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## GUJARAT TECHNOLOGICAL UNIVERSITY

Program Name: Diploma Engineering Level: Diploma Branch: Electrical Engineering / Renewable Energy Subject Code: DI04000321 Subject Name: Electrical Machines - II

| w. e. f. Academic Year:   | 2025-26   |
|---------------------------|-----------|
| Semester:                 | 4 th      |
| Category of the Course:   | PCC       |

| Prerequisite:   | Electrical  Engineering  Fundamentals,  Electric  &  Magnetic  Circuits  and  Electromagnetism                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
|-----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Rationale:      | This  syllabus  is  designed  to  provide  diploma  students  with  a  comprehensive  understanding  of  core  electrical  machines  widely  used  in  industry,  power  systems  and  commercial  applications.  It  builds  foundational  knowledge  in  the  construction,  working  principles,  performance  characteristics  and  control  methods  of  single-phase  and  three-phase  induction  motors  and  synchronous  machines. Emphasis on energy-efficient designs and modern control techniques  prepares  students  to  meet  current  industrial  standards  and  sustainability  goals.  Practical exposure through tests, maintenance, and troubleshooting equips them  with skills to ensure reliable operation and enhance machine performance. This  prepares  students  for  technical  roles  requiring  maintenance,  repair,  and  optimization  of  electrical  machines  within  evolving  energy  and  industrial  landscapes. |

## Course Outcome:

After Completion of the Course, Student will able to:

|   CO  No | Course Outcomes                                                                                                                                                                                         | RBT Level   |
|----------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------|
|       01 | Understand  the  construction,  working  and  starting  methods  of  single-phase  induction motors and select appropriate motors for various applications.                                             | A           |
|       02 | Analyze  the  construction,  working,  performance  and  control  of  three-phase  induction motors.                                                                                                    | A           |
|       03 | Analyze, evaluate,  and apply the principles, characteristics,  control  methods  and  modern  advancements  of  three-phase  synchronous  machines  for  efficient  power  generation and utilization. | A           |

*Revised Bloom's Taxonomy (RBT)

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## GUJARAT TECHNOLOGICAL UNIVERSITY

Program Name: Diploma Engineering Level: Diploma Branch: Electrical Engineering / Renewable Energy Subject Code: DI04000321 Subject Name: Electrical Machines - II

## Teaching and Examination Scheme:

| Teaching Scheme  (in Hours)   | Teaching Scheme  (in Hours)   | Teaching Scheme  (in Hours)   | Total  Credits  L+T+ (PR/2)   | Assessment Pattern and Marks   | Assessment Pattern and Marks   | Assessment Pattern and Marks   | Assessment Pattern and Marks   | Total   |
|-------------------------------|-------------------------------|-------------------------------|-------------------------------|--------------------------------|--------------------------------|--------------------------------|--------------------------------|---------|
| L                             | T                             | PR                            | C                             | Theory                         | Theory                         | Tutorial / Practical           | Tutorial / Practical           | Marks   |
| L                             | T                             | PR                            | C                             | ESE (E)                        | PA(M)                          | PA(I)                          | ESE(V)                         | Marks   |
| 3                             | 0                             | 2                             | 4                             | 70                             | 30                             | 20                             | 30                             | 150     |

## Course Content:

|   Unit  No. | Content                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |   No. of  Hours | % of  Weightage   |
|-------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|-------------------|
|           1 | Single Phase Induction Motors  Contents:   Necessity of Single-Phase Induction Motor   Double Field Revolving Theory   Self-Starting  Techniques  (Phase  Splitting,  Shaded  Pole,  Reluctance)   Construction  and  Working  Principle,  Torque-Speed  Characteristics   Types  of  Single-Phase  Induction  Motors:  Capacitor  Start- Induction  Run,  Capacitor  Start-Capacitor  Run,  Shaded  Pole  Motor, Repulsion Type Motor, Universal Motor   Motor Selection for Different Applications   Maintenance of Single-Phase Induction Motors |              07 | 16 %              |
|           2 | Three Phase Induction Motors  Contents:    Classification of Three Phase AC Machines   Construction of Squirrel Cage and Slip Ring Induction Motors   Rotating Magnetic Field and Synchronous Speed   Working  Principle  and  Comparison  (Squirrel  Cage  vs.  Slip  Ring)   Rotor  Behaviour:  Speed,  Slip,  Frequency,  Power  Factor  (Standstill & Running)   Slip Measurement Techniques                                                                                                                                                     |              20 | 44 %              |

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## GUJARAT TECHNOLOGICAL UNIVERSITY

## Program Name: Diploma Engineering Level: Diploma Branch: Electrical Engineering / Renewable Energy Subject Code: DI04000321 Subject Name: Electrical Machines - II

|    |  Torque  Analysis:  Starting,  Full  Load,  Maximum  Torque  &  Ratios   Torque-Slip Characteristics   Losses and Power Stages in Induction Motor   Necessity  and  Types  of  Starters  (Stator  Resistance,  DOL,  Autotransformer, Star-Delta, Rotor Resistance, Soft Starters)   Speed Control Methods: Stator Voltage, Pole Changing, Rotor  Resistance, VVVF   Induction Motor as Transformer (Phasor Diagram)   Four Quadrant Operation & Power Flow   Motor Selection based on Load Requirements   Different  Standards  and  Specifications  of  Three-Phase  Induction Motors (IS, IEC, NEMA, Efficiency Classes, Frame  and Mounting Standards)   Maintenance of Three Phase Induction Motors                                                                                          |    |      |
|----|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----|------|
|  3 | Three Phase Synchronous Machines Contents:    Constructional Details of Three Phase Synchronous Machines   Principle of Operation of Three Phase Synchronous Motors   Load Angle Significance   Torque Characteristics (Starting, Running, Pull-in, Pull-out)   V-Curves and Inverted V-Curves   Methods of Starting Synchronous Motors   Hunting and Phase Swinging   Applications and Power Factor Improvement   Working Principle of Alternators   Types of Alternators and Brief Comparison (Turbo, Hydro)   Speed and Frequency Relation   Armature Windings: Short Pitch & Distribution Factor   Brushless Excitation System   E.M.F. Equation of Alternator   Synchronous Reactance and Armature Reaction   Voltage  Regulation  Methods  (Direct  Loading,  Synchronous  Impedance) | 18 | 40 % |

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## GUJARAT TECHNOLOGICAL UNIVERSITY

## Program Name: Diploma Engineering

## Level: Diploma

## Branch: Electrical Engineering / Renewable Energy

Subject Code: DI04000321

Subject Name: Electrical Machines - II

|  Synchronisation  of  Alternators:  Definition,  Necessity,  and  Conditions   Introduction of various Standards and Specifications of Three- Phase  Synchronous  Machines  (IS,  IEC,  NEMA,  Efficiency  Classes, Frame, and Mounting Standards)   |    |     |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----|-----|
| Total                                                                                                                                                                                                                                                  | 45 | 100 |

## Suggested Specification Table with Marks (Theory):

## Distribution of Theory Marks(in %)

| R Level   | U Level   | A Level   | N Level   | E Level   | C Level   |
|-----------|-----------|-----------|-----------|-----------|-----------|
| 25 %      | 35 %      | 40 %      | -         | -         | -         |

Where R: Remember; U: Understanding; A: Application, N: Analyze and E: Evaluate C: Create (as per Revised Bloom's Taxonomy)

## References/Suggested Learning Resources:

## (a) Books:

|   1. | Theraja  B.  L.,  'Electrical  Technology  Vol-II  (AC  and  DC  machines)',  S.  Chand  and  Co.  Ltd.,  New Delhi, ISBN: 9788121924375.   |
|------|---------------------------------------------------------------------------------------------------------------------------------------------|
|    2 | Gupta  J.  B.,  'Theory  &  Performance  of  Electrical  Machine',  S-K-Kataria,  ISBN-13:  978- 9350142776                                 |
|    3 | Dr. P. S. Bimbhra, Electrical Machinery, Khanna Publications, ISBN: 978-9389139105.                                                         |
|    4 | Kothari  D.  P.  and  Nagrath,  I.  J.,  'Electrical  Machines',  McGraw  Hill  Education.  New  Delhi,  ISBN: 9780070699670                |
|    5 | Ashfaq Husain, Electric Machines, Dhanpat Rai & Co. (P) Ltd., ISBN: 978-8177001662.                                                         |
|    6 | Mehta V. K. and Mehta, Rohit, 'Principles of Electrical Machines', S. Chand and Co. Ltd., New  Delhi, ISBN: 9788121930888.                  |
|    7 | Mittle  V.  N.  and  Mittle,  Arvind.,  'Basic  Electrical  Engineering',  McGraw  Hill  Education,  New  Delhi, ISBN: 9780070593572.       |
|    8 | Bhattacharya  S.  K.,  'Electrical  Machines',  McGraw  Hill  Education,  New  Delhi,  ISBN:  9789332902855.                                |

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## GUJARAT TECHNOLOGICAL UNIVERSITY

Program Name: Diploma Engineering Level: Diploma Branch: Electrical Engineering / Renewable Energy Subject Code: DI04000321 Subject Name: Electrical Machines - II

## (b) Learning Websites &amp; Web-Portals:

|   Sr.  No. | Web-Link of Websites / Web-Portal                                                      | Description                                                                                                                                       |
|------------|----------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------|
|          1 | https://www.youtube.com/watch?v=exfUn nxnGEw&list=PLbRMhDVUMngcDrGXlt -hX-ekpldUlC2b6  | NPTEL Course on Electrical Machines - II  NOC Jan 2019: Electrical Machines - II  NPTEL IIT Kharagpur                                             |
|          2 | https://www.electrical4u.com/electrical- engineering-articles/electric-motor/          | Electric Motor - A free site with clear articles on  induction motors, synchronous machines                                                       |
|          3 | https://www.youtube.com/playlist?list=PLq QE5uI_2_7k0601t2dt_3lHKqTjZpd4p              | Single Phase Induction Motors                                                                                                                     |
|          4 | https://www.youtube.com/playlist?list=PLq QE5uI_2_7nMuEfkgX358-sJlI3jpJG2              | Three Phase Induction Motors                                                                                                                      |
|          5 | https://www.youtube.com/playlist?list=PLq QE5uI_2_7k2QDlpPuxKQb5CxJLtNdGT              | Three Phase Synchronous Motors                                                                                                                    |
|          6 | https://www.youtube.com/playlist?list=PLq QE5uI_2_7mzaJgqV25wNghzlbAljAct              | Alternators                                                                                                                                       |
|          7 | https://electrical-engineering- portal.com/category/electrical-machines                | Electrical-Engineering Portal (EEP) - Technical  articles on electrical machines - Good for deeper  articles, case studies, maintenance practices |
|          8 | https://www.iec.ch/government- regulators/electric-motors?utm                          | IEC / NEMA comparisons, nameplate standards -  Helps understanding of how standards differ and  how nameplate data is formatted                   |
|          9 | https://www.sogaenergyteam.com/iec- asynchronous-motors-technical- specifications/?utm | Induction motor standards and specifications-   SOGA (IEC induction motor specs - Shows IEC  standards, frame sizes, duty, mounting, etc.         |
|         10 | https://innovationspace.ansys.com/product/ electrical-machines-and-magnetic-fields/    | To enhance understanding of electrical machines  with various tutorials                                                                           |

## Suggested Course Practical List:

The  following  Practical  Outcomes  (PrOs)  are  the  sub-components  of  the  Course  Outcomes  (COs). Some of the PrOsmarked '*' are compulsory, as they are crucial for that particular CO at the 'Precision Level' of Dave's Taxonomy related to 'Psychomotor Domain'.

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## GUJARAT TECHNOLOGICAL UNIVERSITY

## Program Name: Diploma Engineering Level: Diploma

## Branch: Electrical Engineering / Renewable Energy

Subject Code: DI04000321

Subject Name: Electrical Machines - II

|   Sr.  No. | Practical Outcomes /Title of experiment                                                                                                                                                                                                                 | CO1   | CO2   | CO3   |
|------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------|-------|-------|
|          1 | Identification of parts and demonstration of direction reversal in  single-phase induction and universal motors (ceiling fans/ mixer  motor).                                                                                                           | √     |       |       |
|          2 | Test the ceiling fan to identify starting and running winding with  capacitor connection.                                                                                                                                                               | √     |       |       |
|          3 | Direct  load  test  on  single-phase  induction  motor  to  determine  efficiency  and  speed  regulation;  plot  curves  with  respect  to  output power.                                                                                              | √     |       |       |
|          4 | Identification  of  parts,  interpretation  of  nameplate  and  function/materials  for  three-phase  squirrel  cage  and  slip  ring  induction motors.                                                                                                |       | √     |       |
|          5 | Demonstrate  reversal  of  direction  of  rotation  for  three-phase  induction motors.                                                                                                                                                                 |       | √     |       |
|          6 | Connect  and  run  three-phase  squirrel  cage  induction  motors  using DOL, star-delta, and autotransformer starters.                                                                                                                                 |       | √     |       |
|          7 | Measure slip of a three-phase induction motor using tachometer,  and stroboscope.                                                                                                                                                                       |       | √     |       |
|          8 | Perform direct load (brake) test on three-phase induction motor  and  plot  (i)  efficiency  vs  output,  (ii)  power  factor  vs  output/motor current, and (iii) torque-slip/speed characteristics.*                                                  |       | √     |       |
|          9 | Conduct no-load and blocked-rotor tests on three-phase squirrel  cage induction motor to determine equivalent circuit parameters  and  calculate  iron  and  copper  losses.  Plot  circle  diagram  using  data from no-load and blocked-rotor test. * |       | √     |       |
|         10 | Control speed of three-phase squirrel cage or slip ring induction  motors  by  (i)  auto-transformer,  (ii)  rotor  resistance  (iii)  VVVF  drive (VFD).                                                                                               |       | √     |       |
|         11 | 1 5  Direct  loading  test  on  a  three-phase  alternator  to  determine  voltage regulation and efficiency with various types of loads. *                                                                                                             |       |       | √     |
|         12 | 1 6  Perform  open  circuit  and  short  circuit  tests  on  three-phase  alternator  to  determine  synchronous  impedance,  efficiency,  and                                                                                                          |       |       | √     |

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## GUJARAT TECHNOLOGICAL UNIVERSITY

## Program Name: Diploma Engineering

## Level: Diploma

## Branch: Electrical Engineering / Renewable Energy

## Subject Code: DI04000321

## Subject Name: Electrical Machines - II

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|    | voltage regulation. *                                                                                                    |    |
|----|--------------------------------------------------------------------------------------------------------------------------|----|
| 13 | 1 9  Perform parallel operation and synchronization of two alternators  (synchronize with infinite bus bar).             | √  |
| 14 | 2 0  Construct  'V'  curves  of  synchronous  motor  at  different  load  conditions to analyze effect of excitation.  * | √  |
| 15 | 2 1  Demonstrate use of synchronous motor to improve power factor.                                                       | √  |

* Compulsory Performance

Subject In-charge can add Performance Experiments only.

## Suggested List of Laboratory/Learning Resources Required:

|   Sr.  No. | Suggested Equipment Name with Specifications                                                                               |
|------------|----------------------------------------------------------------------------------------------------------------------------|
|          1 | Three Phase Induction Motor 3 hp / 5 hp, 415 V, 50 Hz, 1440 RPM Squirrel Cagetype  coupled with suitable DC Shunt Machine. |
|          2 | Three Phase Induction Motor 3 hp / 5 hp, 415 V, 50 Hz, 1440 RPM Squirrel Cagetype  with Brake and Pulley arrangement.      |
|          3 | Three Phase Induction Motor 3 hp / 5 hp, 415 V, 50 Hz, 1440 RPM Slip Ring type.                                            |
|          4 | Stroboscope or relative Mobile app (e.g. Strobolight/RPM meter).                                                           |
|          5 | Auto Transformer: 3-Phase, 5kVA, 0 to 470V.                                                                                |
|          6 | Ammeters MI Type: AC/DC 0-5-10A, 0-10-20A.                                                                                 |
|          7 | Voltmeters MI Type: AC/DC, 0-150/300V, 0-250/500V.                                                                         |
|          8 | Clip on Meter Digital/Analog.                                                                                              |
|          9 | Digital Multimeter with standard makes for measurements.                                                                   |
|         10 | Tachometers: Contact and non-contact types: 100 to 10000 RPM.                                                              |
|         11 | Wattmeters: Single Phase, Single Element, 2.5/5A, 200/400V.                                                                |
|         12 | Wattmeters: Three Phase Double Element, 5/10A, 250/500V.                                                                   |
|         13 | Low Power Factor Wattmeter: Single Phase, 2.5/5A, 250/500V.                                                                |
|         14 | Single Phase Induction Motor, Permanent Capacitor (single value), 1 hp, 230 V, 50Hz,  1440 RPM.                            |

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## GUJARAT TECHNOLOGICAL UNIVERSITY

## Program Name: Diploma Engineering

## Level: Diploma

## Branch: Electrical Engineering / Renewable Energy

Subject Code: DI04000321

## Subject Name: Electrical Machines - II

|   15. | Star- Delta Starter (Auto/Manual), DOL Starter, VFD for 3 to 5 hp Motors.                                            |
|-------|----------------------------------------------------------------------------------------------------------------------|
|    16 | Ceiling Fan 230V preferably dismantled.                                                                              |
|    17 | Mixer Grinder (as a Universal Motor) 230V, 500W, 2800RPM.                                                            |
|    18 | Frequency Meter.                                                                                                     |
|    19 | Load Bank: Resistive, 3-Phase, 5kW, 415V.                                                                            |
|    20 | Load Bank: Inductive, 3-Phase, 20A, 415V.                                                                            |
|    21 | Load Bank: Capacitive, 3-Phase, 20A, 415V.                                                                           |
|    22 | Three Phase Alternator: 5kVA, 415V, 50 Hz, 4 Pole, 1500 RPM coupled withappropriate  DC Shunt Motor/Induction Motor. |
|    23 | Synchronizing panel - With lamps and synchroscope                                                                    |
|    24 | Three Phase Synchronous Motor: 3HP, 415 V, 1500 RPM, 4-pole, 50 Hz                                                   |

## SuggestedActivities / Project List:

## 1. Single Phase Induction Motors

## Reports / Seminars / Presentations:

-  Necessity and applications
-  Double field revolving theory
-  Self-starting techniques overview
-  Torque-speed characteristics of types
-  Motor selection criteria
-  Maintenance practices

## Projects / Activities / Demonstrations:

-  Demonstrate self-starting methods (phase splitting, shaded pole)
-  Construct capacitor start/run motor model
-  Torque-speed curve plotting for various types
-  Direction reversal and speed control demonstration
-  Maintenance and dismantling of single-phase motors

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## GUJARAT TECHNOLOGICAL UNIVERSITY

Program Name: Diploma Engineering Level: Diploma Branch: Electrical Engineering / Renewable Energy Subject Code: DI04000321 Subject Name: Electrical Machines - II

## 2. Three Phase Induction Motors

## Reports / Seminars / Presentations:

-  Classification of three phase AC machines
-  Rotating magnetic field and synchronous speed
-  Torque-slip characteristics and losses
-  Different types of starters and speed control methods
-  Standards and specifications (IS, IEC, NEMA, efficiency classes)
-  Motor selection and maintenance

## Projects / Activities / Demonstrations:

-  Starting methods: DOL, star-delta, auto-transformer
-  Slip measurement (tachometer, galvanometer, stroboscope)
-  Direct load and no-load test; torque-speed and torque-slip plots
-  Speed control using VVVF and rotor resistance
-  Circle diagram plotting
-  Direction reversal and motor mounting
-  Motor maintenance tasks

## 3. Three Phase Synchronous Machines

## Reports / Seminars / Presentations:

-  Construction and operation principles of synchronous motors and alternators
-  Load angle and torque characteristics
-  V-curves and excitation effects
-  Synchronisation and parallel operation of alternators
-  Standards and specifications (IS, IEC, NEMA)
-  Power factor improvement and maintenance

## Projects / Activities / Demonstrations:

-  Alternator open circuit and short circuit tests
-  Direct loading test and regulation calculation
-  Synchronization with infinite bus bar and parallel operation
-  Plotting V-curve and inverted V-curve
-  Synchronous motor starting and hunting phenomenon
-  Power factor improvement demonstration
-  Maintenance and inspection of alternator and synchronous motors

*******