distribution automation plans in aep texas. overview aep texas is deploying smart meters to roughly...
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Distribution Automation Plans in AEP Texas
Overview
AEP Texas is deploying smart meters to roughly 1,000,000 customers
The meters utilize Landis + Gyr UtiliNet radio technology
UtiliNet mesh network requires regular placement of routers on utility poles throughout the system
Routers can be used for more than strictly AMI traffic If they’re there, why not use them?
Very limited in scale and scope so far
Deployment
Total of twelve smart switches deployed so far Installed in sets of three Locations: Two sets in San Angelo, one set in Abilene,
and one set in Corpus Up to ten additional locations (30 additional smart
switches) may be chosen before the end of 2011. They will most likely be deployed in the Rio Grande Valley, Corpus Christi, Laredo, Victoria, Abilene, and/or San Angelo.
Organizational Responsibilities
Reliability Engineering: Selects location, performs studies as necessary, program the devices
AMI construction group: Installs routers for AMI deployment
Information Technology: Creates the links between the UtiliNet system and SCADA
Dispatch: Operates and monitors the status of the devices
Switch Specification
Using S&C IntelliRupter 15.5kV models to support our mostly 7.2/12.47kV
system Interrupting rating: 12500A Continuous current rating: 630A Uses “pulse closing” technique
Standard reclosing could be used for fuse saving strategies, but we’ve opted not to use it
Ensures less damage to distribution equipment by limiting the amount of energy in a fault
Switch Specification (cont’d)
Modular communications Vendor installs Landis + Gyr UtiliNet module SpeedNet and other radios available and possible for
future use Communications infrastructure
UtiliNet mesh network Very scalable, but not very high bandwidth DA takes much higher priority in signals than AMI Proprietary UtiliNet signals converted at station to
DNP3 for SCADA master control device Latency is expected to be measured in seconds as
opposed to milliseconds or minutes
Mounting/Installation
Switches are mounted on 45 ft, Class 3 or better poles
Only overhead installations on wood poles so far
No location restrictions beyond engineering judgment Everybody knows of the story of the switch right
next to a drainage ditch… AMI routers must generally be installed in an
area before DA schemes are installed
Maintenance
S&C IntelliRupters have a life span of about 30 years or more
Batteries should be replaced on a 5 year cycle
Bypass switches are installed on both load and source side
Thus far, testing is performed live Modular communications and control module
Control module can be accessed via Wi-Fi for programming and to check error logs
AMI Integration
Leaning heavily on AMI communications system Communications to the substation shares routers
and protocols with AMI system DA gets top priority in communications along mesh At the station, switch signals are translated to DNP3
and sent to the SCADA master control device Switches do not communicate directly with meters
UtiliNet mesh latency would be too high for something like this to work
Safety
For loop-automation, the “middle” device must be placed into non-reclose mode before work begins A non-reclose order or hot line tag may be used
on the source side device as well The S&C IntelliRupter has an interlocking
visual open To accommodate contractors/out-of-town
crews, dispatchers will let crews know they are on an automated system when they logon
Operations
Real-time visual representations of the status of the devices (open/closed/non-reclose/etc) are provided via SCADA Also allows remote control of functions – can be
overridden by field using physical levers Non-switch smart nodes (such as intelligent
volt-var controls) are not anticipated at this time
Operations (cont’d)
Alarm points are used on abnormal switch state Outage tickets are still manually generated by
dispatchers Switches can be used to gather outage
information, isolate faults, and re-energize the line – similar to breakers using SCADA
Due to the limited scope of deployment, switches will only be marginally useful in load estimation and planning functions
Budgeting/Cost Recovery
Costs of systems is broadly imbedded in rates until a more timely recovery mechanism is in place
Limited scope of projects means no special projects have been created; they are lumped in with general sectionalizing and reliability budgets
AMI communication devices (routers) are paid for by smart meter surcharge, and AMI remains their primary function DA is along for the ride!
One Caveat
Some of the equipment may not stand up to highly corrosive environments…. Installation was on North
Padre Island, only a few months old
ALL future installations will use our own external disconnects
Questions?