EE1001 SPECIAL ELECTRICAL MACHINES question papers Anna university APRIL/MAY 2008 question papers Download

B.E/B.Tech DEGREE EXAMINATION APRIL/MAY 2008

Seventh Semester
                                  
(Regulation 2004)

Electrical and Electronice Engineering

EE 1001 --SPECIAL ELECTRICAL MACHINES
(Comman to B.E (Part Time) Sixth Semester Regulation 2005)
(Regulation 2004)


Time: Three hours                                                    Maximum marks: 100
Answer ALL questions

PART A (10 x 2 =20 marks)

1.What are the types of synchronous reluctance motor?

2. List the applications of vernier motor

3.What are main features of stepper motor which are responsible for its widespread use?

4.Define term 'Stepping -Angle'.

5. Draw the speed -torque characterstics of switched reluctance motor

6.What is the working principle of switched reluctance motor?.

7. Give the merits of PMBLDC motor compare to conventional motor

8. What is meant by peak recovery current im PMBLDC motor.

9. Synchronous machines with surface mount magnets have very little difference between direct axis and quadrature axis inductances.Why?

10.What is the magnitude of stator current in PMSM to achieve demagnetization?

PART B (5 x 16 = 80)

11 (a)  Describe the constructionional details and working principle of synchronous reluctance motor.

(or)

(b) (i) Draw and explain a typical torque -speed characteristics of a synchronous reluctance motor(9)

(ii) Explain the working principle of Vernier motor(7)



12.  (a) (i) Describe the operation of a variable reluctance type stepper motor.Also explain about micro stepping?(9)

(ii)Explain the working of hybrid motor(7)

(or)

(b) (i) Explain torque versus stepping rate characteristics of a stepper motor.Also explain explain about slew range and ramping(10)

(ii)What is stepping angle? Calculate the stepping angle for a 3 phase 24- pole permanent magnet type stepper motor.(6)

13 (a) (i)Explain with neat diagram, the constructional details and working principle of switched reluctance motors.(9)

(ii)Write a note on the power controllers used in switched reluctance motors?(7)

(or)

(b) Explain with neat block diagram,the microprocessor based control in switched reluctance motors.(16)

14.  (a)  (i)Explain the principle of operation of PMBLDC motors?(8)

(ii)Derive the emf equation of PMBLDC motor(8)



(or)

(b) (i) Explain with neat diagram and waveforms of the full wave inverter based PMBLDC motor(9)

(ii) Draw and explain the speed - torque characterstics of PMBLDC motor.(7)



15.  (a) (i) Derive the torque equation in PMSM(8)

(ii) Explain with phasor diagram, the measurement of L d and Lq in PMSM.(8)



(or)

(b) (i) Explain the speed - torque characteristics in PMSM.(8)

(ii) Explain the working of microprocessor based control in PMSM.(8)

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