Application; Ret650 Application - ABB Relion 650 Series Applications Manual

1MRK 504 124-UEN B
Section 2
2.1

RET650 application

RET650 provides fast and selective protection, monitoring and control for two- and three-
winding transformers, autotransformers, generator-transformer units and shunt reactors. The
transformer IED is designed to operate correctly over a wide frequency range in order to
accommodate power system frequency variations during disturbances and generator start-up
and shut-down.
A very fast differential protection function, with automatic CT ratio matching and vector group
compensation, makes this IED the ideal solution even for the most demanding applications.
Since RET650 has very low requirements on the main CTs, no interposing CTs are required. The
differential protection function is provided with 2nd harmonic and wave-block restraint
features to avoid tripping for magnetizing inrush current, and 5th harmonic restraint to avoid
tripping for overexcitation.
The differential function offers a high sensitivity for low-level internal faults. The unique and
innovative sensitive differential protection feature of the RET650 provides the best possible
coverage for winding internal turn-to-turn faults, based on well-known theory of symmetrical
components .
Low impedance restricted earth-fault protection function are available as complimentary
sensitive and fast main protection against winding earth faults. This function includes a
directional zero-sequence current criterion for additional security.
Tripping from Pressure relief/Buchholz and temperature devices can be done through the
transformer IED where pulsing, lock-out contact output and so on, is performed. The binary
inputs are heavily stabilized against disturbance to prevent incorrect operations at for
example, dc system capacitive discharges or DC earth faults.
Versatile phase, earth, negative and zero sequence overcurrent functions, which can be made
directional, provide further alternative backup protection. Thermal overload with two time-
constants, volts per hertz, over/under voltage are also available.
A built-in disturbance and event recorders provide valuable data to the user about status and
operation for post-fault disturbance analysis.
Breaker failure protection allows high speed back-up tripping of surrounding breakers.
Disturbance recording is available to allow independent post-fault analysis after primary
disturbances.
Four packages have been defined for the following applications:
• Transformer backup protection (A00)
• Two-winding transformer in single breaker arrangements (A01)
• Three-winding transformer in single breaker arrangements (A05)
• Tap changer control (A07)
The packages are configured and ready for direct use. Analog and tripping IO has been pre-
defined for basic use. Other signals need to be applied as required for each application.
The graphical configuration tool ensures simple and fast testing and commissioning.
Transformer protection RET650
Application manual

Application

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Section 2
Application
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