Automation Features - GE D90 Plus Instruction Manual

CHAPTER 2: PRODUCT DESCRIPTION
Single-pole tripping

Automation features

Synchronism check
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
Figure 10: Breaker-and-a-half configuration example
Plus
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.
For additional information, refer to:
Automation specifications
Automation on page 429
The synchrocheck elements are typically used at locations where the two parts of the
system are interconnected through at least one other point in the system, which are to be
joined by the closure of one or more circuit breakers. The D90
voltage source inputs, digital inputs and outputs, and elements to monitor differences in
voltage magnitudes, phase angles, and frequencies to perform synchronism check across
Plus
two breakers. The D90 can be used to carry out full independent control over the
breakers associated to the line when connected to a substation with a breaker-and-a-half
or ring bus arrangement.
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DEVICE OVERVIEW
Plus
automation
Plus
provides the required
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