Protection Application Handbook

Content......Page 4
General......Page 5
Power Load at No Load, I2 =0......Page 7
Power Line at Load......Page 8
Voltage Drop and Losses in Power Systems......Page 9
Voltage, Reactive and Active Power known at the Recieving End......Page 10
Voltage, Reactive and Active Power known at the Sending End......Page 11
Representation of Long Power Lines......Page 12
One Generator Feeding A Strong Network......Page 14
Equal Area Criteria for Stability......Page 15
Actions to Improve the Stability......Page 18
Shunt Reactors......Page 19
Reactors for Extinction of Secondary Arc at Auto-Reclosing......Page 20
Introduction......Page 23
Factors affecting the Fault Calculation......Page 24
Time Aspect......Page 25
Type of Fault......Page 26
Balanced Fault Calculation......Page 27
Step by Step Instructions - Short Circuit Calculations......Page 28
Short Circuit calculations with short circuit Power......Page 32
Symmetrical Components......Page 36
What is System Earthing......Page 51
Fix the Network to Earth Potential......Page 52
Reduce the Fault Current at Earth Fault......Page 53
Reduce Overvoltages......Page 54
Simplify Location Earth Faults......Page 56
Avoid Ferro-Resonance......Page 57
Direct Earthing......Page 58
Low Resisitance Earthing......Page 59
High Resistive Earthing......Page 61
Resonance Earthing......Page 62
Z/0 - Connected Earthing Transformer......Page 64
Current Distribution at an Earth Fault with a Z/O Earth Transformer......Page 66
Current Distribution at an Earth Fault in a Transmission Network......Page 67
Individual Earthing in Every Neutral Point of the Power Sources......Page 69
Common Earthing Through a Neutral Busbar......Page 70
Common Earthing Through a Earthing Transformer on the Busbar......Page 71
Voltages Between 25 and 100 KV......Page 73
Voltages Between 1 and 25 KV for Distribution......Page 74
Voltages Under 1 KV......Page 75
Comparison of Different Earthing Principles......Page 77
Parallel Resistors for the Resonance......Page 80
Increased Current Through the Resistor at high resistance earthing......Page 81
The Task of the Protection System......Page 83
Operating Conditions of Power System......Page 84
Requirement on Protection System......Page 87
Choice of Protection Equipment......Page 89
Disturbance Registration and Fault Signalling......Page 96
Introduction......Page 97
Fault Types......Page 98
Special Fault Types......Page 99
Requirements on Line Protection......Page 100
Overcurrent Relays......Page 103
Pilot Wire,Optical Line Differential and Phase Comparison Relays......Page 104
Distance and Directional Impedance Protection......Page 111
Application Problems......Page 130
The Principle of an Auto Reclosing Device......Page 132
General Conditions for Auto Reclosing......Page 133
Blocking......Page 136
Auto Reclose for One-and a half Breaker or Ring Bubar Schemes......Page 137
An Auto Reclosing Scheme......Page 143
Auto Reclosing Sequences......Page 145
Synchro Check Device......Page 147
Delayed Auto Reclosing with Synchro Check......Page 149
High-Speed Auto Reclosing with Synchronism Check......Page 151
Arrangement of Synchro-Check Units for Auto Reclosing......Page 153
Synchro-Check Relay/Function......Page 154
Example of Synchro Check  Function Settings......Page 155
General Design......Page 156
Conditions Leading To Faults......Page 163
Relay Protection......Page 164
Differential Protection of Low Impedance Type......Page 165
Differential Protection for Auto-Transformers......Page 169
Back-up Protection Relays......Page 170
Protection Block Diagram......Page 172
Need for Shunt Reactors......Page 175
Connections in the Substation......Page 176
Synchronous Switching of Shunt Reactor Circuit -Breakers......Page 177
Thyristor(Phase-Angle) Controlled Reactors(TCR)......Page 178
Relay Protection for Direct Earthed SR:S......Page 180
Relay Setting......Page 181
Current Transformer Design......Page 183
Primary Sensitivity......Page 184
General About Capacitor Banks......Page 185
Capacitor Bank Overload Relay......Page 186
Short-Circuit Protection......Page 188
Types of Busbar Protection......Page 189
Principles of Differential Busbar Configurations......Page 190
Switching in Current Circuits......Page 194
Protection of MV Busbars in Distribution Networks......Page 195
Application of Busbar Protection......Page 196
Breaker Failure Relays......Page 198
Pole Discordance Relays......Page 200
Fault Resistance and Fault Current Levels......Page 203
Neutral Point Voltages......Page 205
Restricted Earth Fault Protection......Page 206
Logarithmic inverse relay......Page 209
Directional Comparison Schemes......Page 211
Inrush Current Stabilization......Page 214
Z-0 Earthing Transformer......Page 215
Fault Resistance and Fault Current Levels......Page 216
Restricted Earth Fault Protection......Page 217
Earth Fault Protection......Page 219
Fault Resistance and Fault Current Levels......Page 220
Neutral Point Voltages......Page 221
Directional Earth Fault Protection......Page 222
Resonance Earthed Systems......Page 223
Directional Earth Fault Protection......Page 226
Transient Measuring Relays......Page 228
Measuring Earth Fault Current......Page 229
Calculation of Efficiency Factor......Page 232
Current Transformers......Page 235
Current Transformer Output......Page 239
Selection of CT Cores......Page 246
Voltage Transformers......Page 249
Measuring Error......Page 251
Voltage Transformers with several secondary windings......Page 254
Fusing of Secondary Circuits......Page 259
Voltage Transformer Output......Page 257
CT Requirements......Page 263
Overcurrent Protection Relays......Page 264
Impedance and Distance Protection Relays......Page 266
Differential Protection Relays......Page 267
Fault Locators......Page 271
Breaker Failure Relay Type Raica......Page 273
Control System Structure......Page 275
Instrument Transformers......Page 277
Protection and Control Equipment......Page 288
Signalling......Page 293
Interlocking......Page 295
Terminal Numbering System......Page 297
Setting of Protection......Page 301
Protection Relays Setting......Page 304
Relative Selective Protection Relays......Page 315
Selectivity Plan......Page 327
Sub-Divided Protection Systems......Page 341
Arrangement of Trip Circuits......Page 347
Cabling......Page 349
Alarming and Testing......Page 350