GE D90 Plus Instruction Manual page 15

CHAPTER 1: GETTING STARTED
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
• Digital fault recorder (DFR).
• Equipment manager.
• Front panel interface (HMI).
These functions operate autonomously from one another. Each function has its own
configuration parameters and each generates it own output signals. All functions share
the hardware and the communications facilities within the device.
The protection function contains the necessary elements required to detect faults in the
power system and send tripping signals to isolate the fault. This will be the primary sub-
system for many users. The protection function also has its own dedicated FlexLogic™
engine which runs at the same scan rate as the protection (16 times per power system
cycle). Protection FlexLogic™ is used to create custom logic schemes for protection
purposes.
Automation is divided into two major sub-groupings: control schemes and automation
logic. Control schemes are hard-coded general purpose schemes responsible for
automatic control within the substation. These include breaker and disconnect switch
control, interlocking, and synchrocheck. Automation logic is intended for development of
custom or advanced automatic schemes in the case the user requires a level of
functionality beyond that found in the hard-coded schemes. Automation logic generally
requires a lower execution rate than protection logic but has greatly expanded
functionality and lines of logic.
The metering function generates a wide range of real-time power system measurements
including voltage, current, frequency, complex power, and energy. It also incorporates a
data logger that provides historical recording of selected metering quantities and includes
statistical (maximum, minimum, and average) and alarming capabilities. The metering
function also provides synchrophasor capabilities in accordance with IEEE C37.118-2005.
The digital fault recorder incorporates transient recorder, disturbance recorder and fault
report capabilities. The transient recorder is intended to capture short events such as a
fault at a high sampling rate (up to 256 samples per cycle). The disturbance recorder
captures longer events such as a power swing at a lower sampling rate. The channel
assignments and triggering of these features can be independently configured. The fault
report facility provides a comprehensive record of the key measurements associated with
an event including fault type, fault location, pre-fault and post-fault quantities, and
clearing time.
The equipment manager function monitors important parameters of the station battery
under normal operation and can be used to detect incipient failures.
Despite their logic separation, signals can be exchanged between these functions. For
instance, it is useful for the digital fault recorder to record the output of protection
functions. Consequently a fixed, pre-determined set of signals is available as inputs to
each function. These are illustrated in the following figure.
Plus
The D90 also includes shared operand functionality. Output signals from the various
functions can be assigned as shared operands available to all functions. These signals can
then be assigned as inputs within other functions.
For example, assume that the
a signal within the automation function. This signal would be assigned as a shared
operand. As such, the
PHASE TOC1 OP
automation function by appearing in the list of available operands.
INTRODUCTION TO THE UR
protection FlexLogic™ operand is required as
PHASE TOC1 OP
operand would subsequently become available to the
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