This introductory textbook on basic electrical engineering provides a firm foundation to the basic concepts of electrical circuits and systems. The material in the book can be considered in three parts—electric circuits (dc and ac), field parts (magnetic and electric), and electrical machines. Beginning with the fundamental concepts of electricity and electrical elements, it provides a balanced coverage of dc and ac electric circuits and electrical machines. The principles of operation of transformers, dc machines, both generator and motor including three-phase induction motors, as well as synchronous ac machines, both generator and motor, are covered in great detail. The book includes a fair number of solved illustrative examples and exercises, carefully designed to give the reader sufficient help in assimilating concepts and applying them to practical situations. The contents of the book meet the curriculum requirements of the first year undergraduate engineering programme prescribed in India.
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N K De, , formerly a faculty member in the Department of Electrical Engineering, IIT Kharagpur (1968–2007), and Principal, Narula Institute of Technology (NIT), Agarpara, Kolkata (2007–09), is now a visiting professor at the Department of Electrical Engineering, NIT. He has more than forty-two years of teaching and research experience. Besides several research papers in well-known journals, he is the co-author of Electric Drives and Problems in Electrical Machines and Electric Drives, both published by Prentice Hall, India.
Dipu Sarkar is presently a faculty member in the Department of Electrical Engineering, National Institute of Technology Nagaland. Earlier, he had taught in the Department of Electrical engineering, Narula Institute of Technology, Agarpara, Kolkata, for ten years (2003–2013). His area of specialisation is power systems, and his research interests lie in power systems operation and control, voltage stability, network reconfiguration, smart grid and applications of soft computing techniques to power engineering.
Preface
1 Introduction
1.1 Ohm’s Law
1.2 Series and Parallel Connection of Resistors
Multiple Choice Type Questions
Problems
2 DC Circuits
2.1 Definition of Basic Terms Used in DC Circuits
2.2 Kirchhoff’s Laws
2.3 Loop Current Method
2.4 Nodal Voltage Method
2.5 Circuit Theorems
2.5.1 Superposition Principle
2.5.2 Star–Delta Conversion
2.5.3 Thevenin’s Theorem
2.6 Types of Energy Sources
2.7 Conversion of a Real Voltage Source into a Real Current Source
2.8 Some Other Basic Theorems
2.8.1 Maximum Power Transfer Theorem
3 DC Transients
3.1 Transients in R-L Circuits
3.2 Transients in R-C Circuits
4 Alternating Quantities and Phasor Algebra
4.1 Generation of Sinusoidal (ac) Waveform
4.2 Average and RMS Values of Periodic Voltage or Current Waveform
4.3 Representation of Sinusoidal Signal by a Phasor
4.4 Phasor Algebra
5 AC (Single-phase) Series Circuits
5.1 Circuits using only a single element
5.1.1 Voltage, Current, Impedance, Phasor Diagram
5.2 Series Circuits
5.3 Resonance in R-L-C Series Circuits
6 Single Phase AC Parallel and Series–Parallel Circuits
6.1 Parallel Circuits
6.2 Necessity of Power Factor (PF) Improvement in AC Circuits
6.3 Series–Parallel Circuits
6.4 Resonance in Parallel Circuits
6.5 Quality Factor
7 Three-Phase Balanced Supply
7.1 Generation of Three-Phase Balanced Voltages
7.2 Three-phase Voltages for Star Connection
7.3 Relation between Phase and Line Voltages for Delta Connection
7.4 Currents in a Circuit with a Balanced Load (Star Connected)
7.5 Total Power Consumed in a Circuit with a Star Connected Balanced Load
7.6 Currents in a Circuit with a Balanced Load (Delta Connected), Fed from a
Three-phase Supply
7.7 Total Power Consumed in a Delta Connected Circuit with a Balanced Load
7.8 Measurement of Power in a Three-phase Circuit
7.8.1 Two Wattmeter Method of Power Measurement
7.8.2 Determination of the Power Factor for a Balanced Load in a Three-Phase
System
7.8.3 Power Measurement Using One Wattmeter Only for a Balanced Load
8 Electro-Magnetism and Magnetic Circuits
8.1 Magnetism
8.2 Biot–Savart Law
8.2.1 Application of Bio–Savart Law
8.3 Magnetic Circuits
8.3.1 Magnetic Circuits (Series and Series–Parallel Types)
9 Inductance
9.1 Faraday’s Laws of Electro-magnetic Induction
9.2 Inductance
9.3 Energy Stored in the Inductor
9.4 Series and Parallel Connection of Inductances
9.5 Magnetic Losses
10 Eletrostatics and Capacitance
10.1 Coulomb’s Laws
10.2 Electric Field Intensity due to a Point Charge
10.3 Electric Field
10.4 Electric Flux and Flux Density
10.5 Electric Potential and Potential Difference
10.6 Potential Gradient and Electric Field Intensity
10.7 Gauss’ Theorem
10.8 Capacitance
10.9 Types of Capacitors
10.10Series and Parallel Connection of Capacitors
10.11Energy Stored in a Capacitor
10.12Parallel Plate Capacitor
10.13Capacitance of an Isolated Sphere
10.14Capacitance of Concentric Spherical Conducting Plates
10.15Capacitance of Concentric Cylindrical Conductors
10.16Capacitance of Parallel Conductors
11 Transformers
11.1 Construction
11.2 EMF Equation
11.3 Operation on No-load and Load
11.4 Equivalent Circuit
11.5 Regulation
11.6 Losses and Efficiency
11.7 Testing
12 DC Machines
12.1 Construction
12.2 EMF Equation for DC Machines
12.3 Types of Connections Used for Field Windings in DC Machines
12.4 Open Circuit (No-load) Characteristic of a DC Shunt or Self-excited Generator
12.5 Load Characteristics of Different Types of DC Generators
12.6 Torque Equation for a DC Machine
12.7 Load Characteristics of DC Motors
12.8 Starters for DC Shunt Motors
12.9 Methods Used for Speed Control of DC Motors
12.10Losses and Efficiency of DC Machines
13 Three-phase Induction Motors
13.1 Production of Rotating Magnetic Field in a Three-phase Induction Motor
13.2 Construction of a Three-phase Induction Motor
13.3 Principle of Operation
13.4 Equivalent Circuit of a Three-phase Induction Motor
13.5 Torque–Speed Characteristics of a Three-phase Induction Motor
13.6 Need for Starters in IM
13.6.1 Starters for Squirrel Cage IM
13.6.2 Rotor Resistance Starters for Slip-ring (Wound Rotor) IM
13.7 Methods of Speed Control for a Three-phase IM
14 Synchronous Machines
14.1 Construction
14.2 EMF Equation
14.3 Synchronous Impedance
14.4 Determination of Regulation of Synchronous Generator Using the Synchronous
Impedance Method
14.5 Motor Operation of Synchronous Machines
14.6 V-curve
15 Electrical Measuring Instruments
15.1 Classification of Measuring Instruments
15.2 Principles of Operation of Indicating Instruments
15.3 Different Types of Indicating Instruments
15.3.1 Permanent Magnet Moving Coil (PMMC) Instrument
15.3.2 Moving Coil Dynamometer Instruments
15.3.3 Dynamometer Wattmeter
15.3.4 Moving Iron Instrument
Appendix
Index