distribution automation: fault detection, isolation, and restoration jeremy blair, p.e....
TRANSCRIPT
Distribution Automation: Fault Detection, Isolation, and Restoration
Jeremy Blair, [email protected]
8/31/2012
The Evolution of Sectionalization
Feeder Breaker
Feeder Breaker
R
R
Install Fuses to reduce Exposure to Trunk
New Radial Breakers reduce Trunk Line Mile Exposure and Customer Count risk
Radial Recloser reduces Trunk Line Mile Exposure and Customer Count risk. ~25% reduction in Breaker CI.
Tie Recloser can reduce breaker CI by another 25%!
FDIR Basics• FDIR = Fault Detection Isolation Restoration• Automatically:– Isolates faulted line sections– Switches to restore power to unfaulted sections
• Makes decisions using– Overcurrent/reclosing – Loss of Voltage (any phase typical)– Loading prior to outage (typically)– Preset capacity limits (typically)– What the other switches see (typically)
• Does not typically LOCATE fault.
• Switching Equipment & Coordination (Motor Operated Switchgear, Reclosers, etc.)
Variations & Considerations for FDIR Systems
Equipment Assessment for Cost Effective FDIR systems
Equipment Environmental Regular Maintenance
Mechanical Speed
Interrupt Requirements
Motor Operated Switches
Corrosion, Ice loading
-Motor Operator-Mechanism
-Blades
Seconds Load Break
Enclosed / Padmounted Switchgear
Enclosed Mechanism
-Motor Operator Seconds Load Break
Electronic Sectionalizer
Enclosed Mechanism
-Batteries Cycles Load Break
ElectronicRecloser
Enclosed Mechanism
-Batteries Cycles Fault Break
• Switching Equipment & Coordination (Motor Operated Switchgear, Reclosers, etc.)
• Logic Architecture (Centralized, Distributed)
Variations & Considerations for FDIR Systems
• Distributed logic provides:– SCADA independence– Ability for targeted deployments of switching and telecom equipment– Avoid single points of failure without redundancy
• Centralized logic provides:– One time large investment with low cost scalability– Possibility for FDIR as a SCADA/OMS add-on– Possibility for centralized support/programming– Ease of system visibility within logic (capacity, multiple sources,
multiple contingencies)• Hybrid systems
– Centralized logic on localized controllers like RTU’s or compact hardened computers.
– Can be distributed to whatever level necessary…regional SCADA host, substation, switch controller
Logic Architecture for FDIR systems
• Switching Equipment & Coordination (Motor Operated Switchgear, Reclosers, etc.)
• Logic Architecture (Centralized, Distributed)• Communication
– Centralized, Peer-Peer, None– IP, serial– Public, Private– Licensed Wireless, Unlicensed Wireless, Fiber, Copper
Variations & Considerations for FDIR Systems
• Switching Equipment & Coordination (Motor Operated Switchgear, Reclosers, etc.)
• Logic Architecture (Centralized, Distributed)• Communication
– Centralized, Peer-Peer, None– IP, serial– Public, Private– Licensed Wireless, Unlicensed Wireless, Fiber, Copper
• Deployment (Targeted, Risk-based, Systemwide)– Utility Footprint– Known Exposure zones– Regulatory cooperation– Operating rules (safety, capacity risk, switching procedures, etc.)
Variations & Considerations for FDIR Systems
Value of Radial Sectionalization vs. FDIR assuming even customer & fault distribution
Feeder Breaker
Feeder Breaker
RCust/2 Cust/2
Miles/2Miles/2
Sectionalization Risk Reduction= 1-{[(Cust/2)(Miles/2) + (Cust/2)(Miles)]/(Cust*Miles)}-for the cost of 1 Recloser per feeder: 25% CIAV
R
RCust/2 Cust/2
Miles/2Miles/2
2-way Transfer Risk Reduction= 1-{[(Cust/2)(Miles/2) + (Cust/2)(Miles/2)]/(Cust*Miles)}-for the cost of 1.5 Reclosers per feeder: 50% CIAV
1-way Transfer Risk Reduction= 1-{[(Cust/2)(Miles/2) + (Cust/2)(Miles/2)]/(Cust*Miles)}-for the cost of 2 Reclosers per feeder: 50% CIAV
Maximizing FDIR EffectivenessTargeted deployments based on historical feeder performance
can be deployed anywhere
Urban– High CIAV opportunity– Capacity Limits with full
visibility allow for use of multiple sources
– Scalability– Can use meshing or
short range comm’s
Rural– High CMAV opportunity– Capacity limits allow for
load or voltage constrained installations
– Distance & vegetation may require point to point, low throughput comm’s
Maximizing FDIR Value• Optimal Configuration– 3 breaker, 2-way default = 50% CI reduction on two feeders– Case by case:
• Goal is lowest $/CIAV and highest Customer Inclusion • More than two sources not beneficial (high $/CIAV) unless needed
for capacity/visibility• Value of automation on second feeder• Customer & Exposure Distribution
– Use of existing equipment provides low $/CIAV opportunities
– Use of capacity limits allow beneficial installation of FDIR systems in more scenarios.
Capacity considerations for FDIR systems
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
90.00%
100.00%
1 483 965 1447 1929 2411 2893 3375 3857 4339 4821 5303 5785 6267 6749 7231 7713 8195
Pe
rce
nt
of
Pe
ak
Lo
ad
# of Hours
2011 Hourly Peak Average Loading CurveGSU-TX
90% of hoursat or below70% of peak
-Equipment/System Intelligence:-Entergy’s 70-90 rule-Visibility to support Capacity Limitations-Prevent or limit scope of transfer
FDIR Program Value: Real Entergy Numbers
• 117 Automated Load Transfer (ALT) systems in service at 2011YE– 265 individual switches installed– $13.25M in installed equipment
• 108,000 CI & 13,000,000 CM saved in 2011 – ~$123/CIAV annually for one year program value– ~$31/CIAV annually for four years program value
• Little maintenance required using magnetically actuated vacuum bottle switches & reclosers, so value grows with time!
