Buyer's Guide Transformer protection IED RET 670 - ABB

48 Pages·2007·3.1 MB·English

Transformer protection IED Buyer's Guide
RET 670 Pre-configured
1MRK 504 080-BEN
Revision: G
Issued: February 2007
Data subject to change without notice
Page 1
Features • Four configuration alternatives for single- or - Each step can be inverse or definite time
multi-breaker arrangements available – ready to delayed
connect
- Each step can be directional or non-direc-
• For power transformers, autotransformers, shunt tional
reactors, T-protection, generator transformer - Each step can be blocked on second har-
blocks, phase shifting transformers and small monic component
busbar systems
• Synchrocheck function for single- or
• For two- and three-winding transformers with up multi-breaker arrangements:
to six stabilized inputs
- Selectable energizing direction
• For multi- or single-breaker arrangements
- Two functions with built-in voltage selection
• Transformer differential protection with:
• Selectable additional software functions such as
- Percentage bias restraint for through faults breaker failure protection for each breaker, volt-
age protection, overexcitation protection, control
- Waveform and Second harmonic restraint for
and monitoring
transformer inrush
- Fifth harmonic restraint for overexcitation • Tripping from Buchholtz, temperature devices
etc. through binary inputs stabilized against
- High sensitivity for interturn faults capacitive discharges
• Restricted earth fault protection for all direct or • Built-in data communication modules for station
low impedance earthed windings bus IEC 61850-8-1
- Extremely fast operation • Data communication modules for station bus
- High sensitivity IEC 60870-5-103, LON and SPA
- High and low impedance based • Integrated disturbance and event recorder for up
to 40 analog and 96 binary signals
• Full scheme phase-to-phase and phase-to-earth
distance protection with up to four zones: • Time synchronization over IEC 61850-8-1, LON,
SPA, binary input or with optional GPS module
- Load encroachment feature
• Instantaneous high speed short circuit function • Analog measurements accuracy up to below
with low transient overreach 0.5% for power and 0.25% for current and volt-
age and with site calibration to optimize total
• Directional overcurrent protection with four steps accuracy
for each winding
• Versatile local human-machine interface
- Each step can be inverse or definite time
delayed • Extensive self-supervision with internal event
recorder
- Each step can be directional or non-direc-
tional • Six independent groups of complete setting
parameters with password protection
• Instantaneous high speed earth fault function
with low transient overreach • Powerful software PC tool for setting, distur-
bance evaluation and configuration
• Directional earth fault protection with four stages
for each winding • Remote end data communication modules for
C37.94 and G.703
Transformer protection IED RET 670 Buyer's Guide
Pre-configured
1MRK 504 080-BEN
Revision: G, Page 2
Application RET 670 provides fast and selective protection, age and over/under frequency protection functions
monitoring and control for two- and three-winding are also available.
transformers, autotransformers, generator-trans-
former units, phase shifting transformers, special Built-in disturbance and event recorder provides
railway transformers and shunt reactors. The trans- valuable data to the user about status and operation
former IED is designed to operate correctly over a for post-fault disturbance analysis.
wide frequency range in order to accommodate
Breaker failure protection for each transformer
power system frequency variations during distur-
breaker allow high speed back-up tripping of sur-
bances and generator start-up and shut-down.
rounding breakers.
A very fast differential protection function, with
The IED can also be provided with a full control
automatic CT ratio matching and vector group
and interlocking functionality including Synchro-
compensation, makes this IED the ideal solution
check function to allow integration of the main or
even for the most demanding applications.
a local back-up control.
RET 670 has very low requirements on the main
CTs, no interposing CTs are required. It is suitable
The advanced logic capability, where user logic is
for differential applications with multi-breaker
prepared with a graphical tool, allows special
arrangements with up to six restraint CT inputs.
applications such as automatic opening of discon-
The differential protection function is provided
nectors in multi-breaker arrangements, closing of
with 2nd harmonic and wave-block restraint fea-
breaker rings, load transfer logic etc. The graphical
tures to avoid tripping for magnetizing inrush, and
configuration tool ensures simple and fast testing
5th harmonic restraint to avoid tripping for overex-
and commissioning.
citation.
Serial data communication is via optical connec-
The differential function offers a high sensitivity
tions to ensure immunity against disturbances.
for low-level internal faults. RET 670's unique and
innovative sensitive differential protection fea- The wide application flexibility makes this product
ture, based on well-known theory of symmetrical an excellent choice for both new installations and
components provide best possible coverage for the refurbishment of existing installations.
winding internal turn-to-turn faults.
Four packages has been defined for following
A low impedance restricted earth-fault protection applications:
function is available as complimentary sensitive
and fast main protection against winding earth • Two winding transformer in single breaker
faults. This function includes a directional arrangements (A30)
zero-sequence current criterion for additional secu-
• Two winding transformer in multi breaker
rity.
arrangements (B30)
Alternatively a high impedance differential func- • Three winding transformer in single breaker
tion is available. It can be used as restricted earth
arrangements (A40)
fault or, as three functions are included, also as dif-
• Three winding transformer in multi breaker
ferential protection on autotransformers, as differ-
ential protection for a tertiary connected reactor, as arrangements (B40)
T-differential protection for the transformer feeder
in a mesh-corner or ring arrangement, as tertiary The packages are configured and set with basic
bus protection etc. functions active to allow direct use. Optional func-
tions are not configured but a maximum configura-
Tripping from Buchholz and temperature devices tion with all optional functions are available as
can be done through the IED where pulsing, template in the graphical configuration tool. An
lock-out etc. is performed. The binary inputs are alternative for Autotransformers is also available
heavily stabilized against disturbance to prevent as a configuration template. Interface to analogue
incorrect operations at e.g. dc system capacitive and binary IO are configurable from the Signal
discharges. matrix tool without need of configuration changes.
Analogue and tripping IO has been pre-defined for
Distance protection functionality for phase to
basic use on the, as standard supplied one binary
phase and/or phase to earth faults is available as
input module and one binary output module. Add
back-up protection for faults within the trans-
IO as required for your application at ordering.
former and in the connected power system.
Other signals need to be applied as required for
each application.
Versatile phase, earth, positive, negative and zero
sequence overcurrent functions, which can option-
For details on included basic functions, refer to
ally be made directional and/or voltage controlled,
chapter "Available functions".
provide further alternative backup protection.
Thermal overload, volts per hertz, over/under volt- The applications are shown in figures 1, 2, 3 and 4
for single resp. multi-breaker arrangement.
Transformer protection IED RET 670 Buyer's Guide
Pre-configured
1MRK 504 080-BEN
Revision: G, Page 3
TRIP BUSBAR
50BF
3I>
51/67
3I>
94/86 CB1
4
TRIP CB1
I->O 4
51N/67N
IN>
4
4
87N
IdN/I>
87T
3Id/I>
87N
IdN/I>
51N/67N
IN>
4
4
51/67
3I>
4
94/86 4
TRIP CB2 50BF
I->O
3I>
25
59 SC/VC
CB2
3U>
2
TRIP BUSBAR
2
27
3U<
2
2
en05000272.vsd
Figure 1: A typical protection application for a two winding transformer in single breaker arrangements is
shown on the figure. The system earthing principle and connection group will vary which gives
different detailed arrangements for each application.
Transformer protection IED RET 670 Buyer's Guide
Pre-configured
1MRK 504 080-BEN
Revision: G, Page 4
TRIP BUSBAR&CB2
TRIP CB1/3
CB1
50BF
51/67
3I>
3I> Σ 50BF
94/86
4 3I>
TRIP CB1
I->O 4
51N/67N
94/86 IN>
TRIP CB2 4 CB2
I->O
4
87N
IdN/I>
87T
3Id/I>
87N
IdN/I>
51N/67N
IN>
4
4
51/67
3I>
4
94/86 4
TRIP CB3
I->O 50BF
3I>
25
59 SC/VC
3U> CB3
2
TRIP BUSBAR
2
&CB1/2
27
3U<
2
2
en05000273.vsd
Figure 2: A typical protection application for a two winding transformer in multi breaker arrangements is
shown on the figure. The system earthing principle and connection group will vary which gives
different detailed arrangements for each application. Breaker failure function is here provided for
each breaker.
Transformer protection IED RET 670 Buyer's Guide
Pre-configured
1MRK 504 080-BEN
Revision: G, Page 5
TRIP BUSBAR
50BF
3I>
51/67
3I>
94/86
4 CB1
TRIP CB1
I->O 4
51N/67N
IN>
4
4
87N
IdN/I>
87T
3Id/I>
87N
IdN/I> TRIP BUSBAR 50BF
&CB1/2 3I>
51N/67N
IN>
4
3I>
4
4
51/67 4
3I>
4 94/86
94/86 4 I->O TRIP
CB3
TRIP CB2 50BF
I->O
3I>
25
SC/
59
VC CB2
3U>
2 59N
TRIP BUSBAR 2
UN>
&CB1/2/3
27 t2 2
2
3U<
2
2
en05000274.vsd
Figure 3: A typical protection application for a three winding transformer in single breaker arrangements is
shown on the figure. The system earthing principle and connection group will vary which gives
different detailed arrangements for each application.
Transformer protection IED RET 670 Buyer's Guide
Pre-configured
1MRK 504 080-BEN
Revision: G, Page 6
TRIP BUSBAR&CB2/3/4
CB1
50BF
TRIP CB1/3/4/X
51/67
3I>
50BF
94/86 3I> Σ
4 3I>
TRIP CB1
I->O 4
51N/67N
94/86 IN>
TRIP CB2 4 CB2
I->O
4
87N
IdN/I>
87T
3Id/I>
87N
IdN/I> TRIP BUSBAR 50BF
&CB1/2/3 3I>
51N/67N
IN>
4
3I>
4
4
51/67 4
3I>
4 94/86
94/86 4
I->O TRIP CB4
TRIP CB3
I->O 50BF
3I>
25
59 SC/VC
3U>
CB3
2 59N
TRIP BUSBAR
2 UN>
&CB1/2/4
2
27 t2
2
3U<
2
2
en05000275.vsd
Figure 4: A typical protection application for a three winding transformer in multi breaker arrangements is
shown on the figure. The system earthing principle and connection group will vary which gives
different detailed arrangements for each application. Breaker failure function is here provided for
each breaker.
Transformer protection IED RET 670 Buyer's Guide
Pre-configured
1MRK 504 080-BEN
Revision: G, Page 7
Available
functions
ANSI Function description Single breaker, Multi breaker, Single breaker, Multi breaker,
2 winding (A30) 2 winding (B30) 3 winding (A40) 3 winding (B40)
Basic Option Basic Option Basic Option Basic Option
(Qty/ (Qty/ (Qty/ (Qty/
option option option option
design) design) design) design)
Differential protection
87T Transformer differential protection, two winding (PDIF) 1 - 1 - - - - -
87T Transformer differential protection, three winding (PDIF) - - - - 1 - 1 -
87N Restricted earth fault protection (PDIF) 2 - 2 - 2 1/A01 2 1/A01
87 High impedance differential protection (PDIF) - 3/A02 - 3/A02 - 3/A02 - 3/A02
Distance protection
21 Distance protection zones (PDIS) - 4/B02 - 4/B02 - 4/B02 - 4/B02
21 Phase selection with load enchroachment (PDIS) - 1/B02 - 1/B02 - 1/B02 - 1/B02
Directional impedance (RDIR) - 1/B02 - 1/B02 - 1/B02 - 1/B02
78 Power Swing detection (RPSB) - 1/B02 - 1/B02 - 1/B02 - 1/B02
Current protection
50 Instantaneous phase overcurrent protection (PIOC) 2 - 2 - 3 - 3 -
51/67 Four step phase overcurrent protection (POCM) 2 - 2 - 3 - 3 -
50N Instantaneous residual overcurrent protection (PIOC) 2 - 2 - 3 - 3 -
51N/67 Four step residual overcurrent protection (PEFM) 2 - 2 - 3 - 3 -
N
49 Thermal overload protection, two time constants (PTTR) 1 1/C05 1 1/C05 2 1/C05 2 1/C05
50BF Breaker failure protection (RBRF) 2 - 4 - 3 - 6 -
52PD Pole-discordance protection (RPLD) 1 - 2 - 1 - 2 -
Voltage protection
27 Two step undervoltage protection (PUVM) 1 1/D01 1 1/D01 1 2/D02 1 2/D02
59 Two step overvoltage protection (POVM) 1 1/D01 1 1/D01 1 2/D02 1 2/D02
59N Two step residual overvoltage protection (POVM) 1 1/D01 1 1/D01 1 2/D02 1 2/D02
24 Overexcitation protection (PVPH) - 1/D03 - 1/D03 - 2/D04 - 2/D04
Frequency protection
81 Underfrequency protection (PTUF) - 6/E01 - 6/E01 - 6/E01 - 6/E01
81 Overfrequency protection (PTOF) - 6/E01 - 6/E01 - 6/E01 - 6/E01
81 Rate-of-change frequency protection (PFRC) - 6/E01 - 6/E01 - 6/E01 - 6/E01
Multipurpose protection
General current and voltage protection (GAPC) - 6/F02 - 6/F02 - 6/F02 - 6/F02
Secondary system supervision
Current circuit supervision (RDIF) 2 - 3 - 3 - 5 -
Fuse failure supervision (RFUF) 3 - 3 - 3 - 3 -
Control
25 Synchrocheck and energizing check (RSYN) 1 - 1 2/H01 1 3/H02 1 4/H03
Apparatus control for single bay, - 1/H08 - 1/H08 - 1/H08 - -
max 15 apparatuses (2CBs) incl. interlocking (APC15)
Apparatus control for up to 6 bays, - - - - - - - 1/H09
max 30 apparatuses incl. interlocking (APC30)
Logic
94 Tripping logic (PTRC) 2 - 3 - 5 - 6 -
Trip matrix logic (GGIO) 12 - 12 - 12 - 12 -
Monitoring
Measurements (MMXU) 3/10/3 - 3/10/3 - 3/10/3 - 3/10/3 -
Event counter (GGIO) 5 - 5 - 5 - 5 -
Transformer protection IED RET 670 Buyer's Guide
Pre-configured
1MRK 504 080-BEN
Revision: G, Page 8
ANSI Function description Single breaker, Multi breaker, Single breaker, Multi breaker,
2 winding (A30) 2 winding (B30) 3 winding (A40) 3 winding (B40)
Basic Option Basic Option Basic Option Basic Option
(Qty/ (Qty/ (Qty/ (Qty/
option option option option
design) design) design) design)
Disturbance report (RDRE) 1 - 1 - 1 - 1 -
Metering
Pulse counter logic (GGIO) 16 - 16 - 16 - 16 -
Station communication
IEC61850-8-1 Communication 1 - 1 - 1 - 1 -
LON communication protocol 1 - 1 - 1 - 1 -
SPA communication protocol 1 - 1 - 1 - 1 -
IEC60870-5-103 communication protocol 1 - 1 - 1 - 1 -
Single command, 16 signals 3 - 3 - 3 - 3 -
Multiple command and transmit 60/10 - 60/10 - 60/10 - 60/10 -
Remote communication
Binary signal transfer 4 - 4 - 4 - 4 -
3-winding power trans-
former with all three wind-
Functionality Differential protection
ings connected
Transformer differential
protection (PDIF, 87T)
The RET 670 differential function for two winding
and three winding transformers is provided with xx05000052.vsd
internal CT ratio matching and vector group com- 3-winding power trans-
former with 2 circuit break-
pensation, which allows connection directly to star
ers and 2 CT-sets on one
connected main CTs. Zero sequence current elimi-
side
nation is made internally in the software.
The function can be provided with up to six three
phase sets of current inputs. All current inputs are
xx05000053.vsd
provided with percentage bias restraint features,
Autotransformer with 2 cir-
making the RET 670 suitable for two- or three
cuit breakers and 2
winding transformers in multi-breaker station CT-sets on 2 out of 3 sides
arrangements.
2-winding applications
2-winding power trans-
former
xx05000057.vsd
xx05000048.vsd
2-winding power trans-
Figure 5: CT group arrangement for differential
former with unconnected
delta tertiary winding protection and other protections
xx05000049.vsd
2-winding power trans-
The setting facilities cover for applications of the
former with 2 circuit break-
ers on one side differential protection to all types of power trans-
formers and autotransformers with or without
xx05000050.vsd
on-load tap-changer as well as for shunt reactor or
2-winding power trans-
a local feeder within the station. An adaptive stabi-
former with 2 circuit break-
ers and 2 CT-sets on both lizing feature is included for heavy through-faults.
sides By introducing the tap changer position, the differ-
ential protection pick-up can be set to optimum
sensitivity covering internal faults with low fault
level.
xx05000051.vsd
Stabilization is included for inrush currents respec-
3-winding applications
tively for overexcitation condition. Adaptive stabi-
lization is also included for system recovery inrush
and CT saturation for external faults. A fast high
Transformer protection IED RET 670 Buyer's Guide
Pre-configured
1MRK 504 080-BEN
Revision: G, Page 9
set unrestrained differential current protection is The distance protection zones can operate, inde-
included for very high speed tripping at high inter- pendent of each other, in directional (forward or
nal fault currents. reverse) or non-directional mode.
Innovative sensitive differential protection feature,
Power swing detection (RPSB, 78)
based on the theory of symmetrical components,
Power swings may occur after disconnection of
offers best possible coverage for power trans-
heavy loads or trip of big generation plants.
former windings turn-to-turn faults.
Power swing detection function is used to detect
Restricted earth fault power swings and initiate block of selected dis-
protection (PDIF, 87N) tance protection zones. Occurrence of earth fault
Three low impedance restricted earth fault func- currents during a power swing can block the power
tions can be included in RET 670. The function swing detection function to allow fault clearance.
can be used on all directly or low impedance
earthed windings. The restricted earth fault func-
Current protection
tion can provide higher sensitivity (down to 5%)
and higher speed as it measures individually on
each winding and thus do not need harmonics sta- Instantaneous phase overcurrent
bilization. protection (PIOC, 50)
The instantaneous three phase overcurrent function
The low impedance function is a percentage biased has a low transient overreach and short tripping
function with an additional zero sequence current time to allow use as a high set short-circuit protec-
directional comparison criteria. This gives excel- tion function, with the reach limited to less than
lent stability for through faults. The function typical eighty percent of the power transformer at
allows use of different CT ratios and magnetizing minimum source impedance.
characteristics on the phase and neutral CT cores
and mixing with other functions and protection Four step phase overcurrent
IED's on the same cores. protection (POCM, 51_67)
The four step phase overcurrent function has an
inverse or definite time delay independent for each
step separately.
All IEC and ANSI time delayed characteristics are
available together with an optional user defined
time characteristic.
The function can be set to be directional or
non-directional independently for each of the
xx05000058.vsd
steps.
Figure 6: Autotransformer low-impedance REF
Instantaneous residual overcurrent
protection (PIOC, 50N)
High impedance differential protection
The single input overcurrent function has a low
(PDIF, 87)
transient overreach and short tripping times to
The high impedance differential protection can be
allow use as a high set short circuit protection
used when the involved CT cores have same turn
function, with the reach limited to less than typical
ratio and similar magnetizing characteristic. It uti-
eighty percent of the power transformer at mini-
lizes an external summation of the phases and neu-
mum source impedance. The function can be con-
tral current and a series resistor and a voltage
figured to measure the residual current from the
dependent resistor externally to the relay.
three phase current inputs or the current from a
separate current input.
Distance protection
Four step residual overcurrent
Distance protection zones (PDIS, 21) protection (PEFM, 51N/67N)
The distance protection is a four zone full scheme The four step single input overcurrent function has
protection with three fault loops for phase to phase an inverse or definite time delay independent for
faults and three fault loops for phase to earth fault each step separately.
for each of the independent zones. Individual set-
All IEC and ANSI time delayed characteristics are
tings for each zone resistive and reactive reach
available together with an optional user defined
gives flexibility for use as back-up protection for
characteristic.
transformer connected to overhead lines and
cables.
The function can be set to be directional, forward,
reverse or non-directional independently for each
The function has a functionality for load encroach-
of the steps.
ment which increases the possibility to detect high
resistive faults on heavily loaded lines.
Transformer protection IED RET 670 Buyer's Guide
Pre-configured
1MRK 504 080-BEN
Revision: G, Page 10
A second harmonic blocking can be set individu- machines and can cause unwanted operation of
ally for each step. zero sequence current functions.
The function can be used as main protection for Normally the own breaker is tripped to correct the
phase to earth faults. positions. If the situation consists the remote end
can be intertripped to clear the unsymmetrical load
The function can be configured to measure the situation.
residual current from the three phase current inputs
or the current from a separate current input. The pole discordance function operates based on
information from auxiliary contacts of the circuit
Thermal overload protection, two time breaker for the three phases with additional criteria
constants (PTTR, 49) from unsymmetrical phase current when required.
If the temperature of a power transformer reaches
too high values the equipment might be damaged.
Voltage protection
The insulation within the transformer will have
forced ageing. As a consequence of this the risk of
internal phase to phase or phase to earth faults will Two step undervoltage
increase. High temperature will degrade the qual- protection (PUVM, 27)
ity of the transformer oil. Undervoltages can occur in the power system dur-
ing faults or abnormal conditions. The function
The thermal overload protection estimates the can be used to open circuit breakers to prepare for
internal heat content of the transformer (tempera- system restoration at power outages or as
ture) continuously. This estimation is made by long-time delayed back-up to primary protection.
using a thermal model of the transformer with two
time constants, which is based on current measure- The function has two voltage steps, each with
ment. inverse or definite time delay.
Two warning levels are available. This enables Two step overvoltage
actions in the power system to be done before dan- protection (POVM, 59)
gerous temperatures are reached. If the tempera- Overvoltages will occur in the power system dur-
ture continues to increase to the trip value, the ing abnormal conditions such as sudden power
protection initiates trip of the protected trans- loss, tap changer regulating failures, open line
former. ends on long lines.
Breaker failure protection (RBRF, 50BF) The function can be used as open line end detector,
The circuit breaker failure function ensures fast normally then combined with directional reactive
back-up tripping of surrounding breakers. The over-power function or as system voltage supervi-
breaker failure protection operation can be current sion, normally then giving alarm only or switching
based, contact based or adaptive combination in reactors or switch out capacitor banks to control
between these two principles. the voltage.
A current check with extremely short reset time is The function has two voltage steps, each of them
used as a check criteria to achieve a high security with inverse or definite time delayed.
against unnecessary operation.
The overvoltage function has an extremely high
The breaker failure protection can be single- or reset ratio to allow setting close to system service
three-phase started to allow use with single phase voltage.
tripping applications. For the three-phase version
of the breaker failure protection the current criteria Two step residual overvoltage
can be set to operate only if two out of four e.g. protection (POVM, 59N)
two phases or one phase plus the residual current Residual voltages will occur in the power system
starts. This gives a higher security to the back-up during earth faults.
trip command.
The function can be configured to calculate the
The function can be programmed to give a single- residual voltage from the three phase voltage input
or three phase re-trip of the own breaker to avoid transformers or from a single phase voltage input
unnecessary tripping of surrounding breakers at an transformer fed from an open delta or neutral point
incorrect starting due to mistakes during testing. voltage transformer.
The function has two voltage steps, each with
Pole discordance protection (RPLD, 52PD)
inverse or definite time delayed.
Single pole operated circuit breakers can due to
electrical or mechanical failures end up with the
Overexcitation protection (PVPH, 24)
different poles in different positions (close-open).
When the laminated core of a power transformer is
This can cause negative and zero sequence cur-
subjected to a magnetic flux density beyond its
rents which gives thermal stress on rotating
design limits, stray flux will flow into non-lami-
nated components not designed to carry flux and