Electrical Machines-I (B.Tech)

Magnetic circuits, transformers, DC machines and electromechanical energy conversion.

6 MonthsDuration 5Chapters40Topics

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Syllabus · पाठ्यक्रम

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01Unit 1: Principles of Electromechanical Energy Conversion 6 topics

Magnetic circuits and flux linkage
Energy stored in a magnetic field
Field energy and co-energy
Force in singly excited systems
Torque in singly and doubly excited rotating systems
Reluctance torque

02Unit 2: Single-Phase Transformer 10 topics

Construction and types
EMF equation and turns ratio
Phasor diagrams on no load and on load
Equivalent circuit referred to primary and secondary
Losses, efficiency and condition for maximum efficiency
All-day efficiency
Open-circuit and short-circuit tests
Voltage regulation
Sumpner's (back-to-back) test
Auto-transformer

03Unit 3: Three-Phase Transformers 8 topics

Three-phase transformer construction
Star and delta connections
Vector groups (Yy0, Dd0, Dy1, Dy11)
Parallel operation and load sharing
Open-delta (V-V) connection
Scott connection (three-phase to two-phase)
Three-winding transformer and tertiary winding
Tap changers

04Unit 4: DC Machines and DC Generators 8 topics

Construction of DC machines
Lap and wave armature windings
EMF equation
Armature reaction
Commutation, interpoles and compensating winding
Types of DC generators
Open-circuit (magnetisation) and load characteristics
Voltage build-up and critical resistance

05Unit 5: DC Motors 8 topics

Back EMF and torque equation
Characteristics of shunt, series and compound motors
Starting and three-point / four-point starters
Speed control: armature, field and Ward-Leonard
Losses and efficiency
Swinburne's test
Hopkinson's test
Electric braking

About

You will be able to

Explain electromechanical energy conversion using field energy and co-energy and find force and torque
Draw the equivalent circuit and phasor diagrams of a single-phase transformer
Calculate losses, efficiency and voltage regulation from OC and SC test data
Explain three-phase transformer connections, vector groups and parallel operation
Derive the EMF and torque equations of DC machines and explain armature reaction and commutation
Select starting and speed-control methods for DC motors and estimate efficiency by Swinburne's and Hopkinson's tests

Who it is for

B.Tech Electrical Engineering students of Semester 4 under AKTU
Students preparing for AKTU sessional tests, the end-semester examination and GATE basics of machines

What you need

Basic Electrical Engineering and Electromagnetic Field Theory of the first three semesters

Questions

Which syllabus is followed?

The current AKTU (Dr. A.P.J. Abdul Kalam Technical University, Lucknow) B.Tech syllabus of Electrical Machines-I (Electrical Engineering, Semester 4). If your university or college follows a different syllabus, the centre teaches from your own university syllabus.

How is the subject examined?

AKTU assesses it through sessional tests, assignments and attendance, and an end-semester university examination; the centre covers every unit with theory, derivations and numericals.

Are previous-year questions practised?

Yes. Unit-wise AKTU previous-year questions, short-answer questions and the test series are solved in class.