Customer Outages & Emergency Response
Download
Report
Transcript Customer Outages & Emergency Response
Power Quality
Mary Santori, P.E.
Senior Engineer
September 12, 2013
1
Topics discussed
Causes of Disturbances
Normal utility operations that can cause
problems with sensitive equipment
How Xcel Energy works with customers on
power quality issues
Reliability Key Indices and Outage Causes
Preventive Maintenance
2
Causes of disturbances
On-site interference
Caused by loads inside a facility affecting the power in such a way
as to cause other loads to malfunction
Neighboring interference
Caused by loads outside a facility affecting the power in such a
ways as to cause other loads to malfunction
Natural phenomena and accidents
Events such as lightning, storms, cars hitting power poles and
dig-ins to underground cable
Utility operations and problems
Normal utility operations or malfunctioning utility equipment
3
Normal utility operations that can cause
problems with sensitive equipment
Protective devices operating under fault (i.e.
breakers, fuses, reclosers)
Normal equipment operation (i.e. capacitor bank
switching)
Single phase events (one phase of a three phase
service is out) – Recommend phase protection
Xcel Energy RMS voltage guideline: + 5% secondary,
+ 10% primary and transmission
4
Typical Electric Utility Distribution Layout
From Transmission System
Breaker
Breaker
Breaker
Breaker
Fuse 1
Feeder A
Fuse 2
Feeder B
XX
Recloser
Customer X
Feeder C
Fuse 3
Fuse 4
Customer Y
Customer Z
Feeder D
5
Typical Electric Utility Capacitor Bank
Switching Waveform at Customer
6
Process for power quality issues
Gather background information from
customer
Try and correlate disturbance to utility
events
Set Recording Meters if Needed
Review Findings and Discuss Mitigations
7
Step 1: Review Issue With Customer
What happened?
Dates and times (important to keep log)
Note anything else that happened in facility at the
same time
Discuss customer’s electrical layout
If customer has monitoring, note location of meters
(service entrance ideal)
8
Step 2: Correlate Disturbance to
Xcel Energy Electrical System
If 0 volt condition, review outage logs
If voltage sag condition, review outages on
transmission system and neighboring taps and
feeders
If voltage sag or surge condition, review
distribution lines device operation (i.e. capacitor
banks and voltage regulators)
9
Step 3: Set Recording Meters if
Needed
Monitor current and voltage at customer’s
transformer or service entrance
Possibly monitor at neighboring customers
10
Step 4: Review Findings and
Discuss Mitigations
After reviewing monitoring data, may need to
repeat Step 2
Note current and voltage relationship
Utility mitigation may include investigating
malfunctioning equipment (cap bank, voltage
regulator, etc..)
Customer mitigation may include installing ride
through equipment, soft start on motors, etc..
11
Reliability Indices Reported to the
MN PUC (many different formats)
SAIFI – System Average Interruption Frequency Index
Total Number of Sustained Customer Interruptions
Total Number of Customers
CAIDI – Customer Average Interruption Duration Index
Total Customer Minutes of Sustained Outages
Total Number of Sustained Customers Interruptions
SAIDI – System Average Interruption Duration Index
Total Customer Minutes of Sustained Outages
Total Number of Customers
MAIFI – Momentary Average Interruption Frequency Index
Total Number of Customer Momentary Interruption Events
Total Number of Customers
12
eg
P
Tr
e
C
ub U a e
n
b
lic k le
D no w
a
C m n
o n ag
In ne e
te ct
nt or
io
A na
n
Li im l
C
gh a
on
tn l
du
in
ct P g
C ol
on e
ta
R ct
O el
S ver ay
Fu pl lo
se ice a d
d U
C G
u
A
Tr r tou
r
an e t
s st
C for er
X ro m
ce ss e
lP a r
r
A lan m
cc n
S ide e d
w n
it c t a
h
In U l
s
S
Im w u l G
p r it ato
op ch r
V
er O
ol
ta F In H
ge us st
a
R e L ll
eg in
Te u k
r m lat
o
C
a p B ina r
ac re to r
ito a k
r e
R Ba r
e n
A clo k
ll s
O e
th r
er
s
V
Customer Minutes
18,000,000
16,000,000
Customer Minutes
Cumulative %
14,000,000
n = 80,714,261
12,000,000
10,000,000
60%
8,000,000
50%
40%
6,000,000
4,000,000
2,000,000
0
Cumulative %
Outages Causes (by customer minutes)
Minnesota
YTD December 2012, Internal Normalization Method
Includes Partial Restoration
100%
90%
80%
70%
30%
20%
10%
0%
13
Preventive Maintenance Efforts
Vegetation Management – Continual Condition Assessment/5-Year
Maintenance Cycle
Infrared Testing – Semiannual Condition Assessment
Substation Transformers
Circuit Breakers
Surge Arrestors
Bushings
Regulators
Animal Control – Ongoing/Condition Based
Capacitor Banks – Annual Condition Assessment (Metro Areas)
Upgrading with Centralized Controls
14
Customer Reliability Opportunities
Customer owned back-up generation
UPS
Auto or Manual Transfer
Phase Loss Protection
Transient Voltage Surge Suppression
15
Power Quality Consultants
(Note: Xcel Energy does not recommend any one
consultant)
EPRI, Mark Stephens, 865-218-8022
Hunt Electric, 651-646-2911
OlympiaTech, 763-559-1900
Parsons Electric, 763-571-8000
ColliSys, 763-535-6000
Hypertect, 651-631-0172
16
17