ABB RET615 User manual

Relion® 615 series
Transformer Protection and Control
RET615
Product Guide

Contents
1. Description...........................................................3
2. Standard configurations.......................................3
3. Protections functions...........................................6
4. Application...........................................................9
5. Supported ABB solutions...................................11
6. Control................................................................13
7. Measurement.....................................................13
8. Disturbance recorder..........................................13
9. Event log.............................................................13
10. Recorded data...................................................13
11. Circuit-breaker monitoring................................14
12. Trip-circuit supervision......................................14
13. Self-supervision.................................................14
14. Access control...................................................14
15. Inputs and outputs............................................14
16. Communication.................................................15
17. Technical data...................................................17
18. Display options..................................................38
19. Mounting methods............................................39
20. IED case and IED plug-in unit...........................39
21. Selection and ordering data..............................40
22. Accessories and ordering data.........................43
23. Tools..................................................................44
24. Terminal diagrams.............................................45
25. References........................................................47
26. Functions, codes and symbols.........................47
27. Document revision history.................................50
Disclaimer
The information in this document is subject to change without notice and should not be construed as a commitment by ABB Oy. ABB Oy assumes
no responsibility for any errors that may appear in this document.
© Copyright 2009 ABB Oy.
All rights reserved.
Trademarks
ABB and Relion are registered trademarks of ABB Group. All other brand or product names mentioned in this document may be trademarks or
registered trademarks of their respective holders.
Transformer Protection and Control 1MRS756891 B
RET615
Product version: 2.0 Issued: 01.10.2009
2 ABB

1. Description
RET615 is a dedicated transformer protection
and control IED (intelligent electronic device)
for power transformers, unit and step-up
transformers including power generator-
transformer blocks in utility and industry
power distribution systems. RET615 is a
member of ABB’s Relion®product family and
part of its 615 protection and control product
series. The 615 series IEDs are characterized
by their compactness and withdrawable
design.
Re-engineered from the ground up, the 615
series has been designed to unleash the full
potential of the IEC 61850 standard for
communication and interoperability between
substation automation devices. Once the
standard configuration IED has been given
the application-specific settings, it can
directly be put into service.
The 615 series IEDs support a range of
communication protocols including IEC
61850 with GOOSE messaging, IEC
60870-5-103, Modbus®and DNP3.
2. Standard
configurations
The transformer protection and control IED
RET615 is available with four alternative
standard configurations.
Table 1. Standard configurations
Description Std.conf.
Three-phase transformer differential protection for two-winding transformers,
numerical restricted earth-fault protection for the high-voltage (HV) side A
Three-phase transformer differential protection for two-winding transformers,
numerical restricted earth-fault protection for the low-voltage (LV) side B
Three-phase transformer differential protection for two-winding transformers,
high-impedance based restricted earth-fault protection for the high-voltage
(HV) side
C
Three-phase transformer differential protection for two-winding transformers,
high-impedance based restricted earth-fault protection for the low-voltage (LV)
side
D
Transformer Protection and Control 1MRS756891 B
RET615
Product version: 2.0 Issued: 01.10.2009
Revision: B
ABB 3

Table 2. Supported functions
Functionality A B C D
Protection1)
Stabilized and instantaneous differential protection for two-
winding transformers ●●●●
Numerical stabilized low impedance restricted earth-fault
protection ● ● - -
High impedance based restricted earth-fault protection - - ● ●
Master Trip, instance 1 ●●●●
Master Trip, instance 2 ●●●●
HV-side protection
Three-phase non-directional overcurrent protection, low
stage, instance 1 ●●●●
Three-phase non-directional overcurrent protection, high
stage, instance 1 ●●●●
Three-phase non-directional overcurrent protection,
instantaneous stage, instance 1 ●●●●
Non-directional earth-fault protection, low stage, instance 1 ●-●-
Non-directional earth-fault protection, high stage, instance 1 ●-●-
Negative-sequence overcurrent protection, instance 1 ●●●●
Three-phase thermal overload protection for power
transformers, two time constants ●●●●
Circuit breaker failure protection ●●●●
LV-side protection
Three-phase non-directional overcurrent protection, low
stage, instance 2 ●●●●
Three-phase non-directional overcurrent protection, high
stage, instance 2 ●●●●
Three-phase non-directional overcurrent protection,
instantaneous stage, instance 2 ●●●●
Non-directional earth-fault protection, low stage, instance 2 - ●-●
Non-directional earth-fault protection, high stage, instance 2 - ●-●
Negative-sequence overcurrent protection, instance 2 ●●●●
Arc protection, instance 1 o o o o
Arc protection, instance 2 o o o o
Transformer Protection and Control 1MRS756891 B
RET615
Product version: 2.0 Issued: 01.10.2009
4 ABB

Table 2. Supported functions, continued
Functionality A B C D
Arc protection, instance 3 o o o o
Control
Circuit-breaker control with interlocking ●●●●
Disconnector position indication, instance 1 ●●●●
Disconnector position indication, instance 2 ●●●●
Disconnector position indication, instance 3 ●●●●
Earthing switch indication ●●●●
Tap changer position indication ●●●●
Condition monitoring
Circuit-breaker condition monitoring ●●●●
Trip circuit supervision, instance 1 ●●●●
Trip circuit supervision, instance 2 ●●●●
Measurement
Disturbance recorder ●●●●
Three-phase current measurement, instance 1 (HV side) ●●●●
Three-phase current measurement, instance 2 (LV side) ●●●●
Sequence current measurement (HV side) ●●●●
Residual current measurement, instance 1 (HV side) ●-●-
Residual current measurement, instance 2 (LV side) - ●-●
●= included, o = optional at the time of order
1) Note that all directional protection functions can also be used in non-directional mode.
Transformer Protection and Control 1MRS756891 B
RET615
Product version: 2.0 Issued: 01.10.2009
ABB 5

3. Protections functions
The IED features, three-phase, multi-slope
transformer differential protection with an
instantaneous stage and a stabilized (biased)
stage to provide fast and selective protection
for phase-to-phase, winding interturn and
bushing flash-over faults. Besides second
harmonic restraint an advanced waveform-
based blocking algorithm ensures stability at
transformer energization and a fifth harmonic
restraint function ensures good protection
stability at moderate overexcitation of power
transformers. Sensitive restricted earth-fault
protection (REF) completes the overall
differential protection to detect even single
phase-to-earth faults close to the neutral
earthing point of the transformer. Either the
conventional high-impedance scheme or a
numerical low-impedance scheme can be
selected for protection of the windings. When
the low-impedance REF protection is used
neither stabilizing resistors nor varistors are
needed and as a further benefit the
transforming ratio of the neutral earthing CTs
can differ from those of the phase current
transformers. Due to its unit protection
character and absolute selectivity REF does
not need time grading with other protection
schemes, and therefore high-speed fault
clearance can be achieved.
The IED also incorporates a thermal overload
protection function, which supervises the
thermal stress of the transformer windings to
prevent an accelerated aging of the winding's
insulation. Multiple stages of short-circuit,
phase-overcurrent, negative-phase-sequence
and earth-fault back-up protection are
separately available for both windings. Earth-
fault protection based on the measured or
calculated residual overvoltage is also
available. Finally, the IED also offers circuit-
breaker failure protection.
Enhanced with optional hardware and
software, the IED also features three light
detection channels for arc fault protection of
the circuit breaker, busbar and cable
compartment of metal-enclosed indoor
switchgear.
The arc-fault protection sensor interface is
available on the optional communication
module. Fast tripping increases personal
safety and limits material damage within the
switchgear in an arc fault situation.
Transformer Protection and Control 1MRS756891 B
RET615
Product version: 2.0 Issued: 01.10.2009
6 ABB

GUID-987FF881-286F-44E3-A24B-4A3C2A137C26 V1 EN
Figure 1. Protection function overview of standard configuration A
GUID-E197B2BA-0E91-413E-9462-7E2FEE2D320F V1 EN
Figure 2. Protection function overview of standard configuration B
Transformer Protection and Control 1MRS756891 B
RET615
Product version: 2.0 Issued: 01.10.2009
ABB 7

GUID-A68F1E1E-49FA-4B6C-9F18-1099F998F9EE V1 EN
Figure 3. Protection function overview of standard configuration C
GUID-B23D25EF-1130-4D27-8E46-1F3ADD5851EB V1 EN
Figure 4. Protection function overview of standard configuration D
Transformer Protection and Control 1MRS756891 B
RET615
Product version: 2.0 Issued: 01.10.2009
8 ABB

4. Application
RET615 provides main protection for two-
winding power transformers and power
generator-transformer blocks. As of now,
there are four standard configurations
offering comprehensive protection functions
for detection and elimination of operational
disturbance conditions and power
transformer faults.
The standard configurations A and C are
intended for power transformers with earthed
HV side neutrals. The A configuration
features low impedance REF protection while
the C configuration offers high impedance
REF protection. The B and D configurations
fit transformers with a solidly earthed LV side
neutral or their LV side neutral earthed over a
resistor. The B and D configurations fit also
applications including a separate earthing
transformer located within the area of
protection. The A and B configurations also
suit applications, where the turns ratio of the
CT of the neutral earthing circuit differs from
turns ratio of the line CTs. The C and D
configurations require that the turns ratios of
the CTs are equal.
Transformer Protection and Control 1MRS756891 B
RET615
Product version: 2.0 Issued: 01.10.2009
ABB 9

GUID-AB31C909-F38E-4885-AFEE-E2EEE3675263 V1 EN
Figure 5. Main protection of a Yyn(d) connected power transformer and control of the HV side
circuit breaker using a RET615 with the standard configuration D. Restricted E/F
protection with a high impedance scheme is applied on the transformer MV side. A
REF615 with the standard configuration C is used as redundant back-up protection
on the HV side. In addition, a REF615 with the standard configuration F is used on
the MV side to provide, besides O/C and E/F back-up protection, busbar overvoltage
and undervoltage protection. Further, the REF615 with the standard configuration F
enables local/remote control of the circuit breaker on the MV side.
Transformer Protection and Control 1MRS756891 B
RET615
Product version: 2.0 Issued: 01.10.2009
10 ABB