Anna University Chennai 2010-7th Sem B.E Electrical and Electronics Engineering /B.Tech , il/ , ester, , EE1001 – SPECIAL ELECTRICAL MACHINES - Question Paper

Part A
(10*2=20)

1.What are the kinds of rotor available in synchronous reluctance motor?
2.What is vernier motor?
3.Give the classification of stepper motor.
4.Define the term slewing.
5.Draw the speed-torque characteristics of switched reluctance motor.
6.List any 4 applications of switched reluctance motor.
7.What are the advantages of PMBLDC motor?
8.Give the expression for the emf and torque of a PMBLDC motor.
9.What is load commutation?
10.What is the magnitude of stator current in PMSM to achieve demagnetization?

Part B
(5*16=80)

11.(a) discuss the principle of operation and constructional features of various kinds of synchronous reluctance motor.(16)
(Or)
(b) discuss the circle diagram and torque speed characteristics of synchronous reluctance motor.(16)

12.(a)(i) define the operation of a variable reluctance kind stepper motor.(8)
(ii) Draw and discuss the torque pulse rate characteristics of a stepper motor.(8)
(Or)
(b)(i) discuss the working of hybrid motor with neat diagram.(8)
(ii) What is stepping angle? A VR stepper motor eight poles in the stator and they have 5 teeth in every pole. If the rotor has 50 teeth, compute the step angle and resolution.(8)

13.(a) define the Hysteresis kind and PWM kind current regulator for 1 phase of a switched reluctance motor with relevant circuit diagram.(16)
(Or)
(b)With neat diagram, discuss the microprocessor based control of switched reluctance motor.(16)

14.(a) discuss the construction and principle of operation of PMBLDC motor with neat diagram.(16) (Or)
(b)Describe the operation of power controllers for PMBLDC motor with neat diagram.(16)

15.(a) discuss the construction and performance of a permanent magnet synchronous motor with neat diagram.(16)
(b) Derive the emf and torque formula of permanent magnet synchronous motor.(16)

Earning:   Approval pending.