Utility Distribution Power Quality and Reliability

1
Utility Distribution Power Quality and Reliability

• APQA
• February 23, 2006
• Travis Cunningham

2
Agenda

• SRPs Distribution System Overview
• Fault Protection is its Affects
• Distribution Automation
• Online Switching

3
SRPs Distribution System

• 858,314 electric customers
• 2,900 square mile electric service area
• 168 substations with 308 transformers
• 1146 circuits

4
SRPs Distribution System

• 3700 miles of OH primary distribution
• 12500 miles of UG primary distribution
• 6044 MW peak load

5
SRPs Electric Service Area
6
Distribution Operation Center

• Operate the distribution system
• Driven by reliability
• Reduce outages
• Restore outages as fast as possible

7
Fault Protection

• Fuse
• Substation Breaker
• Recloser
• Vacuum Fault Interrupter (VFI)

8
Substation Breaker
9
Exceptions

• IPACS substation
• Hold tag

10
How does this affect PQ?

• Intermittent power for the customers on the
  faulted circuit
• Voltage sag on neighboring circuits
• Sensitive equipment could trip
• Dimming of lights, etc

11
Distribution Automation (DA)

• Series of switch operations to isolate a fault
  automatically
• Switches communicate on a spread spectrum
  unlicensed radio
• Master control and radio are in the substation

12
Radio Controlled Switch
13
DA Teams
Breaker
Switch
Switch
Breaker
Switch
14
DA Operation
15
DA Operation
16
What does DA mean to PQ?

• Less sustained outages

17
Online Switching

• Moved from wall map to GIS
• Switching program developed in house
• Dynamic view of system

18
DOC
19
Wall Map
20
Online Switching
21
(No Transcript)
22
(No Transcript)
23
(No Transcript)
24
Online Switching Effects

• Better data resulting in better operation
• Switching errors due to misreading the map
  reduced to zero since inception of online
  switching
• Average of past four years 7.5 errors

25
Conclusion

• New technology is being implemented to improve
  reliability

26
Questions
?