| SCADA
for ELECTRICAL
DISTRIBUTION AUTOMATION |
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One
of the ten largest electrical power producers in the United States
recently implemented RealFlex as a key component in its first
distribution automation project.
PROBLEM DESCRIPTION AND SYSTEM REQUIREMENTS:
The firm had been investigating centrally controlled
Distribution Automation (DA) for a number of years. From previous
pilot experiences, the client recognized the traditional "point
to point" wiring between the equipment controller and the RTU
was expensive, difficult to maintain and impossible to migrate
into future technologies. In addition, they were looking for an
inexpensive SCADA solution that would allow:
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Remote monitoring and control
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The ability to address multiple
communications ports with different drivers/protocols
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On-line configuration
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Handling a large number
of points while maintaining realtime performance
They had to find the right combination of SCADA
software, field equipment, system integration, communications and
feeder design to install DA on twenty-three 13kV distribution feeders
with the primary goal of reducing customer outage durations.
REALFLEX SOLUTION:
Utilizing a combination of RealFlex and LanFlex, the
system is monitored and controlled from locations around the state.
Twelve 900 Mhz master radios operating on different licensed frequencies
are installed throughout the service territory to provide coverage.
Utilizing Cooper reclosers (which were chosen after evaluation of
motor operated switches, load interrupters, reclosers and sectionalizers),
faults are isolated and power re-routed, restoration is controlled
by the RealFlex operator.
With cooperation from Cooper and Motorola, the client was able to
integrate the Cooper 4C/LS controller with the Motorola MOSCAD RTU
utiizing protocol transmission software. This software, which resides
on the MOSCAD RTU, polls the 4C/LS controller in PGE-2179 protocol,
recognizes exceptions and translates them into Motorola's MDLC protocol
for transmission through the 900 Mhz system back to the RealFlex
server. RealFlex accesses the data utilizing a MODBUS protocol scanner
that was customized for the MOSCAD RTU interface. The system allows
remote personnel to monitor over 9000 points. Control Sequence Language
(CSL) is used to automatically test radio batteries and other field
equipment. Hot Standby with Automatic Failover insures redundancy
at the SCADA master station.
RESULTS:
The client has an extremely inexpensive system
that is maintained by operators. Field personnel are able to send
controls and make adjustments to the system remotely. Customer outage
duration rarely lasts longer than 5 minutes and is often avoided
completely, thanks to the Distribution Automation System.
REALFLEX SYSTEMS SOFTWARE:
RealFlex, LanFlex, CSL, Hot Standby with Automatic
Failover, MOSCAD I/O Driver
DATABASE SIZE:
9500 points
PC HARDWARE:
Various computers
I/O HARDWARE:
Motorola MOSCAD RTUs, Cooper Type VSA recloser, 900
Mhz radio communications
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