AC MACHINES-1 (66761) Theory
11. Recognize the concept of development of rotating magnetic field and torque in rotor.
Recognize the concept of development of rotating magnetic field and torque in rotor.
11.1 Explain the development of rotating magnetic field for three phase induction motor.
11.2 Express the deduction of the formula
R
5m 1. .
11.3 Demonstrate the principle of rotation of a 3-phase motor.
11.4 Clarify starting torque, running torque and maximum torque.
11.5 Explicit the deduction of the equation of starting torque, running torque and maximum
torque.
11.6 Describe the condition for maximum torque at running and starting condition.
11.7 Mention the relation between torque and rotor power factor.
11.8 Explain the relation between torque and speed.
11.9 Draw the torque speed curve.
11.10 Explain the effect of changing the voltage on torque and speed.
12 Perceive the concept of Power stages of induction motor.
12.1 List the losess in 3-phase induction motor.
12.2 Indicate different stages of power developed in an induction motor.
12.3 Solve Energy stages related problems.
13 Understand the equivalent circuit and maximum Power output of an induction motor.
13.1 Explain the equivalent circuit of an induction motor.
13.2 Clarify maximum power output of an induction motor.
13.3 Express the deduction of the maximum power output
RL
Zo
14 Realize the principle of starting of a 3-phase induction motor.
14.1 Explain the purpose of starter.
14.2 List the starters used for starting 3-phase induction motor.
14.3 Describe the direct Online starter method, Start-delta starter method (manual and
automatic), Auto transformer starter method of starting squirrel cage induction motor.
14.4 Illustrate the rheostat method of starting slip ring induction motor. .
15 Understand the principle of speed control of induction motor.
15.1 List the methods of speed control of 3-phase induction motor.
15.2 Describe speed control by changing applied voltage, changing applied frequency and
changing stator poles.
15.3 Describe rheostat control method, concatenation method & injecting emf in rotor
circuit method.