1NTG-Slide-03-2008

NTGMULTIFUNCTON GENERATOR PROTECTION RELAY

2NTG-Slide-03-2008

NTGNTGDigital protection relay that integrates a number of functions rDigital protection relay that integrates a number of functions required for the protection of equired for the protection of generators. It is used in power stations from gas, steam, hydrgenerators. It is used in power stations from gas, steam, hydraulic turbine, or diesel aulic turbine, or diesel driven generators, operating in parallel with the public networkdriven generators, operating in parallel with the public network

and/or in island and with and/or in island and with any neutral state and network layout.any neutral state and network layout.

3NTG-Slide-03-2008 Applications

EMERGENCY GENERATORS

100 kVA

… 2 MVA, in BT e MTpowered by diesel motors or small gas turbines

DISPERSED GENERATORS

1 MVA …

10MVA, in MTpowered by diesel motors or small gas turbines, wind, solarIndustial plants

COGENERATION

1 MVA a 50 MVA, in MTCogeneration power plants (Gas&oil, chemical..)

POWER STATION

from 10 MVA to several hundreds MVAPowered by Hidro, Gas, Steam, Gas turbines

4NTG-Slide-03-2008

LCD display

keyboard

1 LED (ON service)+

7 free assignable

LEDs

8 free assignable LEDs

8 free assignable LEDs

(optional)

Power supply LED

RS232 local communication interface

19”

rack (h=3U, p=300 mm)

Front viewM

MI

A

B

C

D

G

H

I

E

DSP and CPU LEDsF

A B C D F G H IE

5NTG-Slide-03-2008

8 binary inputs

RTD inputs (optional)

Current inputs

Power supply

8 output relays

Remote interfaceRS485+RJ45 or Fiber optic (MODBUS TCP/IP)

8 output relays (optional)

8 binary inputs (optional)

Voltage inputs

earth terminal

Rear view

A B L-M NFEC-D

T

G-H

I/O

wit

h c

on

necto

rized

term

inals

A

B

C-D

E

G-H

L-M

N

R

F

TR

6NTG-Slide-03-2008

Rotor earth fault module

8 binary inputs + 8 LEDs

module

PT100 module

Power supply module

CPU module

8 output relays module

Communication module

CT/VT module

DSP module

Layout

A

B

C

D

F

G

H

E

L

D DC

F H

A B

E

GC L

7NTG-Slide-03-2008 Hardware structure

PARALLEL BUS

16 channels 10 bit ADCmeasure&protection(DFT 16 samples/period)

3 phase currents1 residual current3 phase voltages1 residual voltage1 rotor earth fault

thyb

us

control&communication

local (RS232)remote RS485 + Ethernet (F.O./RJ45)

(2Mbyte) (8Mbyte)

MEASURING INPUTS 40MHz DSP

COMMUNICATION INTERFACE

66 MHz CPU FLASH SDRAMSPI

SERIAL

BUS

I/O

MMI

8NTG-Slide-03-2008 Selection table

9NTG-Slide-03-2008 Input/Output

Keyboard

8 LEDs

(optional)

8 output relays (optional)

8 output relays

16 LEDs

3 IL

(hw setting 1A-5A)

IE

(hw setting

1A-5A)

3 UL

(UN

sw programmable)

UE

(UEN

sw

programmable)

8 binary inputs (optional)

8 binary inputs

UAUX

on request:48…110 Vac/dc

24 Vac/dc230 Vac

(DAC200)

8 Inputs PT100 (optional)

64 Earth fault (optional)

RJ45 Ethernet

Port

(optional)

Optical

Ethernet

Port

(optional)

RS485 Port

RS232 port

10NTG-Slide-03-2008 Protection elements

Underimpedance

(21) or voltage-controlled overcurrent

protection

(51V)

coordination with distance protective devices

R

X

Z<<Z<

21-51V

ZZ<< Z<

t

t<<

t<

G 21

ATMT

21

11NTG-Slide-03-2008 Protection elements

a) Generator with step up transformer b) Directly connected generator

G 50-51

51V

MTMT

voltage controlled 51V element

U

G

Underimpedance

(21) or voltage-controlled overcurrent

protection

(51V)

Overcurrent

protections coordination

21-51V

50-51

50-51MT

51V voltage restrained 51V element

U

12NTG-Slide-03-2008

GEN

26 (up to 8 RTD probes)

1 alarm pickup + 1 trip for each probe:

PT100

Stator windings

TR

bearings

rotor

stator

TUR

shaft

q

t

t

U/f

IEC A-B-C

Generator limits

transformer limits

Overflux

V/Hz24 Thermal Protection with RTD’s

probes (PT100)26

Protection elements

13NTG-Slide-03-2008

t

U

t

U

t

I2

Generator limit

I22t=K

Undervoltage27

Overvoltage59

Negative sequence overcurrent46

Protection elements

14NTG-Slide-03-2008

measurement from broken delta VT

No earth faults100%

0%

third harmonicVoltage level

100% 0%

100% 0%

measurement on star point

100% 0%

59N (stator earth fault 90%)

27H-59H70%90%

N

T

G

27H59N

G59N59H

27H –

59H 100% Stator earth fault protection with 3°

harmonic

27H

59H

Earth faults at the star point

Earth faults at the terminals

Protection elements

15NTG-Slide-03-2008

Q

P

32R 37P 32

32 Active directional overpower

32 R Active reverse power

37 P Active underpower

Protection elements

Faults in prime moverSequential tripping logic

Load sheddingNetwork separation

Sequential tripping logic

16NTG-Slide-03-2008

second threshold (delayed)

alarm

R

X

40 Loss of field

Loss of field with low load initial condition

Loss of field with light load initial condition

Loss of field with heavy load initial conditionfirst threshold (fast)A

B

C

A

C

B

Protection elements

17NTG-Slide-03-2008

Earth fault (50G/51G) or restricted earth fault (87N) (90% stator earth fault)

Overcurrent

Neutral overvoltage

(90% stator stator

earth fault)

Rotor earth fault

Inadvertent energization

t

I

IEC A-B-C

I2t=cost

I2t=cost

50/51

50G/51G

87N

59N

64F

50+27

49 Thermal image

Protection elements

18NTG-Slide-03-2008

≥1

&&

&

≥1

&

IL1

≥

I>

IL2

≥

I>

IL3

≥

I>

UL1

≤

U<

UL2

≤

U<

UL3

≤

U<

TRIP 74TV

1. VT at GEN side

2. VT at GRID side

CB OPEN

1

2

t1

t2

TRIP

50+27

Inadvertent energization50+27

Protection elements

19NTG-Slide-03-2008

f

G T

grid

C1 C2 C3 C4

80 MW

40 M

W

30 M

W

10 M

W

50 MW

Q open:C1+C2+C3+C4 (130MW) powered by G (80MW)

Q

Cut load C1 (50 MW)

t

fN

Forbidden area

( turbine demage)

Cut load C2 (40 MW)

Cut load C3 (30 MW)

Cut load C4 (10 MW)

130 MW

81<

81> Overfrequency 81< Underfrequency

50 M

W

Coordination example between four stage pickups

underfrequency

protection and turbine limits (Load Shedding)

Protection elements

20NTG-Slide-03-2008

≥1

&

IL1

≥

I>

IL2

≥

I>

IL3

≥

I>

IE

≥

IE>

CB CLOSED

TRIP INTERNAL PROTECTIONStBF

TRIP EXTERNAL PROTECTIONS≥1

BF BLOCK

NOTA: with CTs

at the line side, the current measures and the CB status make reliable the breaker failure function even if the currents are not present (ie. trip 32R, 24, 27, 59) or when an auxiliary contacts discrepancy is detected (52a and 52b).

TRIP BF

BF Breaker Failure

1A

B

A. CT at line sideB. CT at

star side

Protection elements

21NTG-Slide-03-2008 CT/VT monitoring

Fail of the voltage transformer and secondary connections are detectedAlarm and block of protective elements affected by loss of voltage (21-51V, 40, 27, 50+27, 37P)Following measuring are employed:

• three phase currents• three phase voltages• CB state

Fail of the current transformer and secondary connections are detectedAlarm and block of protective elements affected by loss of current (37P, 46,…).Following parameters are employed:

• residual current• residual voltage

74VT VT monitoring

74CT CT monitoring

22NTG-Slide-03-2008

MMI

Frequency tracking

Within the 20…80 Hz range, NTG change the sampling frequency to keep 16 samples per cycle

Measuring accuracy is assured during the start and stop of the generatort

I, UfN=80 Hz

t

I, U

t

I, U

fN=20 Hz

fN=50 Hz

23NTG-Slide-03-2008

MMI

Binary input allocations

Ext resetTwo profile switching (BANK A, BANK B)synchronizationLogic selectivityLogic block of protection functions

Trip Circuit Supervision

CB monitoring (operations, SI, SI2t, trip time)

Breaker failure (BF)

Thermal image resetReset countersReset CB diagnostic, (SI, SI2t, trip time)Reset timer 46Sequential tripping

8 binary inputs (standard) + 8 binary inputs

(optional), freely assignable with the following preset:

74CTS

BF

24NTG-Slide-03-2008

MMI

&

TRIP 32R (P->>)

TRIP 37P

TURBINE VALVE

CLOSED

MAIN AND FIELD CB OPEN

It is a stop procedure, planned or following delayed trip command, intended to avoid overspeeding

GT

VALVESTEAM

CB

P

SEQUENTIAL TRIPPING

The circuit breakers must be open after the turbine valve

has been closed,

When the power of the residual steam has been exhausted (and the active power is absorbed to drag the turbine).

Binary input allocations

25NTG-Slide-03-2008

MMI

Output relays allocation

GT

VALVE

C B A

talarm

SEQ TRIP.

FUEL FUEL

Type FunctionAA

87N27H

BB

4651V

BB

32R40

B 27C 26C 64F

A

very urgent protectionsB

little urgent protectionsC

not urgent protections

Example 1

GT

VALE

C B A

SEQ. TRIP

Operatorcommand

Example 2

8 output relays (normal) + 8 output relays

(optional) with one change-over contact.

The function of each relay is programmable with a matrix structure

Max flexibility for setting of the tripping ways

talarm

26NTG-Slide-03-2008 Application examples

G 81>

81<

46G

81<

51V

46T

40

32R

49

59

27

Low power diesel emergency generator (< 1 MVA) transformer-generator parallel grid connect (> 1 MVA, < 10 MVA)

BASIC

Diesel

51G

50/51

49

81>

81<

59

27

59NBA

SIC

27NTG-Slide-03-2008

MMI

GG

81<

64F

59N

87N

81>

81<

50+27

59

27

74VT

32

BF

74CT

G

81<

21

64F

59N

40

32R

27H

46

26

81>

81<

24

59

2759N

59H

74VT

BF

74CT

Transformer-generator (>10 MVA)

PRO26

37P

51V

40

32R

46

alternative

PRO

Parallel generators on the same bus (>10 MVA)

Application examples

28NTG-Slide-03-2008 ThySetter

PC

Setting & monitoring sw

Display, modify and print of settingsEvent recorder reading and printParameters reading and storeLogical states visualization Off-line setting filesDownload and uploadReset commandsUser friendly

RS232 (RJ10)

29NTG-Slide-03-2008

MMI

ThySetter

Frequency fPhase currents IL1, IL2, IL3 (RMS)Residual current IE (RMS)Negative and positive sequence currents I1, I2Thermal image DqPhase voltages UL1, UL2, UL3, line-to line voltages U12, U23, U31 (RMS), negative sequence voltage U2Residual voltage UEThird harmonic residual voltage UE3HReal and reactive power (RMS)Apparent Power

Phase power factor Impedance Z, resistance R and reactance X (40) Z power factor cosfZInsulation Resistance (64F)Temperature through thermal probesRTD1…8 Trip counters, start, blocks, CB operations, SI, SI2tBinary inputs state DIG-IN1...16Output relays state K1...K16Logical block stateLogic selectivity I/O stateElement state

Read

30NTG-Slide-03-2008

MMI

ThySetter

date, timecausefrequencyphase currents IL1,IL2,IL3residual current IEphase voltage UL1,UL2,UL3residual voltage UEthird harmonic component of residual voltage UE3Htotal active power Pfluxinsulation resistance (64F)temperature pt100impedance Z (40)Z resistive component RZ reactive component XZ power factor cosfZbinary inputs state DIG-IN1...16output relays state K1...K16

Event recorder

31NTG-Slide-03-2008

MMI

Communication

Ethernet connections with Modbus

TCP/IP protocol

32NTG-Slide-03-2008

MMI

Modbus

TCP/IP

Modbus protocol implementation on Ethernet networkssame protocol and available for a lot of devicesbaud rate increase from 19.2 kBps to 10 or 100 MBpsmixed systems can be built with TCP/IP and RS485 devices by means of gatewaysmultimaster networksunlimited Ethernet network (Internet)the Modbus TCP/IP protocol make use of Modbus messages for the application layer and the TCP/IP protocols forthe Ethernet transfersthe NTG is a generic element of the network equipped with an IP address like a common PC

Modbus

TCP/IP features