Electrical Engineering: Fundamentals / Edition 1

by Viktor Hacker, Christof Sumereder

Overview

Fundamentals of Electrical Engineering is an excellent introduction into the areas of electricity, electronic devices and electrochemistry. The book covers aspects of electrical science including Ohm and Kirkoff's laws, P-N junctions, semiconductors, circuit diagrams, magnetic fields, electrochemistry, and devices such as DC motors. This text is useful for students of electrical, chemical, materials, and mechanical engineering.

Product Details

ISBN-13:	9783110521023
Publisher:	De Gruyter
Publication date:	03/23/2020
Series:	De Gruyter Textbook
Pages:	240
Product dimensions:	6.69(w) x 9.45(h) x (d)
Age Range:	18 Years

About the Author

Viktor Hacker, Graz University of Technology, Austria. Christof Sumereder, FH Joanneum of Applied Sciences, Austria.

Table of Contents

Note of thanks vii

Preface ix

1 The basic physic principles and definitions 1

1.1 The simple circuit 1

1.1.1 The schematic diagram 2

1.1.2 Equivalent schematic 3

1.2 Electric charge Q 4

1.3 Current I 5

1.4 Mechanisms of the electric current flow 5

1.4.1 Electric conduction in metals 6

1.4.2 Electric conduction in liquids 7

1.4.3 Electric conduction in gases 8

1.4.4 Electric conduction in a vacuum 9

1.5 Current direction 11

1.6 Alternating and direct current 13

1.7 The electric field 13

1.7.1 Force on charged particle in electric field 15

1.7.2 Force between point charges 15

1.8 Electric potential φ 16

1.9 Voltage V 17

1.10 Ohm's law 18

1.10.1 Resistance R and conductance G 19

1.10.2 Temp. dependence of R, resistivity $$$, conductivity σ, temperature coefficient α 20

1.11 Energy and electrical power 21

1.12 Review questions 23

1.13 Exercises 24

2 Electrical networks 25

2.1 Kirchhoff's circuit laws 25

2.1.1 Kirchhoff's current law (KCL) or Kirchhoff's first law 25

2.1.2 Kirchhoff's voltage law (KVL) or Kirchhoff's second law 25

2.2 Series connection of resistors 26

2.3 Parallel connection of resistors 26

2.4 Combining linear and non-linear resistors 27

2.4.1 Series connection of linear and non-linear resistance 27

2.4.2 Parallel connection of linear and non-linear resistors 28

2.5 Wye (Y) connection and delta (Δ) connection 28

2.5.1 Conversion wye connection → delta connection 29

2.5.2 Conversion delta connection → wye connection 30

2.5.3 Delta-to-wye & wye-to-delta conversion in mixed circuits 30

2.6 Mixed circuits 31

2.7 Sources 32

2.7.1 Ideal voltage source / real voltage source 32

2.7.2 Ideal current source / real current source 34

2.7.3 Power adjustment 35

2.8 Voltage divider 36

2.9 The complex calculation in electrical engineering 37

2.9.1 Definitions 37

2.9.2 Application of the complex calculation in AC calculation 40

2.10 Review questions 41

2.11 Exercises 41

3 Fundamentals of electronics 43

3.1 Semiconductor materials 43

3.1.1 P-n junction 45

3.2 Semiconductor diode 46

3.2.1 Light-emitting diode (LED) 48

3.3 Zener diode 49

3.4 Resistors 51

3.5 Semiconductor resistors 53

3.5.1 Voltage dependent resistor (varistors) 53

3.5.2 Negative temperature coefficient resistors (NTC resistors) 54

3.5.3 Positive temperature coefficient resistors (PTC resistors) 56

3.5.4 Magnetic dependent resistors (MDR) 57

3.6 Hall effect sensor 58

3.7 Transistor 59

3.7.1 Basic amplifier circuits 61

3.8 Optocouplers 63

3.9 Operational amplifier 64

3.9.1 Basic circuits of an op-amp 65

3.10 Thyristor 69

3.11 Rectifier circuit 71

3.11.1 Rectified value (arithmetic mean) 72

3.12 Terms used in power electronics 73

3.13 Charging and discharging of a capacitor 73

3.14 Review questions 75

4 The stationary electric field 77

4.1 Electric current I 78

4.2 Electric potential φ 79

4.3 Electrostatic induction 82

4.4 Polarisation 83

4.5 The electric displacement flux ψ 83

4.6 Dielectric 84

4.6.1 Permittivity ε (formerly known as dielectric constant) 84

4.7 The capacitor 85

4.7.1 Electrical capacitance C 87

4.7.2 Series connection of capacitances 87

4.7.3 Parallel connection of capacitances 88

4.8 Energy content of an electric field W_el 89

4.9 Review questions 89

4.10 Exercises 90

5 The magnetic field 91

5.1 The term "field" 91

5.1.1 Right-hand screw rule 92

5.1.2 Coil rule (right-hand coil rule) 92

5.2 Magnetic field quantities 93

5.2.1 The magnetomotive force MMF 93

5.2.2 The magnetic field strength H 93

5.2.3 The magnetic flux φ 94

5.2.4 The magnetic flux density B 94

5.2.5 The permeability μ 95

5.2.6 Comparison of electric and magnetic circuit 99

5.2.7 Force exerted on a conductor in the magnetic field - Lorentz force 100

5.2.8 Left-hand rule for motors 100

5.2.9 Induction 103

5.2.10 Dynamic induction (generator principle) 103

5.2.11 Static induction (transformer principle) 104

5.2.12 Self-induction 105

5.2.13 Energy content W_magn of the magnetic field 106

5.3 Review questions 106

5.4 Exercises 107

6 Electrochemistry 109

6.1 Basic electrochemical concepts 109

6.2 Electrolysis 110

6.2.1 Electrolysis of water 111

6.2.2 Extraction of (pure) metals 111

6.2.3 Electrochemical corrosion 112

6.3 Faraday's law 112

6.4 The electrochemical series 113

6.5 Primary cells 114

6.5.1 Leclanché cell 116

6.6 Secondary cell 117

6.6.1 Lithium-ion battery 117

6.7 Fuel cell 118

6.7.1 Structure and operating principle of a fuel cell 119

6.7.2 General aspects of fuel cells 120

6.7.3 Electrochemical process 120

6.7.4 Energy balance/efficiency η_max 122

6.7.5 Loss mechanisms and overpotential 122

6.8 Electrochemical impedance spectroscopy 124

6.8.1 Cyclic voltammogram 127

6.9 Review questions 128

6.10 Exercises 129

7 Alternating current technology 131

7.1 Vector diagram of sinusoidal quantities 133

7.2 Characteristic quantities in alternating current technology 134

7.2.1 Frequency f, time period T 134

7.2.2 Phase shift φ 135

7.3 Effective value (RMS) 135

7.4 Powers in the alternating-current circuit 138

7.4.1 Active power P 138

7.4.2 Reactive power Q 139

7.4.3 Apparent power S 140

7.4.4 Correlation between S, P and Q 140

7.5 R, X_L and X_C in the alternating-current circuit 142

7.5.1 Active resistance R 142

7.5.2 Electrical impedance Z 142

7.5.3 Inductive reactance X_L in the alternating-current circuit 143

7.5.4 R and X_L in the alternating-current circuit 144

7.5.5 Capacitive reactance X_C in the alternating-current circuit 146

7.5.6 R and X_C in the alternating-current circuit 147

7.5.7 R, X_L and X_C in an alternating-current circuit 148

7.6 Resonant circuits 150

7.6.1 Series resonant circuit 151

7.6.2 Parallel resonant circuit 153

7.7 Harmonics, Fourier series representation 155

7.7.1 Generation of a square wave through overlap of sinusoidal oscillations (Fourier synthesis) 156

7.8 Three-phase current (rotary current) 158

7.8.1 Concatenation 159

7.8.2 Power of three-phase current 161

7.9 Review questions 162

7.10 Exercises 163

8 Fundamentals of measurement and regulation technology 165

8.1 Measuring electrical quantities 166

8.1.1 Electrical meters 167

8.1.2 Digital meters 168

8.2 Measuring non-electrical quantities 169

8.2.1 Length measurement, fluid-level measurement 169

8.2.2 Fluid-level measurement 171

8.2.3 Force measurement 171

8.2.4 Velocity and rotational speed 172

8.2.5 Temperature 173

8.2.6 Photometry 175

8.3 Bridge circuit 176

8.4 Control engineering 177

8.4.1 Regulation technology vs. control technology 177

8.4.2 Standard control loop and terms 178

8.4.3 Controller (I, D and PID) 180

8.5 Review questions 184

9 Electric machines 185

9.1 Transformer 186

9.1.1 Current transformation 187

9.1.2 Voltage transformation 188

9.1.3 Impedance transformation 188

9.1.4 Transmissions - Summary 188

9.1.5 Ideal transformer 189

9.1.6 Real transformer 190

9.1.7 Important characteristic values of a transformer 191

9.1.8 Types of small transformers 192

9.1.9 Three-phase transformers 193

9.2 Direct current motor (commutator motor) 193

9.2.1 Structure and functioning 193

9.2.2 Types of direct current motors 194

9.3 Three-phase asynchronous motor 196

9.3.1 Generation of a rotating field 197

9.3.2 Power P and torque M 199

9.3.3 Efficiency η 199

9.3.4 Slip s 200

9.3.5 Torque curve 200

9.3.6 Starting squirrel-cage induction motors 201

Wye-delta starting method 202

9.3.7 Applications of squirrel cage induction motors 203

9.4 Synchronous motor 203

9.5 Synchronous generator 205

9.6 Stepper motor 206

9.7 Review questions 207

9.8 Exercises 208

10 Dangers of electricity 211

10.1 Direct effects on humans 211

10.1.1 Resistance of the human body, dangerous contact voltage 211

10.1.2 Residual-current device (RCD) 214

10.2 Indirect impact on humans 215

10.3 Types of faults, voltages in case of fault 216

10.4 Review questions 217

Bibliography 219

Index 221