ABB RET 541 User manual

Transformer Terminal
Product Guide
RET 541,
RET 543,
RET 545

3
Transformer Terminal RET 541, RET 543, RET 545
Features • Transformer terminal for protection, control,
measurement and supervision of two-wind-
ing power transformers and generator-
transformer blocks in distribution networks
• Designed to withstand harsh environments
e.g. in heavy industry, marine and offshore
applications
• Three-phase current differential protection
with stabilized and instantaneous stages
for fast and selective winding short-circuit
and interturn fault protection as main pro-
tection
• Fast and reliable operation even with satu-
rating CTs
• Numerical implementation of vector group
matching allows wye-connection of mea-
suring CTs as standard without interposing
CTs, irrespective of transformer vector
group
• Restricted earth-fault protection with the
conventional high impedance principle or
the stabilized numerical principle
• Three-phase overcurrent and earth-fault
back-up protection with definite time and
IDMT characteristics for both windings
• Thermal overload and negative phase
sequence protection
• Additional protection functions available in
the Multi –version terminal: overexcitation,
overvoltage, undervoltage, residual over-
voltage, directional overcurrent and earth-
fault, overfrequency, underfrequency and
underimpedance line back-up protection
• Large graphic display, either integrated or
as an external module
• Control functions including local and
remote control of switching objects, includ-
ing object status indication and interlock-
ings on bay and substation level
• Optional automatic on-load tap-changer
control function for single or parallel trans-
formers using the Master-Follower, Nega-
tive Reactance or Minimizing Circulating
Current principles
• Supports several methods to interface tap-
changer position information to differential
protection and voltage regulator
• Measurement of two sets of three-phase
currents, phase-to-phase or phase to neu-
tral voltages, neutral current, residual volt-
age, frequency, power factor, active and
reactive power and energy
• Condition monitoring including circuit-
breaker condition monitoring, trip circuit
supervision and internal self-supervision of
the transformer terminal
• Extensive set of integrated communication
protocols: SPA, LON, IEC 60870-5-103,
Modbus RTU/ASCII, DNP 3.0
• Interface to Profibus DP and IEC 61850
based systems via adapters
• Part of ABB’s substation automation sys-
tem
ret54_mimic_co180dpi
Fig. 1 Mimic view of RET 54_ transformer termi-
nal.
1MRS755543
Issued: February 2005
Status: Updated
Version: E/26.10.2010
Data subject to change without notice

Transformer Terminal RET 541, RET 543, RET 545
1MRS755543
4
Application The RET 541/543/545 transformer terminals
are designed to be used for the protection,
control, measurement and supervision of two-
winding power transformers and generator-
transformer blocks in distribution networks.
RET 54_ terminals can also be used in harsh
environments e.g. in heavy industry, marine
and offshore applications.
The main protection function is three-phase
current differential protection with stabilized
and instantaneous stages for fast and selective
winding short-circuit and interturn protection.
Besides 2nd and 5th harmonic restraints, the
stabilized stage also includes a waveform rec-
ognition-based blocking-deblocking feature.
Reliable operation even with partially saturat-
ed current transformers, that is, short operate
times at faults occurring in the zone to be pro-
tected and high stability at external faults are
achieved. Increased sensitivity can be obtain-
ed by automatic adaptation to the position
changes of the on load tap changer. Interpos-
ing current transformers are not needed: Any
vector group matching and CT ratio correc-
tions in a wide range are numerically imple-
mented as well as zero-sequence current
elimination, which prevents unwanted trips at
earth faults occurring outside the protected
area.
In addition to the differential protection, the
Basic version terminals incorporate the fol-
lowing protections: Restricted earth fault pro-
tection with stabilized numerical or high
impedance principle, unbalance and thermal
overload protections, three phase overcurrent
and non-directional earth fault back-up pro-
tection with definite and IDMT characteris-
tics on both sides of the transformer.
The Multi-version terminals, further includ-
ing overvoltage and undervoltage, residual
overvoltage, underfrequency and overfre-
quency, overexcitation, directional earth-
fault, directional overcurrent and under-
impedance line back-up protections fulfill the
most demanding application requirements.
Enhanced with the optional automatic voltage
regulation function, the RET 54_ terminal
can be applied as a comprehensive integrated
transformer management terminal. The volt-
age regulator can be applied for a single
transformer or for parallel transformers with
Master-Follower, Negative Reactance or
Minimizing Circulating Current principles.
A special control version terminal with volt-
age regulator and control functions can be
applied, when integration of voltage regula-
tion and protection is not allowed.
The graphical configuration tool, based on
the IEC 61131-3 standard, enables easy cre-
ation of application-specific configurations
and MIMIC pictures corresponding to differ-
ent switchgear systems. The process status is
shown on a dynamic large graphical display.
Detailed information, for instance, measured
values, events and application-specific
alarms, are presented in the display views.
The RET 54_ terminals can measure two sets
of three phase currents, phase-to-phase or
phase-to-earth voltages, neutral current,
residual voltage, frequency and power factor.
Active and reactive power is calculated from
the measured currents and voltages. Energy
can be calculated on the basis of the mea-
sured power. The measured values can be
indicated locally and remotely as scaled pri-
mary values.
With the condition monitoring functions the
RET 54_ transformer terminal monitors e.g.
trip circuits, gas pressure of the breaker and
breaker wear and provides scheduled time
intervals for maintenance.
The RTD1 card, available as an option to the
RET 541 and RET 543 terminals, provides
versatile analog inputs enabling e.g. tap posi-
tion supervision of the on load tap changer,
RTD inputs for top and bottom oil tempera-
ture monitoring, and ambient temperature
biasing for accurate thermal overload protec-
tion. The mA outputs allow transfer of any
measurement data e.g. to PLCs.
By means of the graphic HMI display, the
control functions in the transformer terminal
indicate the position of disconnectors, circuit
breakers and tap changer locally. Local con-
trol of these objects is possible via the push
buttons on the front panel of the terminal.
Furthermore, the terminal allows position
information of the objects to be transmitted to
the remote control system. Controllable
objects, such as CBs, can also be opened and
closed over the remote control system.
Supporting a wide range of communication
protocols, including SPA, LON, IEC 60870-
5-103, DNP 3.0 and Modbus RTU/ASCII,
commonly used by utilities and industries, the
terminals are flexibly integrated into different
control systems. Connection to Profibus DP
or IEC 61850 based system is possible via the
interface adapters SPA-ZC 302 or SPA-ZC
400, respectively.

Transformer Terminal RET 541, RET 543, RET 545
1MRS755543
5
Design The transformer terminals RET 541, RET
543 and RET 545 differ from each other
regarding the number of digital inputs and
outputs available. Please, refer to section
“Ordering” for more details.
The functions of the RET 54_ transformer
terminal are categorized as:
• protection functions
• measurement functions
• control functions
• condition monitoring functions
• communication functions
• general functions
• standard functions
The functions are further divided to three sub-
sets that correspond to different functionality
levels, refer to section “Ordering Informa-
tion”
Protection functions
Protection is one of the most important func-
tions of the RET 54_ transformer terminal.
The protection function blocks (e.g.
NOC3Low) are independent of each other
and have e.g. their own setting groups and
data recording.
The protection function blocks are docu-
mented on the CD-ROM “Technical Descrip-
tions of Functions” (1MRS750889-MCD)
Measurement functions
The measurement function blocks are docu-
mented on the CD-ROM “Technical Descrip-
tions of Functions” (1MRS750889-MCD)
Control functions
The control functions are used to indicate the
position of switching devices, i.e. circuit
breakers and disconnectors, and to execute
open and close commands for controllable
switching devices in the switchgear. Further-
more, there are supplementary functions for
control logic purposes, e.g. on/off switches,
MIMIC alarm, LED control, numerical data
for the MIMIC and logic controlled position
selection.
The control functions configured using the
Relay Configuration Tool can be associated
with position indicators that are part of the
MIMIC configuration picture displayed on
the HMI. Position indicators are used to indi-
cate the position of switching devices via the
MIMIC picture and to control them locally.
The control function blocks are documented
on the CD-ROM “Technical Descriptions of
Functions” (1MRS750889-MCD)
Condition monitoring functions
The condition monitoring function blocks are
documented on the CD-ROM “Technical
Descriptions of Functions” (1MRS750889-
MCD)
General functions
Additional functions are available for differ-
ent general purposes to be used in logics such
as activation of HMI backlight, switchgroups,
and resetting of operation indications, latched
output signals, registers and disturbance
recorder.
Communication functions
The RET 54_ transformer terminal provides
the IEC_103, Modbus, DNP 3.0, SPA and
LON serial communication protocols.
In a customer-specific transformer terminal
configuration, special events can be gener-
ated via an EVENT230 event function.
EVENT230 is documented on the CD-ROM
“Technical descriptions of Functions”
(1MRS750889-MCD).
Standard functions
Standard functions are used for logics, such
as interlocking, alarming and control
sequencing. The use of logic functions is not
limited and the functions can be intercon-
nected with each other as well as with protec-
tion, measurement, power quality, control,
condition monitoring and general functions.
In addition, the digital inputs and outputs as
well as LON inputs and outputs can be con-
nected to standard functions by using the
Relay Configuration Tool.
The standard function blocks are documented
on the CD-ROM “Technical descriptions of
Functions” (1MRS750889-MCD).
Other functions
Low auxiliary voltage indication
The RET 54_ transformer terminal is pro-
vided with a low auxiliary voltage indication
feature. The power supply module issues an
internal alarm signal when a drop in the
power supply voltage is detected (ACFail,
active low). The alarm signal is activated if
the power supply voltage falls about 10%
below the lowest rated DC input voltage of
the power supply module.

Transformer Terminal RET 541, RET 543,
RET 545
1MRS755543
Design (cont´d)
6
The indication of a low auxiliary voltage is
available in the transformer terminal configu-
ration and can be connected to any signal out-
put of the RET 54_.
Overtemperature indication
The RET 54_ transformer terminal includes
an internal temperature supervision function.
The power supply module issues an internal
alarm signal when overtemperature has been
detected inside the terminal enclosure. The
alarm signal will be activated once the tem-
perature inside the terminal enclosure
increases to +78C (+75...+83C). Over-
temperature indication is available in the
transformer terminal configuration and can be
connected to any signal output of the RET
54_.
Analog channels
The transformer terminal measures the analog
signals needed for protection, measuring, etc.
via galvanically separated matching trans-
formers.
RET 54_ transformer terminals have 9 analog
channels. Furthermore, the transformer termi-
nal includes virtual analog channels for calcu-
lating the residual current and residual
voltage from phase currents and voltages.
Both the amplitude and the phase angle are
calculated for the virtual channels.
Note! When sensitive earth-fault protection is
needed, core balance transformers are not
recommended to be replaced with the numer-
ically derived sum of phase currents. Nor-
mally, an earth-fault setting below 10% of the
rated value requires the use of a core balance
transformer.
Analog channels of the transformer terminal
are configured with the CAP 505 Relay Prod-
uct Engineering Tools.
A separate scaling factor can be set for each
analog channel. The factors enable differ-
ences between the ratings of the protected
unit and those of the measuring device (CT
and VT ratio corrections). The setting value
1.00 means that the rated value of the pro-
tected unit is exactly the same as that of the
measuring device.
Digital inputs
The digital inputs of the transformer termi-
nals are voltage controlled and optically iso-
lated with three treshold voltages defined by
the order, see chapter “Ordering”. The func-
tion of a digital input can be inverted. The
programmable filter time removes debounces
and short disturbances on a digital input. The
filter time can be set for each digital input
separately.
Some specific digital inputs can be pro-
grammed to operate either as digital inputs, as
pulse counters or as used for time synchroni-
zation. When a digital input operates as a
pulse counter, pulse counting frequency can
be up to100 Hz.
Oscillation suppression
The transformer terminals have two global
parameters for the suppression of digital input
oscillation. The settings of these parameters
determine the oscillation level and hysteresis
for all digital inputs. Event is generated in
case oscillation is detected.
Attributes of a digital input for transformer
terminal configuration
For each digital input, the status of the input
(value), the time tag for the status change
(time) and the validity of the digital input
(invalidity) can be issued by the attributes.
These attributes are available in the trans-
former terminal configuration and can be
used for various purposes.
RTD/analog inputs
The RET 541 and RET 543 transformer ter-
minals equipped with an RTD/analog module
(RTD1) have eight general purpose analog
inputs for DC measurement. The RTD/analog
inputs are galvanically isolated from the
transformer terminal power supply and enclo-
sure. However, the inputs have a common
ground. The general purpose RTD/analog
inputs accept voltage-, current- or resistance-
type signals. For each measuring mode, a
separate parameter is provided for choosing
between the available measurement ranges.
RTD/analog inputs can be applied for e.g.
temperature measurement.
Digital outputs
The outputs of the transformer terminal are
categorized as follows:
• HSPO: High-speed power output, double-
pole contact, preferred for tripping pur-
poses and for circuit breaker and discon-
nector control
• PO: Power output, either single-pole or
double-pole contact, preferred for circuit
breaker and disconnector control

Transformer Terminal RET 541, RET 543, RET 545
1MRS755543
7
• SO: Signal output, either NO (Normally
Open) or NO/NC (Normally Open/Nor-
mally Closed) contact. The output contact
is a normal-duty contact and cannot be
used for controlling a heavy load such as a
circuit breaker.
Analog outputs
The RET 541 and RET 543 transformer ter-
minals equipped with an RTD/analog module
have four general purpose 0...20 mA analog
current outputs. All outputs are galvanically
isolated from the supply and enclosure of the
transformer terminal and from each other.
Analog outputs can be utilized for transfer-
ring any measured or calculated information
to panel meters or e.g. PLCs.
Alarm LED indicators
The transformer terminal offers eight alarm
LED indicators to be configured with the
Relay Mimic Editor. The LED colours (green,
yellow, red), their use, and the ON and OFF
state texts can be freely defined. Three basic
operation modes are supported: non-latched,
latched-steady and latched flashflashing.
Alarms can be acknowledged remotely,
locally or by using logic of the transformer
terminal.
The alarm channels include time tagging for
detected alarms. The time tagging principle
used depends on the operation mode.
Interlocking LED indicator
The interlocking LED indicates that control
operation has been interlocked or that the
interlocking is in bybass mode, e.g. when
control is possible despite of interlocking.
Trip Circuit Supervision
The purpose of this function is to supervise
the tripping circuitry of the circuit breaker.
An alarm will be generated in case a faulty
tripping circuit, e.g. a circuit is not able to
perform a trip, is detected.
The supervision is based on the constant-cur-
rent injection through the tripping circuitry.
Display panel The transformer terminal is provided with
either a fixed display or an external display
module. The external display module requires
a separate voltage supply from a common
source with the main unit. The display con-
sists of 19 rows divided into two windows: a
main window (17 rows) and an assisting win-
dow (2 rows).
The graphic display presents detailed infor-
mation on MIMIC, objects, events, measure-
ments, control alarms, and parameters. The
assisting window is used for terminal-depen-
dent indications/alarms and help messages.
Additionally, the panel includes the following
HMI items:
• three push-buttons for object control (I, O,
object selection)
• eight freely programmable alarm LEDs
with different colours and modes accord-
ing to the configuration
• LED indicator for control interlocking
• three protection LED indicators
• HMI push-button section with four arrow
buttons and buttons for clear and enter
• optically isolated serial communication
port
• backlight and contrast control
• freely programmable button (F) which can
be used in the configuration of the trans-
former terminal
• a button for remote/local control
HMI has two main levels, the user level and
the technical level. The user level is for
“everyday” measurements and monitoring
whereas the technical level is intended for
advanced transformer terminal programming.
Unauthorized access can be prevented with
passwords.
Serial commu-
nication
The transformer terminal has three serial
communication ports, one on the front panel
and two on the rear panel.
The standard optical ABB connector
The standard optical ABB connector (RS-232
connection) on the front panel is intended for
the connection of a PC for configuring the
transformer terminal with the CAP 50_ tools.
The front interface uses the SPA bus protocol.
SPA/IEC_103/DNP 3.0/Modbus communi-
cation on the rear connector X3.2
The 9-pin D-type subminiature male connec-
tor (RS-232 connection) on the rear panel
connects the transformer terminal to the dis-
tribution automation system via the SPA bus,
IEC_103, DNP 3.0 or Modbus. The fibre-
optic interface module type RER 123 is used
to connect the transformer terminal to the
fibre-optic communication bus for SPA and

Transformer Terminal RET 541, RET 543, RET 545
1MRS755543
8
IEC_103 protocols. RS-485 interface module
RER 133 is used to connect the transformer
terminal to the RS-485 communication bus
for DNP 3.0 and Modbus.
LON/SPA bus communication on the rear
connector X3.3
The 9-pin D-type subminiature female con-
nector (RS-485 connection) on the rear panel
connects the transformer terminal to the sub-
station automation system via the SPA bus or
the LON bus. The fibre-optic interface module
type RER 103 is used to connect the trans-
former terminal to the fibre-optic communi-
cation bus. The RER 103 module supports
both SPA bus and LON bus communication.
The SPA-ZC 302 is an interface module that
provides connectivity to the Profibus DP
fieldbus and SPA-ZC 400 interface module
provides connectivity to the IEC 61850-8-1
Station bus.
Self-supervision
The transformer terminal RET 54_ is pro-
vided with an extensive self-supervision sys-
tem. The self-supervision system handles
run-time fault situations and informs the user
of faults via the HMI and LON/SPA bus com-
munication.
When a fault has been detected, the green
Ready indicator starts flashing, a fault indica-
tion text is displayed on the HMI and an
event 0/E57 is generated. The fault indication
text on the HMI consists of two rows: a gen-
eral message ‘internal fault’, followed by the
generated IRF code of the fault.
The relay will try to recover from a fault
either by restarting the module (I/O module
or HMI) that reported the fault, or by restart-
ing the whole relay. During restarting the IRF
state will remain active until the internal self-
supervision program has determined that the
relay is operating normally. If the fault is still
persistent after restarting three times, the
relay will be in permanent IRF state.
Transformer
terminal
configuration
The Relay Configuration Tool, based on the
IEC 61131-3 standard and included in the
CAP 505 Relay Product Engineering Tools, is
used for configuring the basic terminal, pro-
tection and logic function blocks, control and
measurement functions, timers and other
functional elements included in the logic
functions category.
The programmable system of RET 54_ trans-
former terminals allows the output contacts to
be operated in accordance with the state of
the logic inputs and the outputs of the protec-
tion, control, measurement and condition
monitoring functions. The PLC functions
(e.g. interlocking and alarm logic) are pro-
grammed with Boolean functions, timers,
counters, comparators and flip-flops. The
program is written in a graphic function block
diagram language by using the configuration
software.
Mimic configuration with Relay Mimic Edi-
tor
The Relay Mimic Editor, which is included in
the CAP 505 Relay Product Engineering
Tools, is used for configuring the graphic dis-
play and the alarm channels of the trans-
former terminal. The mimic configuration
may include circuit breakers, disconnectors,
indicators, measurement data objects and
user-defined texts and explanations. Any con-
figuration can be saved for later use.
All of the eight alarm function blocks can be
configured in the same alarm view of the
mimic editor. ON and OFF state texts (only
one language version at a time can be sup-
ported for the alarm) and LED colours can be
defined. Three different colours can be used
to define the ON and OFF state. Three basic
modes are available:
• non-latched
• latched-steady
• latched flashing
Interlocking LED texts can also be defined in
the same alarm view but the colour of the
interlocking LED cannot be changed.
LON network configuration
The LON Network Tool is used for binding
network variables between the transformer
terminal units. Typically, LON horizontal
communication is used for transferring object
status data (open, close, undefined) between
units for interlocking purposes. Additionally,
LON horizontal communication is used to
transfer measured current amplitude and
phase angle information between terminals,
when parallel control with MCC principle is
to be applied.
DNP 3.0 and Modbus configuration
The Protocol Mapping Tool is used for con-
figuring the DNP 3.0 and Modbus interfaces
of the transformer terminal.

Transformer Terminal RET 541, RET 543, RET 545
1MRS755543
9
Transformer ter-
minal parameter-
ization
The parameters of the transformer terminal
units can be set either locally over the HMI or
externally via the serial communication using
the Relay Engineering Tools CAP 501/505.
Local parameterization
When the parameters are set locally, the set-
ting parameters can be chosen from the hier-
archical menu structure. The desired
language for parameter description can be
selected.
External parameterization
The Relay Setting Tool is used for parameter-
izing and setting the transformer terminals
externally. The parameters can be set off-line
on a PC and downloaded to the transformer
terminal over a communication port. The
menu structure of the setting tool, including
views for parameterization and settings, is the
same as the menu structure of the transformer
terminal.
Auxiliary
voltage
For its operation, the RET 54_ terminal, in-
cluding the external display module, requires
a secured auxiliary voltage supply. The termi-
nal’s internal power supply module forms the
voltages required by the terminal electronics.
The power supply module is a galvanically
isolated (fly-back type) dc/dc converter. A
green protection LED indicator on the front
panel is lit when the power supply module is
in operation.
Power supply modules
There are two basic types of power supply
modules available for the RET 54_: type
PS1/_ and type PS2/_. The operating range of
digital inputs depends on the type of the
power supply module. See Technical data.
Terminal
connections
All external circuits are connected to the ter-
minal blocks on the rear panel, see figures
2...4. The terminal block for the measuring
transformers consists of fixed screw termi-
nals.
The serial interface RS-232 on the rear panel
is used for connecting the transformer termi-
nal to the SPA bus, the IEC_103, DNP 3.0 or
Modbus. The SPA/IEC_103 is connected via
a connection module type RER 123 fitted to
the 9-pin D-type subminiature connector and
screwed to the rear panel. DNP 3.0/Modbus
is connected via a connection module, type
RER 133.
The serial interface RS-485 on the rear panel
is used for connecting the transformer termi-
nal to the SPA bus or the LON bus. The
SPA/LON bus is connected via a connection
module type RER 103 fitted to the 9-pin D-
type subminiature connector and screwed to
the rear panel.
The digital input and output contacts of the
transformer terminal are connected to the
multi-pole connectors.
Protective earth is connected to the screw
marked with the earth symbol.

Transformer Terminal RET 541, RET 543, RET 545
1MRS755543
10
Terminal diagrams
1A
5A
100V
100V
1A
5A
1A
5A
1A
5A
X1.1
16
15
14
13
12
11
8
7
6
5
4
3
2
1
10
9
19
18
22
21
27
25
24
IRF
TCS
TCS
X4.1
5
6
7
9
8
10
11
13
12
15
16
18
17
3
4
11
10
12
13
15
14
16
17
18
8
9
X4.2
X3.3
+
-
X4.1
1
2
PS1_4_HSPO3
PS1_4_HSPO1
PS1_4_TCS1
PS1_4_HSPO2
PS1_4_HSPO5
PS1_4_SO1
PS1_4_TCS2
PS1_4_HSPO4
PS1_4_TempA arm
3
4
5
6
7
9
8
10
12
11
13
15
14
16
18
17
1
2
4
5
6
7
X4.2
PS1_4_BI1
PS1_4_BI3
PS1_4_BI2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
X5.1
1
2
X5.2
BIO1_5_BI1
BIO1_5_BI11
BIO1_5_BI9
BIO1_5_BI8
BIO1_5_BI7
BIO1_5_BI6
BIO1_5_BI5
BIO1_5_BI4
BIO1_5_BI3
BIO1_5_BI2
BIO1_5_BI10
BIO1_5_BI12
BIO1_5_SO1
BIO1_5_SO2
BIO1_5_SO3
BIO1_5_SO4
BIO1_5_SO5
BIO1_5_SO6
X5.2
PS1_4_ACFai
X3.2
1A
5A
1A
5A
1A
5A
+
+
-
-
-
-
-
-
-
-
-
-
-
RET 541
SERIAL BUS
Mains
Ch 2, CT1
Ch 3, CT2
Ch 4, CT3
Ch 5, CT4
Ch 6, VT1
Ch 7, CT5
Ch 8, CT6
Ch 9, CT7
Ch 10, VT2
SERIAL BUS
CD541
Fig. 2 Sample connection diagram of RET 541