Automation Features - GE D90 Plus Instruction Manual

DEVICE OVERVIEW
Breaker failure
Multi-breaker configurations
Single-pole tripping

Automation features

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The D90 can be used to carry out fully independent breaker failure protection over the
breakers associated to the line when connected to a substation with a breaker-and-a-half
or ring bus arrangement. The D90
inputs and outputs, and elements to perform two independent breaker failure functions.
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The D90 supports multi-breaker busbar configurations such as breaker-and-a-half or
ring bus arrangements, providing dual breaker autoreclose, dual synchrocheck elements,
and dual independent breaker failure elements.
Figure 9: Breaker-and-a-half configuration example
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The D90 relay uses an advanced phase selection algorithm that provides fast and
accurate fault type identification even under weak-infeed conditions. The pilot schemes
for single pole tripping offer an option to send the permissive/ blocking signal using one,
two or four bits of information. This allows sharing more information between the terminal
relays and improving the accuracy of single-pole tripping on cross-country faults. A
convenient trip function is built-in to coordinate actions of the key elements of the single-
pole tripping package.
A separate automation engine with powerful Boolean and math functions allows the user
to easily engineer complex custom automation schemes. This includes advanced
interlocking schemes, remedial action schemes, and advanced load shedding schemes.
Execution of the automation logic is independent of protection elements and protection
logic. The automation capability is segmented into seven independent modules to simplify
implementation and testing of complex schemes in which each module is independently
editable and password protected. While building and compiling these modules, intelligent
error detection automatically notifies the users of errors such as overflows, type
mismatch, division by zero, and square root of a negative number, allowing the user to
achieve maximum optimization. The programming interface complies with the global
standard IEC 61131 for industrial control programming and also allows for embedded
comments. Easy to use on-line and off-line debugging and simulation tools provide
extensive testing capabilities of complex schemes. This includes forcing of input variables,
simulation of analog values and visualization of live logic states and live analog values.
Synchrocheck and breaker control, disconnect switch control, and local/remote breaker
control are available as hard-coded schemes as part of the D90
capabilities.
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provides the required current source inputs, digital
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D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 2: PRODUCT DESCRIPTION
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automation