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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
Recommended