia of the rotor; it cannot instantly
follow the rotation of the magnetic field of the
stator.

16. • synchronous motor produces no inherent
average torque at standstill, it cannot
accelerate to synchronous speed without
some supplemental mechanism.

17. Applications
• Synchronous motors are especially useful in applications
requiring precise speed and/or position control.
• Speed is independent of the load over the operating range
of the motor.
• Speed and position may be accurately controlled using
open loop controls, e.g. stepper motors.
• Low-power applications include positioning machines,
where high precision is required, and robot actuators.
• They will hold their position when a DC current is applied to
both the stator and the rotor windings.
• Increased efficiency in low-speed applications (e.g. ball
mills).

18. Induction Motor
• Asynchronous motor
• AC electric motor

19. Introduction
• Three-phase induction motors are the most
common and frequently encountered
machines in industry

20. Induction Motor
• The electric current in the rotor needed to
produce torque is induced by electromagnetic
induction from the magnetic field of the stator
winding.
• Does not require mechanical commutation

21. – simple design, rugged, low-price, easy maintenance
– wide range of power ratings: fractional horsepower to
10 MW
– run essentially as constant speed from no-load to full
load
– Its speed depends on the frequency of the power
source
• not easy to have variable speed control
• requires a variable-frequency power-electronic drive for
optimal speed control