POWER SYSTEM ANALYSIS SECOND EDITION (original) (raw)
Abnormal conditions other than short circuits,, 8 A-c tripping, 335 Angle-impedance relay, 79 for tripping on 1088 of synchronism, 362 Angle of maximum torque, adjustment,, 57 of power relays, 52, 55 of shortcircuit relays, 55 Arcs, effect on distance relays, 345 resistance, 302 Arc -furnace -transformer protection, 270 ASA accuracy classification,, of current transformers,, 121 of potential transformers, 133 Attenuation, carrier-current, 378 Automatic reclosing, see Reclosing, automatic Auxiliaries,, station, protection of, 229 see also Motor protection Back-up relaying, defined, 6 effect of intermediate current sources, 347 for bus protection, 275, 291 generator external fault,227 reversed third zone, 175, 349 transformer external fault, 264, 268 with pilot relaying, 378, 386 Blind spot in pilot relaying, 94 Blinder with directional-comparison relaying, 386, 390 Blocking pilot, 88, 91 Blocking terminal, with a-c wire-pilot relaying, 375 I N D E X Capacitance potential device, equivalent circuit, 135 non-linear burdens, 139 standard accuracy, 137 standard rated burdens, 136 Capacitor, series, effect on distance relaying, 367 Capacitor tripping, 335 Carrier-current attenuation, 378 Carrier-current-pilot relaying, see Pilot relaying, carrier-current Circuit breaker, by-passing, 292 standard capacities, 3 Circulating-current pilot relaying, 92, 94 Cold-load pickup, 334 Cold-load restoration, 334 Compensated voltage, see Transformer compensation Constant-product characteristic, 38 Contact definitions, 17 Contact races in pilot relaying, 91 Continuous pilot, 109 Control spring, 17 Conventions, vector, 53 Corrosion, effect of polarity on, 19 Coupling-capacitor description, 134 Coupling-capacitor insulation coordination, 142 Coupling-capacitor potential device, Bee Capacitance potential device Current-balance relay, directional type, 62 for line protection, 330 overcurrent type, 58 Current biasing, for mho relay, 82 for offset impedance relay, 77 to avoid distance-relay misoperation on arcs, 346 Current compensation for ground distance relays,, 360 Current switching for distance relays, 368 Current transformers,, accuracy calcula , 113 ASA accuracy classification, 121 burden, 114 for generator differential relaying, 198 ratiocorrection-factor curves,, 116 secondaryexcitation curves,, 117 grounding the secondaries of differentially connected CT's, 291 overvoltage in secondary, 124 polarity and connections, 126 proximity effect, 126 Current transformers, requirements for pilot relaying, 377 secondary leakage reactance, 117, 119, 120 transient errors, 124, 278, 318 types, 113 zero-phase-sequencecurrent shunt, -130, 249 D-c offset, effect on induction relays, 32, 39 overreach of distance relays, 82, 350 overreach of overcurrent relays, 308 time constant, 279 D-c relays, single-quantity, 22 directional, 24, 49 Differential relays, 63 see also Percentagedifferential relays Directional-comparison relaying, for bus protection, 277 principle of operation, 106 see also Line protection with pilot relays Directional control, of electromagnetic relays,, 23 of single-quantity induction relays,, 32,57,310,313 Directional-overcurrent relay, 57 Directional relays,, a-c types, 33, 52 connections,, 52 power, 52 short circuits, 56 characteristics on R-X diagram, 74 d-c types,, 49 use of shunts, 52 effect of mutual induction on ground relays, 393 electromagnetic-attraction type, 24 groundrelay polarization, 151, 326 misoperating tendencies, 314 negative-phase-aequence type, 330 operating characteristics,, 37 response of polyphase relays to positive and negative phase sequence,, 183 response of ainglephase relays to short circuits,, 187 Distance relays,, current and voltage switching, 368 effect of power swings and lose of synchronism,, 181 effect of wye-delta transformer between relay and fault, 172 electronic type, 369 ground-relay connections, 360 impedance seen during faults,, 167 Generator protection, overvoltage, 217 potential-transformer fuse blowing, 228 prime mover, 230 station auxiliary, 229 stator overheating, 216 stator short circuit, 195 calculation of CT errors, 198 ground faults, sensitive, 208 ground faults in unit generators, 209 overcurrent relays for, 215 turn-to-turn faults, 204 unbalanced phase currents, 221 vibration, 225 Ground-distance-relay connections, 360 Ground-fault neutralizer, effect on line relaying, 321 to mitigate the effect of a fault, 2 Grounding protective relay for trans former protection, 263 Ground preference, 91, 108 Ground resistance, 303 Grounding-tranaformer protection, 268 Hsrmonic-current restraint, for distance relays,, 357 for transformer differential relays, 257 Holding coil, 18 Impedance diagram, see R-X diagram Impedance relay, characteristic on R-X diagram, 72 for line protection, 340 general, 70 see also Distance relays Induction-cup and induction-loop structures, 30, 31 Induction-type relay, directional, 31 general characteristics,, 26 single-quantity, 31 structures, 29 torque production, 26 Insulating transformer for pilot-wire circuits,, 98 Intermittent pilot, 109 Line protection with distance relays,, adjustment of distance relays,, 341 area, effect of, 345 blocking tripping on 1088 of synchro , 304 choice between impedance, reactance, and mho,, 340 connections of ground distance relays,, 360 Distance relays,, use of low-tension voltage, 145, 148 see also Line protection with distance relays Distribution-circuit protection, see Line protection with overcurrent relays Drop-out defined, 17 Electric arc-furnace-transformer protection, 270 Electromagnetic-attraction relay, directional, 24 general characteristics,, 16 single-quantity, 22 Electronic relay, directionalcomparison pilot, 396 distance, 369 I N D E X Evaluation of protective relaying, 12 Expulsion protective gaps, effect of, on distance relays, 367 External-fault back-up relaying, see Back-up relaying Fail ures,, electrical, see Faults False residual current, 318 Fault bus, 275 Faults, mitigation of effects of, 2 prevention of, 2 probability of, effect on practice, 11 see also Short circuits Fire, protection against, 230 Fire-pump-motor protection, 230 Footing resistance, tower-, 303 Frequency, compensation of relays for changes in, 49 effect on induction relays,, 32, 39 Frequency-converter protection, see Generator protection Fundamental principles of protective relaying, 4 Fuse, coordinating with a, 335 Fuse blowing, potential-tranaformer, effect on distance relays,, 361 effect on generator relays,, 228 Generator protection, bearing overheating, 228 external-fault back-up, m field ground, 218 loss of excitation, 223 1088 of synchronism,, 218 miscellaneous,, 228 motoring, 225 open circuits,, 215 over excitation,, 225 over speed,, 226 Line protection with distance relays, current and voltage switching, 368 expulsion protective gaps, effect of, 367 fuse blowing, effect of, 361 electronic relays, 369 intermediate current sources, effect of, 347 low-tension current, use of, 356 low-tension voltage, use of, 352 magnetizing inrush, effect of, 359 overreach, 351, 360 purposeful tripping on loss of synchronism, 361 reclosing, automatic, 366 series capacitor, effect of, 367 see also Distance relays Line protection with overcurrent relays, a-c and capacitor tripping, 335 adjustment of ground vs. phase re lays, 316 adjustment of inverse-time-overcur rent relays, 297 arc and ground resistance, 302 directional feature, 310 fuses, coordination with, 335 ground faults in ungrounded systems, detection of, 319 ground-fault neutralizers, effect of, 321 instantaneous overcurrent relays,, use of, 306 inverseness,, choice of, in relay char acteristics, 305 limiting ground-fault-current magni tude, effect of, 317 loop circuits,, effect on relay adjust , 303 misoperation prevention of aingle directional-overcurrent re during ground faults, 314 negative-phase sequence ground di Line trap, 100 Linear couplers, 284 Load shedding, 334, 363 Locking in, with generator differential relaying, 202 with transformer differential relaying, 251 Loss-of-excitation protection, 223 Loss-of-field protection, 223 Loss of synchronism, characteristics on RX diagram, 177 derivation of relay current and voltage, 176 effect on distance relays, 181 generator protection, 218 trip-blocking relay, 304, 390 tripping relay, 361 Low-tension current for distance relays, 356 Low-tension voltage, for directional relaying, 386 for distance relaying, 148, 352 general, 145 Magetizing-current inrush, effect on distance relays, 359 effect on transformer differential relays, 254 in parallel transformer banks, 259 Maximum torque, angle of, adjustment, 57 power relays, 52, 55 short-circuit relays, 55 Memory action, described, 83 effect of voltage source location, 144 Mho relay, characteristics on R-X diagram, 81 for line protection, 340 operating characteristic, 80 Microwave-pilot relaying, see Pilot relaying, microwave Minimum pickup of directional relays,, 38 Mixing transformer for wire-pilot relaying, 96 I N D E X Modified-impendance relay, 77 Motor protection, field ground, 237 fire-pump, 230 1088 of excitation, 237 1088 of synchronism, 236 rotor overheating, 236 stator overheating, 232 stator short circuit, 230 unattended motors,, 230 under voltage,, 237 Multiterminal-line protection, with a-c wire-pilot relaying, 376 with directional-comparieon pilot relaying, 387 with phasecomparison pilot relaying, 382 Mutual induction, effect of, on direc relays,, 393 from power circuit to pilot wires,, 88 Neutralizing transformers for wire-pilot circuits,, 99 Normally blocked trip circuit, 109 Open phase, effect of, on directional relays, 323, 325 equivalent circuits for, 323 protection of generators against, 215 Operating principles,, basic, electromagneticattraction relays,, 16 Operating principles, directional type, 24 singlequantity type, 22 induction relays: directional type, 33 singlequantity type, 31 Operation indicator, 17 Operator vs. protective relays, 11 Opposed-voltage pilot...
01_02_37_2018.pdf_ Mathematical Model of Electrical Line with Transposition of Phase.pdf
The purpose of this paper is to elaborate the mathematical model and the method of calculation of the permanent regime in the line with many conductors with transposed phases. The mathematical model is based on the telegraph equations and takes into account the fact that the electric lines are lines with distributed parameters. As a subject of the study it is selected the 110 kV overhead power line with two compact circuits with the conductors placed horizontally and circularly transposed. The initial and boundary conditions are formulated for the case of two-circuit electric line and the adjustment of the phase angle of the voltages at the line input. In the transposition the values of the conductor parameters change by leap, which complicates the process of calculating the operating mode. The developed model and elaborated software include all these features. Based on the developed model, calculations of the operating mode of the two-circuit electric circuit and of the selfcompensated line were performed. Numerical solutions have been obtained regarding the evolution of active and reactive power in the phases of the line in its various sections under regulation and nonregulation of the phase shift angle for the cases without and with the transposition of the phase conductors. The applicability of the model for studying power transfer processes in multi-conductor power lines has been demonstrated. There were obtained the numerical solutions useful for estimating the degree of mutual influence of phases on the ability to transfer power to load under the transposition of conductors.