The calculation of short circuit currents is a central task for Power System engineers, they are essential parameters for the design of electrical equipment and installations, the operation of power systems and the analysis of outages and faults. Short-circuit Currents gives an overview of the components within power systems with respect to the parameters needed for short circuit current calculation. It also explains how to use a system of symmetrical components to analyse different types of short circuits in power systems. The thermal and electromagnetic effects of short circuit currents on equipment and installations, short-time interference problems and measures for the limitation of short circuit currents are also discussed. Detailed calculation procedures and typical data of equipment are provided in a separate chapter for easy reference, and worked examples are included throughout.Also available:Uninterruptible Power Supplies - ISBN 9780863412639Voltage Quality in Electrical Power Systems - ISBN 9780852969755The Institution of Engineering and Technology is one of the world's leading professional societies for the engineering and technology community. The IET publishes more than 100 new titles every year; a rich mix of books, journals and magazines with a back catalogue of more than 350 books in 18 different subject areas including: -Power & Energy -Renewable Energy -Radar, Sonar & Navigation -Electromagnetics -Electrical Measurement -History of Technology -Technology Management
Author(s): Jurgen Schlabbach
Year: 2005
Language: English
Pages: 336
Contents......Page 8
List of figures......Page 14
List of tables......Page 24
Foreword......Page 28
1.2 Importance of short-circuit currents......Page 30
1.3 Maximal and minimal short-circuit currents......Page 32
1.4 Norms and standards......Page 33
2.2 Complex calculations, vectors and phasor diagrams......Page 40
2.3 System of symmetrical components......Page 43
2.4 Equivalent circuit diagram for short-circuits......Page 53
2.5 Series and parallel connection......Page 56
2.6 Definitions and terms......Page 59
2.7 Ohm-system, p.u.-system and %/MVA-system......Page 61
2.8 Examples......Page 63
3.2 Equipment in a.c. systems......Page 74
3.3 Equipment in d.c. systems......Page 79
3.4 Examples for calculation......Page 92
4.1 Types of short-circuits......Page 96
4.2 Methods of calculation......Page 97
4.3 Calculation of parameters of short-circuit currents......Page 99
4.4 Influence of motors......Page 113
4.5 Minimal short-circuit currents......Page 114
4.6 Examples......Page 115
5.1 General......Page 126
5.2 Power system with low-impedance earthing......Page 127
5.3 Power system having earthing with current limitation......Page 131
5.4 Power system with isolated neutral......Page 134
5.5 Power system with resonance earthing (Petersen-coil)......Page 137
5.6 Handling of neutrals on HV-side and LV-side oftrans formers......Page 145
5.7 Examples......Page 148
6.2 Types of faults......Page 160
6.4 Calculation of short-circuit parameters......Page 161
6.5 Minimal short-circuit currents......Page 163
6.6 Examples......Page 164
7.2 Short-circuit currents during double earth-faults......Page 168
7.3 Short-circuit currents through earth......Page 172
7.4 Examples......Page 175
8.1 General......Page 180
8.2 Correction using %/MVA- or p.u.-system......Page 181
8.3 Impedance correction factors......Page 183
8.4 Factor κ for peak short-circuit current......Page 185
8.5 Factor μ for symmetrical short-circuit breaking current......Page 187
8.6 Factor λ for steady-state short-circuit current......Page 189
8.7 Factor q for short-circuit breaking current of asynchronous motors......Page 191
9.1 General......Page 194
9.2 Short-circuit currents from capacitors......Page 198
9.3 Short-circuit currents from batteries......Page 199
9.4 Short-circuit currents from rectifiers......Page 201
9.5 Short-circuit currents from d.c. motors with independent excitation......Page 203
9.6 Total short-circuit current......Page 207
9.7 Example......Page 211
10.2 a.c. systems......Page 224
10.3 d.c. auxiliary installations......Page 238
10.4 Calculation examples (a.c. system)......Page 245
10.5 Calculation examples (d.c. system)......Page 247
11.1 General......Page 254
11.2 Measures......Page 255
11.3 Structures of power systems......Page 269
12.1 Interference of pipelines......Page 274
12.2 Considerations on earthing......Page 286
12.3 Examples......Page 291
13.1 Three-phase a.c. equipment......Page 296
13.2 d.c. equipment......Page 310
Symbols, superscripts and subscripts......Page 316
References......Page 322
Index......Page 328
