AC series motor for robotics application.ppt

AC Servo motor with controller

1. AC Series Motor

4. CONTENTSCONTENTS
Single phase commutator motor
AC series motor
Construction & working principle
Applications
Universal motor
Working principle
Advantages & disadvantages
Applications

5. Types of Single phase commutator motorTypes of Single phase commutator motor
AC series motor
Universal motor

6. AC Series MotorAC Series Motor
Series motor
Good torque speed characteristics - Railway service
D.C series motor
Class of work service
street railway cars & trolley coaches
A.C system
more convenient & economical to transmit
the A.C power

7. Construction & Working principle:Construction & Working principle:

Armature & field are interconnected like in D.C series motor

DC series motor - direction of the torque developed is
determined by both field polarity and the direction of current
through the armature T α Φ Ia
Polarities changed for both armature and field-direction of
torque remains constant

A.C series motor- direction of torque remains unchanged for
all cycles


8. Problems arise when motor on ac supply:Problems arise when motor on ac supply:
 Increase eddy current loss
 Increase reactance drop of armature & field windings
Low power factor
Sparking in the brushes

9. Design considerations for efficient operationDesign considerations for efficient operation
Yoke & poles laminated to minimize the eddy current loss
Field circuit designed for much lower reactance to reduce the
voltage drop and improve the power factor
Get required torque – no of armature coils should be increased
Increased no of armature coils-increase armature reaction and
motor commutation problems armature reactance
Compensating winding reduces the armature reaction effect

10. Series motor inductively compensated
winding

11. Series motor conductively compensated
winding

12. Speed torque characteristicsSpeed torque characteristics

13. ApplicationsApplications
High starting torque- used in railway systems for
electric locomotive

14. Universal MotorUniversal Motor
Small motors used on both a.c or d.c supply is called
universal motor
Fractional kW ratings
Commercial frequency and voltage is applicable
Construction is same as that of A.C series motor

16. Operation of Universal MotorOperation of Universal Motor
Develop unidirectional torque
Manufactured into two types
Concentrated pole, Non Compensated type (Low h.p)
Distributed winding Compensated Type(High h.p)

18. •Concentrated pole, Non compensated typeConcentrated pole, Non compensated type

19. Compensated Type (High H.P)Compensated Type (High H.P)

20. AdvantagesAdvantages
•High speed from 3600 r.p.m to around 20,000 r.p.m.
•High power output
•High torque
•Variable speed

21. DisadvantagesDisadvantages
•Increased service equipment
•High noise at high speed
•Audio & television interference

22. ApplicationsApplications
Portable drills, hair dryers, grinders, table-fans,
blowers, polishers, kitchen appliances ets.
They are also used in where the load requires high values of
speed.
Universal motors of a given horse power rating are
significantly smaller than other kinds of a.c. motors
operating at the same frequency

24. One More Square Puzzle
Seven matchsticks form two squares as shown in the illustration.
Move three matchsticks to get three squares. You can rotate
matchsticks, but you can't overlap and/or damage them.

25. One More Square Puzzle - Solution

31. A.C series motor
D.C series motor operate on a.c supply
direction of torque remains unchanged for all cycles
Design considerations
Laminated magnetic circuit
Reduce the no of turns of field winding
Incresae the armature coils
Reduce the armature reaction-compensating winding

32. Universal Motor
Operate on either a.c or d.c supply
Fractional Kw rating
Types
Un compensated –Low H.P
Compensated-High H.P
Applications-Mixi,grinder,hair dryer
high speed required

35. Multiple Choice QuestionsMultiple Choice Questions
1.A universal motor runs at
 
a.Higher speed with dc supply and with less sparking
b.Higher speed with ac supply and with less sparking
c.Same speed with both ac and dc supplies
d.Higher speed with ac supply but with increased sparking at the
brushes
2. For the same rating which motor has the highest starting torque?
 
a.Universal motor
b.Split phase motor
c.Synchronous motor
d.All have identical starting torque