EE010602 Induction Machines B.Tech Model Question Paper : mgu.ac.in

Name of the University : Mahatma Gandhi University
Department : Electrical and Electronics Engineering
Degree : B.Tech
Subject Code/Name : EE 010 602/Induction Machines
Sem : VI
Website : mgu.ac.in
Document Type : Model Question Paper

Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/mgu.ac.in/5142-EE%20602.pdf

MGU Induction Machines Model Question Paper

Sixth Semester :
B.Tech Electrical and Electronics
EE 010 602 Induction Machines :

Related : MGU EE010706L06 Special Electrical Machines B.Tech Model Question Paper : www.pdfquestion.in/5096.html

Max: 100 Marks
Time:3Hrs

PART A

1. Explain the constructional details of 3-phase squirrel cage induction motor.
2. Explain the frequency control of 3-phase induction motor
3. Explain the Phasor diagram of induction generator
4. Explain working principle and applications of universal motor
5. With a neat diagram, explain the operation of linear induction motor 3*5=15

PART B

1. Explain cogging and crawling and methods of their elimination
2. Explain star- delta starter with a neat diagram
3. Explain capacitor start – capacitor run single-phase induction motor.
4. Explain the constructional details and working of hysterisis motor
5. Explain BLDC Motor 5*5=25

PART C

6. 20hp, 440V, 50HZ, 3, 4 pole star connected IM gave the following test results
No load test: 440V, 1110W, 9.2A
Blocked rotor test: 150V, 4.5KW, 40A
Draw the circle diagram and determine at full load 1) line current ii) pf iii) speed and iv) efficiency at half load (12 Marks)
OR

7. a) A 6 pole, 3 phase 50Hz induction motor develops a maximum torque of 20 kg.m at a speed of 970rpm. Determine the torque exerted by the motor at 4% slip. The rotor resistance per phase is 0.5. (6 Marks)

b) The full load power input to a 3 IM is 50Kw and the slip is 3%. Neglecting stator losses, calculate the full load cu losses and total mechanical power developed. (6 Marks)

8. a) Explain the method of speed control by pole changing (6 Marks)
b) A cage induction motor when started by a star delta starter takes 200% of full load current and develops 44% of full load torque at starting. Calculate the starting current if an auto transformer with 75% tappings were employed (6 Marks)
OR

9. Design a 6 stud rotor starter for a wound rotor induction motor. The slip at full load is 2% and the stating current is 1.5 times the full load current. The resistance of rotor is 0.02 ohms per phase (12 Marks)

10. (a) Explain the working of a shaded pole induction motor. (6 marks)
(b) A 125KW, 4 pole, 50Hz, single phase induction motor delivers rated output at a slip of 6%. The total copper loss at fulI load is 25 w. Calculate the full load efficiency and the rotor copper loss caused bv the backward field. Rotational losses may be assumed to be 25W. Neglect stator copper loss. (6 Marks)
OR

11. a) Explain the construction and principle of operation of an induction generator with Phasor diagram and equivalent circuit (6 Marks)
b) Explain the working of a single-phase series motor with Phasor diagram and circle diagram. (6 Marks)

13. Explain commutator motor and Emf induced in commutator winding (12 Marks)
OR
14. Explain the working of Repulsion motor and Reluctance motor (12 Marks)

15. Explain construction, operating characteristics and principle of operation of stepper motor (12 Marks)
OR
16. Write short notes on
a) Permanent magnet reluctance motor
b) Switched Reluctance motor (12 Marks)

Syllabus

EE 010 602 Induction Machines :
Objectives :
Construction, principle of operation and performance of induction machines and special electrical machines

Module1 : (16 Hours)
Three phase induction motor: Construction-squirrel cage and slip ring motors-principle of operation-slip and frequency of rotor current-mechanical power – developed torque- phasor diagram-torque-slip curve-pull out torque-losses and efficiency.

No load and locked rotor tests-equivalent circuit-performance calculation from equivalent circuit-circle diagram-operating characteristics from circle diagram-cogging and crawling and methods of elimination.

Module 2 : (14 Hours)
Starting of three phase squirrel cage induction motor-direct on line starting-auto transformerstar delta starting- starting of slip ring motors-design of rotor rheostat-variation of starting torque with rotor resistance.

Speed control-pole changing-rotor resistance control-frequency control-static frequency conversion-Deep bar and double cage induction motor –equivalent circuit -applications of induction machines-single phasing-analysis using symmetrical components.

Module3 : (10 Hours)
Induction Generator : Theory- phasor diagram-Equivalent circuit-Synchronous Induction motor-construction-rotor winding connections-pulling into step Single phase Induction motor: Revolving field theory- equivalent circuit- torque-slip curvestarting methods-split phase, capacitor start-capacitor run and shaded pole motors.