IEEE-Generator-Protection

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1

1 Generator Management Relay

Generator Management Relay

Protection, m

etering, and

monitori

ng functions

for generators

..

Presented by:

John Levine

, P

.E.

Levine Lectronics and Lectric, Inc.

[email protected]

770 565-1556

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O

_utline

O

_verview

Theory

Wiring

Security

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2 2

O

_utline

O

_verview

Theory

Wiring

Security

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Generator Protection Generator Protection

What a Generator looks like

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6 Why Upgrade? Generator and Transformer

Existing generator and transformer protection (more than 5 years or

non-digital) may:

± Cause protection security issues

Tripping on through-faults, external faults, swings, load encroachment and energizing

± May lack comprehensive monitoring and communications capabilities

Not provide valuable forensic info that can lead to rapid restoration

± Not be up to ANSI/IEEE Standards!

± Insurance, Asset Reliability and Personal Liabilit y Issues

C37-10 2_{: Guide for the Protection of Synchronous Generators}

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Product

O

_verview

Ideal Protection for Induction and

Synchronous Generators at 2_{5, 50 and 60Hz}

Complete Generator Protection including: Generator Stator Differential

2 _{or 3 Zone Distance Backup}

100% Stator Ground

High speed sampling, 1 2 _{samples per cycle}

Drawout Case Installation

Powerful Fault Recording: Waveform, Sequence of Events

Ethernet and Serial Communications

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Show Generator Theory General

O

_{verview and}

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10 Generator Protection

Internal and External Short Circuits

The

"Wild"

w

e

_r

Syst

em Exciter

St t r

r u d

St t r

ha

_s

e

Syst

em G

_{r u d}

Syst

em Pha

_s

e

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Generator Protection Review

± Abnormal

O

_{perating Conditions}

Loss of Synchronism Abnormal Frequency O_{verexcitation} Field Loss Inadvertent Energizing Breaker Failure

Loss of Prime Mover Power Blown VT Fuses

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1

2

Generator Protection

Abnormal

O

_{perating Conditions}

The

"Wild"

Power

System

G

Exciter Loss of Fi l Loss of Fi l Ov x i ion Ov x i ion Ov x i ion Op n Ci i s Loss of Synchronism Inadv rtent Energizing, Pole Flashover Abnormal Frequency Abnormal Frequency Breaker Failure Reverse Power Over Power

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IEEE

_{PSRC Survey}

± Conducted in early ¶90s, showed many areas of protection lacking ± Unwillingness to upgrade:

Lack of expertise

± To recognize deficiency ± To perform the work

³Generators don¶t trip´ (wrong)

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4

AN

_S

I/IEEE

_Standards

Latest developments reflected in:

± Std.

242

_{: Buff Book}

± C37.10

2

_{: IEEE Guide for Generator Protection}

± C37.101: IEEE Guide for AC Generator Ground Protection

± C37.106: IEEE Guide for Abnormal Frequency Protection

for Power Generating Plants

Th_{ese are created/maintained by t}h_{e IEEE PSRC & IAS} Th_{ey are updated every 5 years}

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Small Machine Protection

IEEE

_{Buff Book}

32 Reverse Power 40 Loss of Ex_citation

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16 Small Machine Protection

IEEE

_{Buff Book}

Medium ± up to 1

2

_{.5 MW}

46N_{egative Sequence}

51V voltage restraint 51G Ground overcurrent 87 Differential

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Small Machine Protection

IEEE

_{Buff Book}

46N_{egative Sequence}

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8

Unit Connected,

High Z

Grounded

Large Machine Protection

IEEE

_C37.102

46N_{egative Sequence} 49 Thermal Overload 51V voltage restraint 51G Ground overcurrent 64 Ground Relay 87 Differential

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2

₀

Protection F nctions

Protection F nctions Incl e:

Generator tator Differential Back Distance Protection 100% tator Gro n

Generator Unbalance Loss of E citation

Acci ental Energi ation Breaker Fail

Phase erc rrent ± Voltage Restraint Ne tral Inst. / T_ime _{erc rrent}

Neg. eq ence erc rrent Un er / er Voltage

Un er / er Freq enc Generator T_{hermal Mo el}

R T_D T_{em erat re}

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Generator Protection with GSU Wrap

PTs on Low Side

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Generator Protection with GSU Wrap

PTs on High Side

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Generator Protection

PTs on Low Side

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Desirable

A

_{ttributes - Generator}

± Reverse Power (32₎

Should be sensitive to 0.05 pu to properly detect motoring in large steam turbines

± Existing E/M and Static relays not sensitive enough ± May cause shutdown difficulties

± Negative Sequence (4₆₎

Should be sensitive to low values to detect open poles/conductors on system after GSU

± Existing E/M and Static relays not sensitive enough

Long time low level events may cause excessive rotor heating, thermal tripping and damage rotor

± 100% Stator Ground (59N / 59D)

Protects all of the stator winding

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2

₆

Desirable

A

_{ttributes - Generator}

Inadvertent Energizing (50/

2

₇₎

± High speed tripping of unit after breaker accidentally closed on dead machine, also pole flashover prior to syncing

Most existing schemes do not incorporate

± Many schemes fail due to complexity (reliance on breaker auxiliary switches, yard distance relays, etc.

± If breaker is not tripped rapidly, mechanical and electric damage can occur to machine in fractions of a second!

± Pole flashovers must be cleared by high speed breaker failure, as the breaker is open!

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Protection F nctions

Generator tator Differential

tator Phase Differential

D al lo e Percent Restraint erating Characteristic

Directional er ision n er sat ration con itions

Distance Back

Protection

2 or 3 Zone Mho Distance Protection Back for rimar line rotection

Config rable Reach an Angle Distance Characteristic

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Protection F nctions

T

_{hermal Protection}

Generator T_{hermal Mo el}

R T_{D Alarming an} T_{ri ing}

R T_{D Biase} T_{hermal Mo el}

Ina ertent Energi ation

Pre ents Acci entall Closing a to e Generator onto a Li e Line

Arme w_{hen Generator is ffline an Voltage is}

below _{a re-set le el}

Loss of E citation

(show T_{raining CD)}

Uses Im e ance Circle for loss of e citation etection

2 Zones for fa lt etection an control

T_{hermal Mo el ± Voltage}

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3

8

S

_{ec rit A it}

T

_rail

Date an time of har w_are,

firmw_{are or setting changes to}

o r rela s

Logging of the MAC a ress of com ters an sers making settings changes

T_{rack metho of ho}w _settings

changes w_{ere ma e (i.e. ke a ,}

serial ort, ethernet)

S

_{ec rit strateg ± conforms to in str an reg late g i elines}

Date/time sec rit re ort

w_{as generate}

Descri tion of the GE M ltilin Rela

Su_{mmar of the}

last time the configu_ration w_{as change}

Histor of last 10 occu_{rrences the}

configu_ration w_{as change}