A.C Machine-2 Syllabus Diploma in Electrical Engineering, Regulation 2010, Short Suggestion, Exam Dates, Exam Routine, Question Out, Book list with code

To provide the student with an opportunity to acquire knowledge, skill and attitude in the area of alternating current machines with special emphasis on:

  • Alternator
  • Synchronous motor
  • Single phase motor
  • Motor control

 

SHORT DESCRIPTION

Alternators: Principle, construction, emf equation, effect of load on alternator; voltage regulation, parallel operation and starting procedure of alternator; Synchronous motor: Operation, torques and excitation, Phase swinging, Starting method and uses, Power factor correction; Single phase motor: Operation of single phase motor; Operation of AC commutator motor; Motor control: Speed control of single phase motor; Starting of three phase induction motor; Controlling speed of three phase induction motor.

DETAIL DESCRIPTION

 

Theory:

 

ALTERNATORS

 

  • 1 Understand the principle of alternator.
    • 1 Explain the principle of alternator.
    • 2 Differentiate between generation in alternator and DC generator.
    • 3 Describe the methods of excitation of alternator.
    • 4 Explain the rating of alternator.
  • 2 Understand the constructional features of alternators.
    • 1 List the main parts of alternator.
    • 2 Explain the advantages of stationary armature.
    • 3 Describe the stator frame & stator core.
    • 4 Classify rotor of alternator.
    • 5 Describe salient pole type rotor and cylindrical type rotor.
    • 6 Describe damper winding.
    • 7 Describe three phase armature windings of single layer and double layer type.

 

2.8 Explain pitch factor and distribution factor.

  • 9 Explain fractional pitch, full pitch, half coiled winding and whole coiled winding.
  • 10 List the advantages of fractional pitch winding.
  • 11 Solve problems related to pitch factor & distribution factor.
  • 3 Understand the principle of emf equation.
    • 1 Describe emf equation.
    • 2 Define harmonics: fundamental, 3rd harmonic and 5th harmonic.
    • 3 Explain the effect of pitch factor and distribution factor on harmonics.
    • 4 Solve problems related to emf equation.
  • 4 Understand the effect of load and no load condition of an alternator.
    • 1 Describe alternator on no load.
    • 2 Describe the effect of resistance and leakage reactance on an alternator.
    • 3 Explain the effect of armature reaction on emf of alternator.
    • 4 Explain synchronous reactance and synchronous impedance.
    • 5 Draw the vector diagram of a loaded alternator.
    • 6 Describe resistance test, no-load lest / open circuit test and short circuit test of alternator.
    • 7 Solve problems related to synchronous reactance and synchronous impedance.
  • 5 Understand the principle of voltage regulation and efficiency of alternator.
    • 1 Define voltage regulation.
    • 2 Explain voltage regulation at unity power factor, lagging power factor and leading power factor.
    • 3 Solve problems related to voltage regulation of alternator.
    • 4 List the losses occurred in alternator.
    • 5 Explain the losses and efficiency of alternator.
    • 6 Solve problems on losses and efficiency of alternator.
  • 6 Understand the principle of parallel operation and starting procedure of alternators.
    • 1 Define the term synchronizing.
    • 2 Describe the purposes of synchronizing alternators.
    • 3 List the conditions for synchronizing.
    • 4 Describe the dark & bright lamp methods of synchronizing there phase alternator.
    • 5 Explain the method of paralleling the alternators by synchroscope.

 

6.6 Explain synchronizing current and synchronizing power.

6.7 Explain the effect of unequal voltage on synchronizing two alternators.

6.8 Describe the distributions of load between two alternators in parallel.

6.9 Describe the steps of starting an alternator.

 

SYNCHRONOUS MOTOR

  • 7 Understand the principle of operation of synchronous motor.
    • 1 Define synchronous motor.
    • 2 Explain the principle of operation of synchronous motor.
    • 3 Describe the effect of increase in load of synchronous motor.
    • 4 Draw the vector diagram.
  • 8 Understand the torques and excitation of a synchronous motor.
    • 1 List various torques of a synchronous motor.
    • 2 Describe different types of torques.
    • 3 Explain the effect of excitation on armature current and power factor.
    • 4 Construct V-curves.
    • 5 Explain V-curves.

 

 

  • 9 Understand the hunting or phase swinging of synchronous motor.
    • 1 Explain hunting or phase swinging.
    • 2 List the disadvantages of hunting.
    • 3 Explain the disadvantages and remedies of hunting.
  • 10 Understand the starting method and uses of synchronous motor.
    • 1 List the methods of starting synchronous motor.
    • 2 Describe the procedures of starting a synchronous motor.
    • 3 Compare synchronous motor with induction motor.
    • 4 List the field of application of synchronous motor.

 

POWER FACTOR CORRECTION

  • 11 Understand the principle of power factor corrections.

11.1 Define synchronous condenser.

11.2 Distinguish between synchronous motor and synchronous condenser.

11.3 Explain the methods of power factor corrections with the help of synchronous motor and synchronous condenser.

11.4 Solve problems on power factor correction related to synchronous condenser.

 

12 Understand the principle of operation of AC commutator motor.

12.1 Describe the principle operation of Schrage (poly phase commutator motor) motor.

12.2 Application of Schrage motor.

 

SINGLE PHASE MOTOR

  1. Understand the principle of operation of single phase motor.
    • 1 Explain why single phase motor is not self starting.
    • 2 Describe double revolving field theory.
    • 3 Describe cross magnetizing field theory.
    • 4 List the methods of making single phase motor self starting.
    • 5 Describe standard split phase motor.
    • 6 Describe capacitor motor.
    • 7 Describe double capacitor motor.
    • 8 Describe shaded pole motor & repulsion motor.
    • 9 Describe hysteresis motor, universal motor, reluctance motor & AC series motor.
    • 10 List the types of losses in single phase motor.
    • 11 Explain the losses and efficiency of single phase motor.
    • 12 Define stepper motor.
    • 13 Understand the working principle of stepper motor.
    • 14 Types of stepper motor.
    • 15 Advantages of stepper motor.
    • 16 Application of stepper motor.
  1. Starting and Speed Control of Single Phase Induction Motor.
  • 1 Understand the principle of speed control of single phase motor.
  • 2 List the methods of speed control of single phase motor.
  • 3 Describe the methods of speed control of single phase motor.
  • 4 Describe the method of reversing the direction of rotation of single phase induction motor using timers and relays.
  1. Understand the Starting and Speed Control of Three Phase Induction Motor.
  • 1 Describe the operation of three phase induction motor by auto-transformer action using relay and timer.
    • 2 Describe the methods of reversing the direction of rotation of three phase induction motor using relay and timer.
    • 3 Describe the methods of controlling speed of three phase induction (squirrel cage) motor by reduced voltage method using relays and timers.
    • 4 Describe the methods of controlling speed of three phase induction (wound rotor) motor by inserted resistance.

 

 

Practical:

  • 1 Perform the winding of stator of an alternator.
  • 1 Find pole pitch, pitch factor, distribution factor for developing 4 pole, 3-phase, 36 slots double layer winding of alternator.
  • 2 Draw the developed winding diagram.
  • 3 Draw the connection diagram for star connection.
  • 2 Perform the resistance test of an alternator.
    • 1 Select the required tools, equipment, machine and materials.
    • 2 Draw circuit diagram for the test.
    • 3 Connect the instruments according to the circuit diagram.
    • 4 Check the prepared circuit.
    • 5 Energize the circuit with power supply.
    • 6 Tabulate instrument readings.
    • 7 Calculate ohmic value of coil resistance and effective value of resistance.
  • 3 Perform the open circuit test of an alternator.
    • 1 List the required tools, equipment, machine and materials.
    • 2 Draw the circuit diagram for the test.
    • 3 Connect the instruments according to the circuit diagram.
    • 4 Check the prepared circuit.
    • 5 Connect the circuit with the power supply.
    • 6 Tabulate instrument readings.
    • 7 Draw Eg and If curve.
  • 4 Perform the short circuit test of an alternator.
    • 1 List the required tools, equipment, machine and materials.
    • 2 Draw the circuit diagram.
    • 3 Connect the instruments according to the circuit diagram.
    • 4 Check the developed circuit.
    • 5 Connect the circuit with the power supply.
    • 6 Tabulate the instrument readings.

 

  • 7 Calculate synchronous reactance and impedance.
  • 8 Draw Ia and If curves.
  • 5 Determine voltage regulation of an alternator through synchronous impedance method.
    • 1 List the required tools, equipment, machine and materials.
    • 2 Draw the circuit diagram.
    • 3 Connect the instruments according to the circuit diagram.
    • 4 Check the prepared circuit.
    • 5 Connect the circuit with the power supply.
    • 6 Verify If and observe the voltage at the terminals.
    • 7 Tabulate instrument readings and calculate voltage regulation.
  • 6 Determine voltage regulation of an alternator using different types of load (Resistive, Inductive and Capacitive load).
    • 1 List the required tools, equipment, machine and materials.
    • 2 Draw the circuit diagram.
    • 3 Connect the instruments according to the circuit diagram.
    • 4 Check the circuit.
    • 5 Connect the prepared circuit with the power supply.
    • 6 Tabulate the instrument reading.
    • 7 Calculate the regulation.
  • 7 Perform the parallel operation of alternators by bright lamp method.
    • 1 List the required tools, equipment, machine and materials.
    • 2 Draw the circuit diagram.
    • 3 Connect the equipment according to the circuit diagram.
    • 4 Start the prime mover.
    • 5 Check the generating voltages and phase sequences.
    • 6 Adjust the speed of the incoming machine.
    • 7 Close the switch at the full bright condition of the lamp.
  • 8 Perform the operation of synchronous motor and draw V-curves by changing field excitation.
    • 1 List the required tools, equipment, machine and materials.
    • 2 Draw the circuit diagram.
    • 3 Connect the instruments according to the diagram.
    • 4 Check the circuit.
    • 5 Change the field excitation.
    • 6 Tabulate armature and field current.
    • 7 Draw the V-curve.
  • 9 Start the three phase induction motor (squirrel cage) by auto-transformer starter using relay and timer.
    • 1 Collect tools, equipment and materials required.
    • 2 Draw connection diagram of the power, control and signal circuit.

 

9.3 Connect motor, relays, timer etc, according to the circuit diagram.

  • 4 Apply voltage to the circuit.
  • 5 Observe the operation of the motor.
  • 6 Follow safety rules.
  • 10 Start three phase induction motor (wound-rotor) by stepped resistance method using relay and timer.
    • 1 Collect tools, equipment and materials required.
    • 2 Draw the connection diagram of the power, control and signal circuit.
    • 3 Connect motor, relays and timer according to the circuit diagram.
    • 4 Apply voltage to the circuit.
    • 5 Observe the operation of the motor.
    • 6 Follow safety rules.
  • 11 Perform reversing the direction of rotation of three phase induction motor using relay and timer.
    • 1 Collect tools, equipment and materials required.
    • 2 Draw circuit diagram of the power, control and signal circuits.
    • 3 Connect motor, relay, timer etc. to the circuit.
    • 4 Apply voltage to the circuit.
    • 5 Observe the operation of the motor.
    • 6 Change the direction of rotor.
    • 7 Follow safety practices.

 

  • 12 Operate a single phase capacitor motor with a regulator.

12.1 List the tools and equipment required for the experiment.

12.2 Sketch a working diagram.

12.3 Identify two sets of coil of the motor.

12.4 Connect two sets of coil and capacitor in series with the proper set of coil so that the air blows downward.

12.5 Connect the regulator with the fan and supply power.

12.6 Change the direction of rotation of the motor by changing the connection.

 

  • 13 Start a shaded pole induction motor (on crow model).
    • 1 Draw the working diagram of the experiment.
    • 2 List the required tools and equipment.
    • 3 Connect the motor according to the diagram.
    • 4 Energize the motor with the supply voltage.
    • 5 Measure the speed by tachometer.
    • 6 Calculate the slip of the motor.