The Art & Science Of Protective Relaying – C. Russell Manson – 1st Edition

Abnormal conditions other than short circuits

A-c tripping

Angle-impedance relay

for tripping on 1088 of synchronism

Angle of maximum torque, adjustment

of power relays

of shortcircuit relays

Arcs, effect on distance relays, 345 resistance

Arc - furnace - transformer protection

ASA accuracy classification,, of current transformers

of potential transformers

Attenuation, carrier-current

Automatic reclosing, see Reclosing,automatic

Auxiliaries,, station, protection of

see also Motor protection Back-up relaying, defined,

effect of intermediate current sources,

for bus protection

generator external fault

reversed third zone

transformer external fault

with pilot relaying

Blind spot in pilot relaying

Blinder with directional-comparison relaying

Blocking pilot

Blocking terminal, with a-c wire-pilot relaying,

with directionalcomparison pilot relaying,

with phase-comparison pilot relaying,

Broken-delta connection, burden calculation,

for detecting grounds in ungrounded systems

for polarizing directionalground relays

of capacitance potential devices

Buchholz relay

Burden, current-transformer,

potentialtransformer,

Bus protection

automatic reclosing

back-up relays

circuitbreaker by-psasing

combined power transformer and bus,

current differential with overcurrent relays,

current differential with overvoltagerelays,

current differential withpercentage relays,

directional comparison,

fault bus

grounding

secondaries of differentially connected CT's,

partial-differential,

ring-bus,

testing,

voltage differential with linear cou

Bushing potential device,

see Capacitance potential device

Capacitance potential device

broken burden

comparison with instrument PT's,

couplingcapacitor insulation coordination,

effect of overloading

Capacitance potential device, equivalentcircuit,

non-linear burdens,

standard accuracy,

standard rated burdens,

Capacitor, series, effect on distance relaying,

Capacitor tripping,

Carrier-current attenuation,

Carrier-current-pilot relaying, see Pilot relaying,

carrier-current

Circuit breaker, by-passing,

standard capacities,

Circulating-current pilot relaying,

Cold-load pickup,

Cold-load restoration,

Compensated voltage,

see Transformer

compensation

Constant-product characteristic,

Contact definitions,

Contact races in pilot relaying,

Continuous pilot,

Control spring,

Conventions, vector,

Corrosion, effect of polarity on

Coupling-capacitor description,

Coupling-capacitor insulation coordination,

Coupling-capacitor potential device, Bee Capacitance potential device

Current-balance relay, directional type,

for line protection,

overcurrent type,

Current biasing, for mho relay,

for offset impedance relay,

to avoid distance-relay misoperation on arcs,

Current compensation for ground distance relays

Current switching for distance relays

Current transformers,

accuracy calcula

ASA accuracy classification, burden,

for generator differential relaying,

ratiocorrection-factor curves

secondaryexcitation curves

grounding the

secondaries of differentially connected CT's,

overvoltage in secondary,

polarity and connections,

proximity effect,

Current transformers, requirements for pilot relaying, 377 secondary leakage reactance,

transient errors,

types,zero-phase-sequencecurrent shunt

D-c offset, effect on induction relays,

overreach of distance relays,

overreach of overcurrent relays,

time constant,

D-c relays, single-quantity,

directional,

Differential relays,

see alsoPercentagedifferential relays

Directional-comparison relaying,

for bus protection,

principle of operation,

see also Line protection with pilot relays

Directional control, of electromagnetic relays

of single-quantity induction relay

Directional-overcurrent relay

Directional relays,, a-c types

connections,,

power,

short circuits,

characteristics on R-X diagram,

d-c types,,

use of shunts,

effect of mutual

induction on ground relays,

electromagnetic-attraction type,

groundrelay polarization,

misoperating

tendencies,

negative-phase-aequence

type, 330 operating characteristics,

response of polyphase relays to positive and negative phase sequence,,

response ofainglephase relays to short circuits

Distance relays,, current and voltage switching,

effect of power swings and lose of

synchronism,, effect of wye-deltatransformer between relay and fault,

electronic type, ground-relay connections,

impedance seen during faults,,

Generator protection, overvoltage,

potential-transformer fuse blowing,

prime mover,

station auxiliary,

stator overheating,

stator short circuit,

calculation of CT errors,

ground faults,

sensitive,

ground faults in unit generators,

overcurrent relays for,

turn-to-turn faults,

unbalanced phase currents,

vibration,

Ground-distance-relay connections,

Ground-fault neutralizer, effect on line relaying,

to mitigate the effect of a fault,

Grounding protective relay for trans forme rprotection,

Ground preference,

Ground resistance,

Grounding-tranaformer protection,

Hsrmonic-current restraint, for distance relays,,

for transformer differential relays,

Holding coil,

Impedance diagram, see R-X diagram Impedance relay, characteristic on R-X

diagram, for line protection, general, see also Distance relays Induction-cup and induction-loop structures,

Induction-type relay, directional, generalcharacteristics,,

single-quantity, structures, torque production, Insulating transformer for pilot-wire circuits,,

Intermittent pilot,

Line protection with distance relays adjustment of distance relays area, effectof, blocking tripping on of

synchro , choice between impedance, reactance, and mho,, connections of ground distance relays,,Distance relays,, use of low-tension voltage

see also Line protection with distance relaysDistribution-circuit protection, see Lineprotection with overcurrent relays

Drop-out defined, Electric arc-furnace-transformer protection,

Electromagnetic-attraction relay, directional,

general characteristics,, single-quantity,

Electronic relay, directionalcomparison pilot,

Evaluation of protective relaying,

Expulsion protective gaps, effect of, on distance relays,

External-fault back-up relaying, see Back-up relaying

Fail ures,, electrical, see Faults

False residual current,

Fault bus,

Faults, mitigation of effects of, prevention of,

probability of, effect on practice, 11 see also Short circuits

Fire, protection against,

Fire-pump-motor protection,

Footing resistance, tower-,

Frequency, compensation of relays for changes

in, effect on induction relays

Frequency-converter protection, see Generator

protection

Fundamental principles of protective relaying,

Fuse, coordinating with a,

Fuse blowing, potential-tranaformer, effect on distance relays

effect on generator relays

Generator protection, bearing overheating,

external-fault back-up, m field ground,

loss of excitation,

of synchronism,, miscellaneous,

motoring,

open circuits,, 215 over excitation,, over speed,,

Line protection with distance relays, current

and voltage switching, expulsion protective gaps, effect of, fuse blowing,

effect of, electronic relays,

intermediate current sources, effect of,

low-tension current, use of, low-tension

voltage, use of, magnetizing inrush, effect

of, overreach, purposeful

tripping on loss of synchronism,

reclosing, automatic, series capacitor,

effect of, 367 see also Distance relays

Line protection with overcurrent relays,

a-c and capacitor tripping,

adjustment of ground vs. phase re lays,

adjustment of inverse-time-overcur

rent relays,

arc and ground resistance,

directional feature,

fuses, coordination with,

ground faults in ungrounded systems,

detection of,

ground-fault neutralizers, effect of,

instantaneous overcurrent relays,, use of,

inverseness,, choice of, in relay char acteristics,

limiting ground-fault-current magni tude, effect of,

loop circuits,, effect on relay adjust

misoperation prevention of aingle

directional-overcurrent re during ground faults,

negative-phase sequence ground di rectional relays,,

open phases, effect of,

overreach of instantaneous overcur

rent relays,,

polarizing ground-relay directional

unite,

reclosing, automatic,

restoration of service after prolonged outage,

single-phase vs. polyphase directional relays,,

transient CT errors,

two vs. three relays for phase-fault protection,

Line protection with overcurrent relays, see also

Overcurrent relays

Line protection with pilot relays, a-c

wire-pilot relaying,

back-up protection,

CT requirements,

multi terminal lines,

sensitivity,

see also Pilot relaying, a-c wire-;

Pilot relaying, d-c wire relaying, attenu ation,

sleet detection,

supervision, automatic,

combined phase- and directional com

parison, mutual induction, effect on ground relays,

when to use,

directional comparison, electronic,

low-tension voltage, use of,

multi terminal lines,

sensitivity,

transients,, effect of,

when to use,

see also Pilot relaying, carrier-cur ,

phase comparison, back-up protection,

multi terminal lines,

sensitivity,

when to use,

see also Pilot relaying, carrier-cur

rectional relays,,

open phases, effect of,

overreach of instantaneous overcur

rent relays,,

polarizing ground-relay directional

unite,

reclosing, automatic,

restoration of service after prolonged

outage,

single-phase vs. polyphase directional

relays,,

transient CT errors,

two vs. three relays for phase-fault

protection,

Line protection with overcurrent relays, see also

Overcurrent relays

Line protection with pilot relays, a-c

wire-pilot relaying,

back-up protection,

CT requirements,

multi terminal lines,

sensitivity,

see also Pilot relaying, a-c wire-;

Pilot relaying, d-c wire relaying, attenuation,

sleet detection,

supervision, automatic,

combined phase- and directional com

parison, mutual induction, effect

on ground relays,

when to use,

directional comparison, electronic,

low-tension voltage, use of,

multi terminal lines,

sensitivity,

transients,, effect of,

when to use,

see also Pilot relaying, carrier-cur ,

phase comparison, back-up protection,

multi terminal lines,

sensitivity,

when to use,

see also Pilot relaying, carrier-current

reclosing, high-apeed,,

when to use pilot relaying,

Line trap,

Linear couplers,

Load shedding,

Locking in, with generator differential relaying,

with transformer differential relaying,

Loss-of-excitation protection,

Loss-of-field protection,

Loss of synchronism, characteristics on RX

diagram, derivation of relay current and

voltage, effect on distance relays,

generator protection, trip-blocking relay,tripping relay,

Low-tension current for distance relays,

Low-tension voltage, for directional relaying,

for distance relaying, general,

Magetizing-current inrush, effect on distance

relays, effect on transformer differential

relays, in parallel transformer banks,

Maximum torque, angle of, adjustment,

power relays, short-circuit relays, 55

Memory action, described, effect of voltage

source location,

Mho relay, characteristics on R-X diagram,

for line protection, operating

characteristic,

Microwave-pilot relaying, see Pilot relaying,

microwave

Minimum pickup of directional relays

Mixing transformer for wire-pilot relaying,

Modified-impendance rela

Motor protection, field ground, fire-pump,

of excitation, of

synchronism, rotor overheating,

stator overheating, stator short circuit,

unattended motors, under voltage,,

Multiterminal-line protection, with a-c wire-pilot

relaying, with directional-comparieon

pilot relaying, with phasecomparison

pilot relaying,

Mutual induction, effect of, on direc relays,,

393 from power circuit to pilot wires,, 88

Neutralizing transformers for wire-pilot circuits,,

Normally blocked trip circuit,

Open phase, effect of, on directional relays,

equivalent circuits for,

protection of generators against,

Operating principles,, basic, electromagneticattraction relays,,

Operating principles, directional type, singlequantity type, induction relays: directional

type, singlequantity type,

Operation indicator,

Operator vs. protective relays,

Opposed-voltage pilot relaying,

Out of step, see Loss of synchronism

Overcurrent relays, combination of

instantaneous and time delay, pickup or

reset, time delay see also Line

protection with overcurrent relays

Overreach, of distance relays, of

instantaneous overcurrent relays,

Over travel,, defined, effect of, on

overcurrent-relay adjustment,

Overvoltage, in CI secondaries, see also

Generator protection

Overvoltage relays, pickup or reset,, time

delay,

Percentage-differential relays, description, for

bus protection, for generator protection,

for transformer protection, locking-in

for internal faults product restraint,

variable percent slope,

Petersen coil, see Ground-fault neutralizer

Phase-comparison relaying, principle of

operation, see also Line protection with

pilot relays

Pilot relaying, circulating current,

general, line protection, opposed

voltage, pilot-wire protection, pilotwire requirements,

pilot-wire supervision,

remote tripping, see also Line

protection with pilot relays

Pilot relaying, carrier-current-, directional

comparison, general, intermittent or

continuous, phase comparison, pilot

described, supervision of pilot channel,

see also Line protection with pilot relays ;

Pilot relaying,-d-c wire-, basic principles,

description of pilot

Pilot relaying, micro-wave-, description of

channel, general, remote

tripping, see also Line protection with

pilot relays

Pilot relaying, principles of, ground preference,

purpose of a pilot, sensitivity levels,

tripping and blocking pilots,

Polarizing quantity, of a-c directional relays'

of d-c directional relays, of directional

units of ground relays,

Polyphase directional relays, advantages and

disadvantages, response to positive- and

negative volt-amps

Potential device, see Capacitance potential

device

Potential transformers, accuracy,

connections, effect of fuse blowing, on

distance relaying, on generator relaying,

low-tension voltage for distance relays,

Power-balance relaying for line protection,

Power-rectifier-transformer protection,

Power swings, see Loss of synchronism

Power transformer and autotransformer

protection, external-fault backup,

gasaccumulator and pressure relays,

grounding protective relay, overcurrent

relaying, percentagedifferential relaying,

CT accuracy requirements, CT

connections, CT ratios, magnetizing

inrush, effect of, parallel banks,

percent slope, choice of, two-winding

relay for threewinding transformer, zerophasesequence-current shunt, remote

tripping,

Primary relaying defined,

Product restraint for generator differential

relays,

Protective relaying, evaluation of, function

of, functional characteristics of,

fundamental principles of,

Ratings, relay, contact, current and voltage,

holding coil, seal-in coil, and target,

Ratio correction factor, see Current

transformers; Voltage trans formers

Reactance relay, characteristic on R-X diagram,

operating characteristic, partialdifferential bus protection, see also Line

protection with distance relays

Reclosing, automatic, affected by remote

tripping, effect on blocking-terminal

pilot equipment, mitigation of fault

effects, of bus breakers,, single-phase

switching, synchronism check

with distance relaying, with overcurrent

relaying, with pilot relaying,

Rectifier-transformer protection,

Regulating-transformer protection, ex fault

back-up, in-phase type, phase-shifting type,

Reliability, a functional relay characteristic,

Remote tripping, by carrier current, by

microwave, by pilot wire, for powertransformer protection, frequency-shift system,

Replica-type relays, for generator protection,

for motor protection,

Reset, adjustment of, defined, ratio to

pickup, electromagnetic relays, induction

relays, time of induction relays,

Reversed third zone, for back-up with carrier

pilot, where a line includes a

transformer,

R-X diagram, los-of-synchronism char ,

appearance to distance relays principle

of, short-circuit characteristics,

appearance to distance relays wyedelta

transformer between relay and fault

superposition of relay and system

characteristics,

Seal-in coil or relay,

Secondary excitation curves,,

Selectivity, a functional relay characteristic,

Sensitivity, a functional relay char , levels of

blocking and tripping for pilot relaying

Shaded-pole structure,

Short circuits, derivation of relay current and

voltage, impedance seen by distance

relays,, table of currents,, 164 table of

voltages,, see also Faults

Single-phase switching,

Sleet-accumulation detection with carrier

current,

Speed, a functional relay

characteristic,,

Split-phase relaying, combined with percentage

differential,

for generators,

Stability, system, benefited by protective relaying,

Step-voltage-regulator protection,

Supervision, automatic, of carrier channel,

of pilot-wire circuits,

Synchronism check with automatic reclosing,

Target,

Telephone-circuit restrictions,

Testing, relay, field, manual,

Time characteristics, adjustment of, definitions,,

of d-c directional relays,

of electromagnetic-attraction relays,

of induction relays,

Time constant of d-c component,

Torque control, see Directional control

Torque production in induction relays,

Tower-footing resistance,

Transferred tripping, see Remote tripping

Transformer-drop compensation, fordirectional-comparison pilot relaying,

for distance relaying,

Transformer protection, see: Electric

arcfurnace-transformer protection;

Grounding-transformer protection; Powerrectifiertransformer protection;

Powertransformer and autotransformer

protection; Regulating-trans former

protection; Step-voltage protection

Transients, effect of, on directional pilot relaying,

on distance relaying,

on electromagnetic-attraction relays,

on overcurrent relays,

Transient blocking,

Transient shunt, for distance relays,

for overcurrent relays,

Transmission-line protection, with distance relaying,

with overcurrent relaying,

Tranemission-line protection, with pilot relaying,

Trap, line,

Tripping pilot,

Tripping suppressor for transformer differential relays,

Tripping, undesired, vs. failure to trip,

Undercurrent and under voltage relays, pickup or reset,

Universal relay torque equation,

Variable restraint for generator differential relays,

Vector conventions,

Vibration, of electromagnetic-attrao relays,

protection for generators,

Voltage-balance relays,

Voltage compensation for ground distance relays,

Voltage-regulator protection, see also

Regulating-transformer protection; Stepvoltage-regulator protection

Voltage switching for distance relays,

Voltage transformers, see Capacitance potential

devices; Potential transformers

Watthour-meter structure,

Wire-pilot relaying, see Pilot relaying, a-c wire-;

Pilot relaying, d-c wire

Zero-phase-sequence-current shunt, currenttransformer connections, used with

transformer differential relays