1
Seminar at Case Western Reserve University, September 29, 2014
SSmartt Distribution
Di t ib ti Systems:
S t
State‐of‐the‐Art and the Future
Chen‐Ching Liu
Boeing Distinguished Professor
Washington State University
(Also Professor,
Professor University College Dublin)
Research Sponsored by PNNL and Dept of Energy
2
Smart Grid
Source: http://energy.gov/sites/prod/files/oeprod/DocumentsandMedia/Arshad_Mansoor.pdf
3
US Smart Grid Investment Grants (SGIGs)
Federal SGIG Expenditures versus Plan
•
•
•
Total SGIG Expenditures by Type of Project
Including the investments made by the recipients, the combined level of federal and
recipient investment totals about $4
$4.6
6 billion
billion, through March 31
31, 2012
ETS projects have installed more than 287 networked PMUs and a total of at least 800
networked PMUs will be installed at completion.
AMI projects installed 10.8 million smart meters now and it will install up to 65 million
smart meters by
b 2015.
Source: http://energy.gov/sites/prod/files/Smart%20Grid%20Investment%20Grant%20Program%20-%20Progress%20Report%20July%202012.pdf
4
Benefits of SGIGs
Highlights
•
•
•
Electric Power Board of Chattanooga (EPB) is installing 1,500 automated circuit switches
and sensors on 164 circuits. When 9 tornados ripped through communities in April of 2011,
early in the project’s installation schedule, EPB used 123 smart switches that were in service
to re‐route power, avoiding 250 truck rolls and saving customers thousands of hours of
outage time.
Talquin Electric Cooperative (TEC) in northern Florida deployed smart meters that have
already produced annual savings of more than $500,000 by avoiding more than 13,000
truck rolls for service connections and disconnections and non‐payment problems. The
system also improves outage management and enables TEC to send repair crews to the
precise locations where faults occurred.
Western Electricity Coordinating Council (WECC) synchrophasor project involves 18
transmission owners in 14 states and is installing 341 PMUs and 62 phasor data
concentrators (PDC). WECC estimates that the application of these devices will enable ~100
100
MWs additional capacity on the California‐Oregon intertie.
Source: http://energy.gov/sites/prod/files/Smart%20Grid%20Investment%20Grant%20Program%20-%20Progress%20Report%20July%202012.pdf
5
SGIGs on Distribution Automation
•
EDS involves deployment of technologies and systems for improving distribution system
operations, including: (1) outage management with devices such as automated circuit
switches and reclosers, and (2) voltage/volt‐ampere reactive (VAR) control with field
devices such as automated capacitors, voltage regulators, and voltage sensors.
Installed SGIG Automated Switches
Avista Utilities,
Utilities WA
Spokane and Pullman
((WSU)) Smart Circuit
Installed SGIG Automated Capacitors
Project Cost: $40M
Fed Funding: $20M
Source: http://energy.gov/sites/prod/files/Smart%20Grid%20Investment%20Grant%20Program%20-%20Progress%20Report%20July%202012.pdf
6
SGIG Advanced Metering Infrastructure
•
AMI involves deployment of smart meters; communications networks to transmit data from
the meters at 15, 30, or 60 minute intervals; and meter data management systems to
receive,, store,, and process
p
data from the meters. These projects
p j
use smart meters to collect
interval load data, while some projects also use smart meters to collect data on voltages
and power quality.
SGIG Smart Meter Deployment
SGIG AMI Project Expenditures on
Technologies and Systems
Source: http://energy.gov/sites/prod/files/Smart%20Grid%20Investment%20Grant%20Program%20-%20Progress%20Report%20July%202012.pdf
7
Reliability Improvements
•
•
48 SGIGs are applying DA technologies to improve reliability:
42 deploying automated feeder switches (1 to > 1000’s of switches)
–
•
System integration schemes (AMI/OMS/DMS/SCADA/GIS)
–
–
–
•
Enables fault location,, isolation and service restoration functions
26 projects are applying distribution management systems
36 implementing AMI outage notification
22 deploying equipment health sensors
Initial results from 4 Projects (1,250 feeders) ‐ April 1, 2011 through March 31, 2012
Source: http://tcipg.org/sites/tcipg.org/files/slides/2013_02-01_Arnold.pdf
8
Distribution System Restoration (DSR)
• A smart grid application and an important objective of
distribution automation.
automation
• Restore critical load during extreme events.
• A typical multi‐objective, combinatorial problem with
constraints, including topological and electrical constraints.
Restore
R
t
loads
l d in
i a secure andd
efficient manner
Selecting and sequencing
a set of switching
operations
ti
Reduce the duration of
outages and improve
reliability
Distribution
System
Restoration
9
Basic DSR Strategies
Strategies*
Single
Single & level‐2
Double
Triple
Double & level‐2
Self
*KEPCO: Intelligent DA System
10
DSR Algorithm: Spanning Tree Search*
Search
• Restore maximum amount of load with the minimum number of switching operation.
*
J. Li, X.-Y. Ma, C.-C. Liu, and K. P. Schneider, "Distribution system restoration with microgrids using spanning tree
search," IEEE Trans. Power Syst., Available online: http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=06781027
11
Example – PNNL Test System
Z15
Z28
Z25
Z29
Z31
F-a
Z1
Z24
Z22
Z4
Z17
Z35
Z30
Z8
Z18
Z5
Z23
Z20
Z39
Z6
Z7
Z38
Z19
Z2
Z14
Z16
Z9
Z40
Z33
Z12
Z3
Z10
Z13
Z26
Z27
Z66
Z67
•
FB-a
Z34
Z21
Z32
Z36
Z11
T1
Z41
Z64
Z62
Z44
Z65
Z69
Z71
F-b
Z55
Z68
Z37
Z57
Z75
Z48
Z70
Z58
T2
Z45
Z63
Z60
Z79
Z46
Z47
Z78
Z59
Z42
Z54
Z49
Z56
Z80
Z73
Z52
Z43
Z50
FB-b
Z74
Z61
T3
Z72
Z76
Z51
Z53
T7
SubTransmission
Node
F-c
Z81
Z104
Z102
Z84
Z116
Z115
Z110
Z88
Z98
Z97
Z85
T6
Z113
Z105
Z109
Z111
Z95
Z108
Z77
S
Z103
Z100
Z119
Z86
Z87
Z83 Z93
Z118
Z99
Z82
Z94
Z96
FB-c
Z114
Z90
Z92
Z112
Z101
Z89
Z106 Z107
•
•
Taxonomy “R3-12.47-2” is a
prototypical unbalanced
distribution feeder model for
moderate urban areas, which
is developed by Pacific
Northwest National
Laboratory (PNNL).*
A fault occurs at zone Z110.
Triple grouping restoration
Z91
Z120
Z117
Fd
F-d
Z121
Z144
Z142
Z135
Z148
T4
Z149
Z145
T5
Z151
Z156
Z137
Z140
Z159
Z124 Z150
Z128 Z138
Z125 Z143
Z126
Z127 Z139
Z141
Z155
Z152
Z153
Z123
Z158
Z122
Z134
Z136 Z129
Z130
Z146 Z147
FB-d
Z154
Z160
Z132 Z131 Z133
Z157
Voltage Regulator
*
F-a Feeder Id
Load Zone
Feeder Breaker
Sectionalizing Switch
Tie/Microgrid Switch
Restoration Scheme
•Open: 90-92,
90-92 96-89
•Close: 88-156(T4), 136120(T5), 45-90(T3)
K. P. Schneider, Y. Chen, D. Engle, and D. Chassin, "A Taxonomy of North American Radial Distribution Feeders,“
Proc. IEEE PES Gen. Meet., 2009, pp. 1-6.
12
Distribution Automation (DA)
• Distribution Management System (DMS) provides
SCADA functions and other distribution system
applications such as feeder restoration.
Functions
• Fault detection
• Trouble call analysis
• Network reconfiguration
and restoration
• Alarm processing
• Voltage / VAR Control
• Remote monitoring and control
User Interface
Mi i M
Mini-Map
M i i & Control
Monitoring
C
l
Alarm
Operation
p
historyy
Equipment Information
GIS Map
Switch & Line Symbol
y
This MMI software was developed by and used in KEPCO (Korean power utility)
Feeder RTU
LBS
FRTU
Feeder RTU
RTU
Controller
Modem Space
p
Battery (24V)
Transformer
Power / Control
Receptacle
p
This feeder RTU is manufactured by pnctech
http://www.pnctech.co.kr
16
Service Restoration with DA (1)
(1)*
1. Fault occurs
2. Open CB
3. Find fault
4. Isolation
*KEPCO: Intelligent DA System
17
Service Restoration with DA (2)
(2)*
5. Transfer outage area
6. Execute restoration plan
7. Field crew
*KEPCO: Intelligent DA System
18
Self‐Healing
Self
Healing Technology
Conventional Restoration
Self-Healing Restoration
F3
F5
F3
F5
F6
F6
F9
Peer to peer communication
F2
Fault Current
F2
Fault Current
F10
DMS
Control Center
F7
F8
F9
F10
DMS
Control Center
F7
F4
F8
F4
• Fault isolation: Manual switching
• Fault isolation: Automatic switching
• Restoration time: Minutes to hours
• Restoration time: Seconds to minutes
• Outage duration: Long
• Outage duration: Short
• Customer costs: High
• Customer costs: Low
19
Restoration
Fault detection
MAS based Service Restoration
Lim, I.-H.; Sidhu, T.S.; Choi, M.-S.; Lee, S.-J.; Hong, S.; Lim, S.-I.; Lee, S.-W., "Design and Implementation of Multiagent-Based Distributed Restoration System in DAS," Power Delivery, IEEE
Transactions on , vol.28, no.2, pp.585,593, April 2013
20
Resilience
• Resilience: “..ability to prepare for and adapt to changing
conditions
diti
and
d withstand
ith t d and
d recover rapidly
idl from
f
di
disruptions..”*
ti
”*
• For distribution systems, resilience means the ability to withstand
Blackout in Manhattan caused by Sandy
major
j disturbances.
– Natural disasters: Earthquake,
tsunami, hurricane, flood, forest
fire ice storm
fire,
storm, etc.
etc
– Major events:
• Superstorm Sandy, US, 2012
• East Japan earthquake, March 11, 2011
• Ice storm in Québec, Canada, 1998
*
Source: Beth Buczynski, “What Hurricane Sandy Taught Us About
America's Crumbling Infrastructure”, http://inhabitat.com/whathurricane-sandy-taught-us-about-americas-crumbling-infrastructure/
Presidential
id i l Policy
li Directive
i i 21 – Critical
i i l Infrastructure Security
i andd Resilience
ili
[Online].
li
Available:
il bl http://www.whitehouse.gov/theh //
hi h
/h
press-office/2013/02/12/presidential-policy-directive-critical-infrastructure-security-and-resil
21
Enhancing resilience in Distribution Systems
• Nearly 90% of power outages occur in distribution systems.*
• Natural disasters cause large‐area
large area and extended outages for
electricity services, resulting in huge losses.
Downed utility poles and wires after hurricane
Source: Rebecca Smith, “Getting 'Smart' on Outages”,
http://online.wsj.com/news/articles/SB100014240529702047554045781
01591971017814
*
Power poles pulled down by ice storms
Source: “Thousands in the dark after ice storms cut power lines in US, Canada”,
http://eyebuster.com/thousands-in-the-dark-after-ice-storms-cut-power-lines-inus-canada/
H. Farhangi, “The path of the smart grid,” IEEE Power & Energy Magazine, vol. 8, no. 1, pp. 18-28, Jan. 2010.
22
Damages to Distribution Grids by
Superstorm Sandy
Downed power lines and other debris litter the streets of Seaside
Heights, N.J., on 31 October 2012, two days after Superstorm
Sandy made landfall in the US.*
The storm surge that accompanied Superstorm Sandy sent water
rushing through the streets near a substation in Brooklyn, N.Y.
Restoring a flooded substation takes much longer than restoring
a downed power line because of the large amounts of water, rust,
and mud left trapped in the structure.*
* Source: Nicholas C. Abi-Samra, “One Year Later: Superstorm Sandy Underscores Need for a Resilient Grid”, IEEE Spectrum,
http://spectrum.ieee.org/energy/the-smarter-grid/one-year-later-superstorm-sandy-underscores-need-for-a-resilient-grid
23
Differences Between Typical Outages and
Catastrophic Outages Due to Extreme Events
Typical Outages
Catastrophic Outages
• Single fault: In most cases, there is only • Multiple faults: Multiple electrical
one faulted component.
facilities are damaged.
• Small amount of load and a small
number of customers are involved.
• Large amount of load and a large
number of customers are out of
services.
• Power is available: Most power
• Lack of power: Power sources can not
sources are working and stay connected.
access the load or are out of service.
• T&D network remains intact: Outage
loads are easily connected to sources.
• T&D network damaged: Overhead
lines, transformers, substations are
damaged.
• Easy to repair and restore
• Difficult to repair and restore
24
Approaches to Resilient Distribution Systems*
Systems
• Construction
– Improving design and construction standards, overhead distribution
reinforcement, undergrounding, etc.
• Maintenance
– Online temperature monitoring, power system assessment, thermal
imaging, vegetation management, etc.
• Design and Operation – Smart Grid Techniques
–
–
–
–
–
–
FFault
l LLocation,
i
IIsolation,
l i
and
d Service
S i Restoration
R
i (FLISR)
Integrated Distribution Management System (IDMS)
Advanced Metering Infrastructure (AMI)
Advanced Control and Communication System
Distribution Operation Training Simulator
Microgrids
*
G. Davis, A. F. Snyder, and J. Mader, "The future of Distribution System Resiliency," 2014 Clemson University
Power Systems Conference (PSC), pp. 1-8, Mar. 2014.
25
Smart Grid Technique (3)
Microgrids
• Consisting of DERs, storage, and controllable load
• Grid‐connected and islanded modes
• Microgrids
Mi
id enhance
h
resilience
ili
off di
distribution
t ib ti systems
t
i two
in
t
ways:
– Providing reliable electricity supply for critical loads within microgrids.*
– Supporting outage load recovery of distribution systems.**
* C. Abbey, D. Cornforth, N. Hatziargyriou, K. Hirose, A. Kwasinski, E. Kyriakides, G. Platt, L. Reyes, and S. Suryanarayanan, “Powering
through the storm,” IEEE Power & Energy Magazine, vol. 12, no. 3, pp. 67-76, May 2014.
** J. Li, X.-Y. Ma, C.-C. Liu, and K. P. Schneider, "Distribution system restoration with microgrids using spanning tree search," IEEE Trans.
Power Syst., Available online: http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=06781027.
26
Example – Microgrid Provides Reliable
Electrical Supply to Critical Loads
• A microgrid installed in Sendai, Japan*
Japan
•
•
•
•
East Japan earthquake, March 11, 2011
Accident at the Fukushima #1 nuclear power plant
Power generators used to power university hospitals and
welfare facilities.
The supply of high-quality power such as dc and
uninterruptible ac to load continued without interruption
even immediately after power was lost to the rest of Sendai.
Source: Marianne Lavelle, “Japan
Battles to Avert Nuclear Power
Plant Disaster”,
http://news.nationalgeographic.com
/news/energy/2011/03/110314j
japan-nuclear-power-plant-disaster/
l
l t di t /
*
C. Abbey, D. Cornforth, N. Hatziargyriou, K. Hirose, A. Kwasinski, E. Kyriakides, G. Platt, L. Reyes, and S. Suryanarayanan,
“Powering through the storm,” IEEE Power & Energy Magazine, vol. 12, no. 3, pp. 67-76, May 2014.
27
Example (2) – Microgrid Supports Fast
Recovery of Distribution Systems
• One‐line diagram of Pullman‐WSU System
29
13
1
4
SPU121 48
34
37
(Root)
7
35
30
41
32
12
39
49
14
City Hall
& Police
Station
43
21
22
15
16
23
24
27
25
26
SPU122
5
40
SPU123
Hospital
3
18
31
36
42
SPU124
6
8
10
51
11
SPU125 52
G3 2.1 MW
G2 1.1 MW
38
50
9
17
20
19
G1 1.1 MW
2
SPU Substation
46
45
33
44
47
28
WSU Microgrid
Load Sections
Normally Closed Switch
Normally Open Switch
28
Example (2) – Microgrid Supports Fast
Recovery of Distribution Systems (Conti.)
• Scenario Description
– A severe event happened in the South Pullman 115kV
Substation.
Substation
– As a result, all 5 feeders served by the substation are out
of service.
• Feeders: SPU121, SPU122, SPU123, SPU124, SPU125
• Critical loads: Hospital, City Hall, Courthouse and Police Station
– No source in the Avista system can be used for restoration.
restoration
– WSU generators will be used to restore critical loads.
29
Example (2) – Microgrid Supports Fast
Recovery of Distribution Systems (Conti.)
• Spanning Tree Search algorithm is applied to find the
restoration paths from DERs to critical loads.
29
SPU121
13
48
34
37
35
30
41
32
39
SPU122
SPU123
14
49
10
22
15
16
17
36
23
24
27
25
26
G3 2.1 MW
G2 1.1 MW
38
50
51
21
18
31
Hospital
SPU124
City Hall
& Police
Station
43
40
9
Critical Load
42
Critical Load
20
19
G1 1.1
1 1 MW
Source
SPU125
11
52
46
45
33
44
47
28
WSU Mi
Microgrid
id
30
Example (2) – Microgrid Supports Fast
Recovery of Distribution Systems (Conti.)
• Restoration Path:
G3 17  19  20  34  37  41  32  39  42  36  38  40
City Hall, Courthouse, Police Station
29
SPU121
13
48
34
37
35
30
41
32
39
SPU122
SPU123
14
49
43
40
9
SPU125
10
51
11
52
22
15
16
17
18
31
36
45
33
24
27
G3, a diesel ggenerator, is
used to pick up critical
loads, i.e., City Hall,
Courthouse, Police
Station and Hospital.
G3 2.1 MW
42
20
46
23
G2 1.1 MW
38
50
Hospital
SPU124
City Hall,
Courthouse
& Police
Station
21
44
47
19
G1 1.1 MW
28
Hospital
25
26
WSU Microgrid
31
Example (2) – Microgrid Supports Fast
Recovery of Distribution Systems (Conti.)
• Validation by GridLAB‐D
GridLAB D Power Flow
G3 17  19  20  34  37  41  32  39  42  36  38  40
City Hall, Courthouse, Police Station
Hospital
32
Microgrids Enhance Restoration Capability
• Generation resources and control capabilities of
microgrids enhance fast recovery of distribution systems.
• Grid‐connected mode and
i l d mode.
isolated
d
• When a blackout occurs,
Mi
Microgrid
id
microgrids
i
id can be
b controlled
t ll d
to provide an efficient DSR
strategy to reduce the
restoration time of the
Restoration schemes considering
distribution system.
DERs and Microgrids
g
33
Integrate Microgrids into DSR Algorithm
• Microgrids are modeled as virtual feeders
• Generation limits of DERs are formulated as electrical
constraints of the distribution feeders.
• The island configuration
Microgrid
Virtual Feeder
9
14 15 16 17 18
7
F2
8
F3
of the microgrid
g can be
13
19
modeled as a supplemental 1 2 6
23
20
F4
5
21
topology constraint of the
12
22
4
F5
d
distribution
b
system.
11 10
3
F1
Load Node
Closed Switch
(branch)
Open Switch
(branch)
34
PNNL Test System With Microgrids
Z15
Z28
Z31
F-aa
F
Z1
Z24
Z22
Z4
Z30
Z8
Z18
Z40
Z33
Z12
Z3
M
Z17
Z35
Microgrid 1
Z25
Z29
Z20
Z5
Z23
Z6
Z39
Z7
Z38
Z19
Z2
Z14
Z16
Z9
Z13
Z10
Z26
Z27
FB-a
Z34
Z21
Z32
Z36
Z11
T1
Z71
F-b
Z41
Z64
Z62
Z55
Z68
Z37
Z75
Z44
Z70
Z48
Z58
Z69
Z65
Z57
Z60
Z45
Z63
Z46
M
Z79
Z47
Microgrid 2
T2
Z78
Z59
Z42
Z54
Z49
Z56
Z80
Z73
Z52
Z43
Z50
Z66
Z67
FB-b
Z74
Z61
T3
Z72
Z76
Z51
Z53
T7
S
SubTransmission
Node
Z81
Z104
Z102
Z116
Z115
Z111
F-c
Z95
Z108
Z77
Z110
Z84
Z88
Z98
Z97
Z100
Z119
Z86
Z87
Z85
T6
M
Z103
Z83 Z93
Z118
Z99
Z82
Z94
Z96
FB-c
Z114
Z89
Z92
Z112
Z101
Microgrid 3
Z113
Z109
Z105
Z90
Z106 Z107
Z91
Z120
Z117
Z151
F-d
Z121
Z144
Z142
Z135
Z148
T4
Z156
Z149
Z145
Z137
Z140
Z124 Z150
Z128 Z138
Z125 Z143
Z141
Z155
Z152
Z126
T5
Z159
Z127 Z139
Z153
Z123
Z158
Z122
Z134
Z136 Z129
Z130
Z146 Z147
FB-d
Z154
Microgrid 4
M
Z160
Z132 Z131 Z133
Z157
Voltage Regulator
F-a Feeder Id
Load Zone
Feeder Breaker
Sectionalizing Switch
Tie/Microgrid Switch
M Microgrid
35
Example
• A fault occurs at zone Z43
Z15
Z28
Z29
Z31
F-a
Z1
Z24
Z22
Z4
Z30
Z8
Z18
Z40
Z33
Z12
Z3
M
Z17
Z35
Microgrid 1
Z25
Z20
Z5
Z23
Z6
Z39
Z7
Z38
Z19
Z2
Z14
Z16
Z9
Z13
Z10
Z26
Z27
FB-a
Z34
Z21
Z32
Z36
Z11
T1
Z71
F-b
Z41
Z64
Z62
Z55
Z68
Z37
Z75
Z44
Z70
Z48
Z58
Z69
Z65
Z57
Z60
Z79
Z46
Z47
Z45
Z63
Microgrid 2
T2
M
Z78
Z59
Z42
Z54
Z49
Z56
Z80
Z73
Z52
Z43
Z50
Z66
Restoration Scheme
•Close: 73-Microgrid 2
Z67
FB-b
Z74
Z61
T3
Z72
Z76
Z51
Z53
T7
SubTransmission
Node
Z95
Z108
Z77
S
T6
Microgrid 3
Z113
Z109
Z105
Z97
Z100
Z119
Z86
Z87
M
Z111
F-c
Z81
Z104
Z102
Z116
Z115
Z110
Z84
Z88
Z98
Z85
Z103
Z83 Z93
Z118
Z99
Z82
Z94
Z96
FB-c
Z114
Z92
Z112
Z101
Z89
Z90
Z106 Z107
Z91
Z120
Z117
T4
Z149
F-d
Z121
Z144
Z142
Z135
Z148
T5
Z145
Z151
Z156
Z137
Z140
Z159
Z124 Z150
Z128 Z138
Z125 Z143
Z126
Z127 Z139
Z141
Z155
Z152
Z153
Z123
Z158
Z122
Z134
Z136 Z129
Z130
Z146 Z147
FB-d
Z154
Microgrid 4
M
Z160
Z132 Z131 Z133
Z157
Voltage Regulator
F-a Feeder Id
Load Zone
Feeder Breaker
Sectionalizing Switch
Tie/Microgrid Switch
M Microgrid
•
Without Microgrid 2,
zone Z73 cannot be
restored!
36
Restoration with/without Microgrids
• Microgrid Enhance Restoration Capability
– Using the capability of microgrids to pick up more interrupted
load (Scenario 1 & 2)
– Microgrids reduce the number of switching operations during
restoration (Scenario 3)
Scenario #
Fault Location
Switching Operations without Microgrids
Switching Operations with Microgrids
1
Zone Z43
‐‐‐
Close: 73‐Microgrid2
2
Zone Z139
Open: 46‐47, 96‐89
Close: 136‐120, 53‐96, 45‐90
Partial Restoration, 315.04 kVA load
should be shed at F‐b
Open:50‐43, 90‐92
Close: 45‐90, 73‐Microgrid2,
136‐120
3
Zone Z23
Open: 49‐50, 90‐92
Close: 78‐9, 53‐96, 136‐120
Close: 39‐Microgrid1
37
Improvement in Reliability
• SAIDI,
SAIDI SAIFI and Outage Cost are calculated.
calculated *
Index
Without Microgrids
With Microgrids
Improvement
SAIDI
(minute/year)
196.54
182.64
7.07%
SAIFI (/year)
0.7800
0.7800
0 % **
Outage Cost
(k$/year)
3729.8
3426.5
8.13%
* Assume that the permanent failure rate for each zone is 0
0.02,
02 the mean
time to operate a (manual) switch is 90 minutes, and the cost for outage
load is $1 per kW per minute, respectively.
** In order to improve SAIFI, remote-controlled ability should be added.
38
Enhance Restoration Capability by Adding
Remote Control Functions
• A remote‐controlled switch (RCS) can be operated by
a distribution system operator. A manual switch is
operated by the field crew
crew.
• Installing RCSs enhances
restoration capability of
a distribution system.
39
Restoration Scheme Without RCSs
• A fault occurs at zone Z99
• Mean time to operate a manual switch is assumed to be 60 minutes
Z15
Z28
Z25
Z29
Z31
F-a
Z1
Z24
Z22
Z4
Z17
Z35
Z30
Z8
Z18
Z5
Z23
Z20
Z39
Z6
Z7
Z38
Z19
Z2
Z14
Z16
Z9
Z40
Z33
Z12
Z3
Z10
Z13
Z26
Z27
Z66
Z67
FB-a
Z34
Z21
Z32
Z36
Z11
T1
Z41
Z64
Z62
Z44
Z70
Z65
Z69
Z57
Z75
Z71
F-b
Z55
Z68
Z37
Z48
Z58
T2
Z45
Z63
Z60
Z79
Z46
Z47
Z78
Z59
Z42
Z54
Z49
Z56
Z80
Z73
Z52
Z43
Z50
FB-b
Z74
Z61
T3
Z72
Z76
Z51
Z53
T7
Z77
S
SubTransmission
Node
Z111
F-c
Z81
Z104
Z102
Z84
Z95
Z108
Z116
Z115
Z110
Z88
Z98
Z109
Z105
Z97
Z100
Z85
Z103
Z86
T6
Z113
Z119
Z87
Z83 Z93
Z118
Z99
Z82
Z94
Z96
FB-c
Z114
CL1
F-d
Z121
Z144
Z112
Z101
Z142
Z117
Z135
Z148
T4
Z149
Z145
Z89
Z92
CL3
Z156
Z137
Z140
Z159
Z124 Z150
Z128 Z138
Z125 Z143
Z126
Z127 Z139
Z141
Z155
Z152
Z106 Z107
Z91
Z134
CL2
Z123
Z136 Z129
Z130
Z146 Z147
FB-d
Z154
Z160
Z157
Voltage Regulator
F-a Feeder Id
Load Zone
Feeder Breaker
Sectionalizing Switch
Critical
Load
Outage Time
(min)
CL1
180
CL2
300
CL3
360
Z153
Z158
Z122
Z90
Z120
T5
Z151
Recovery Process
• Open “87-99” and “99-82”
to isolate Z99;
• Reclose
Re l e “FB-c”
“FB ” to
t restore
et e
loads upstream Z99;
• Open “90-92” and close
“T3” and “T5” to restore
loads downstream Z99 in
two groups.
Tie Switch
Z132 Z131 Z133
40
Restoration Scheme With RCSs
• A fault occurs at zone Z99
• Mean time to operate a manual switch is assumed to be 60 minutes
• Mean time to operate a RCS is assumed to be 1 minute
Z31
Z25
F-a
Z1
Z24
Z22
Z4
Z17
Z35
Z30
Z18
Z8
Z5
Z23
Recovery Process
Z15
Z28
Z29
Z20
Z39
Z6
Z7
Z38
Z19
Z2
Z14
Z16
Z9
Z40
Z33
Z12
Z3
Z10
Z13
Z26
Z27
Z66
Z67
FB-a
Z34
Z21
Z32
Z36
Z11
T1
Z71
F-b
Z41
Z64
Z62
Z44
Z55
Z68
Z37
Z75
Z70
Z48
Z58
Z69
Z65
Z57
Z60
Z45
Z63
T2
Z46
Z79
Z47
Z78
Z59
Z42
Z54
Z49
Z56
Z80
Z73
Z52
Z43
Z50
FB-b
Z74
Z61
T3
Z72
Z76
Z51
Z53
T7
Z77
S
SubTransmission
Node
F-c
Z81
Z104
Z102
Z84
Z116
Z115
Z110
Z88
Z98
Z97
Z85
T6
Z113
Z105
Z109
Z111
Z95
Z108
Z103
Z100
Z119
Z86
Z87
Z83 Z93
Z118
Z99
Z82
Z94
Z96
FB-c
Z114
CL1
Z117
Z151
F-d
Z121
Z144
Z112
Z101
Z142
Z156
Z135
Z148
T4
Z149
Z145
Z137
Z140
Z124 Z150
Z128 Z138
Z125 Z143
Z141
Z155
Z152
Z126
Z89
Z92
CL3
Z127 Z139
Z91
Z134
CL2
Z153
Z123
Z158
Z122
Z106 Z107
Z120
T5
Z159
Z90
Z136 Z129
Z130
Z160
Z157
Voltage Regulator
F-a Feeder Id
Load Zone
Feeder Breaker
Sectionalizing Switch
Tie Switch
Critical
Load
Outage Time
(min)
CL1
3
CL2
5
CL3
6
Z146 Z147
FB-d
Z154
• Open “110-88” and “89-90” to
separate critical loads from
faulted zone;
• Reclose “FB-c” to restore CL1;
• Open “90-92” and close “T3”
and “T5” to restore CL2 and
CL3;
• Open “87-99” and “99-82” and
close “110-88” and “89-90” to
restore other loads.
Z132 Z131 Z133
41
DA: Adding Remote
Remote‐Controlled
Controlled Ability
Z15
Z28
Z29
Z31
F-a
Z1
Z24
Z22
Z4
Z30
Z8
Z18
Z40
Z33
Z12
Z3
M
Z17
Z35
Microgrid 1
Z25
Z20
Z5
Z23
Z6
Z39
Z7
Z38
Z19
Z2
Z14
Z16
Z9
Z13
Z10
Z26
Z27
FB-a
Z34
Z21
Z32
Z36
Z11
T1
Z71
Fb
F-b
Z41
41
Z64
64
Z62
62
Z55
Z68
Z37
Z75
Z44
Z70
Z48
Z58
Z69
Z65
Z57
Z60
Z45
Z63
Z46
M
Z79
Z47
4
Microgrid 2
T2
Z78
Z59
Z42
Z54
Z49
Z56
Z80
Z73
Z52
Z43
Z50
Z66
Z67
FB-b
Z74
Z61
T3
Z72
Z76
Z51
Z53
T7
Z77
S
SubT
Transmission
i i
Node
Z111
F-c
Z81
Z104
Z102
Z95
Z108
Z116
Z115
Z110
Z84
Z88
Z98
Z105
Z97
Z100
Z119
Z86
Z87
Z85
T6
M
Z103
Z83 Z93
Z118
Z99
Z82
Z94
Z96
FB-c
Z114
Z89
Z92
Z112
Z101
Microgrid 3
Z113
Z109
Z90
Z106 Z107
Z91
Z120
Z117
F-d
Z121
Z144
Z142
Z135
Z148
T4
Z149
Z145
T5
Z151
Z156
Z137
Z140
Z159
Z124 Z150
Z128 Z138
Z125 Z143
Z126
Z127 Z139
Z141
Z155
Z152
Z153
Z123
Z158
Z122
Z134
Z136 Z129
Z130
Z146 Z147
FB-d
Z154
Microgrid 4
M
Z160
Z132 Z131 Z133
Z157
Voltage Regulator
F-a Feeder Id
Load Zone
Feeder Breaker
Sectionalizing Switch
Tie/Microgrid Switch
M Microgrid
Remote-Controlled
Switches (RCSs)
•44 ffeeder
d bbreakers
k
•5 normally closed
sectionalizing switches
•3 normally closed tie
switches
it h
•3 microgrid switches
•Marked in red color.
42
Example – PNNL Test System with RCSs
Z15
Z28
Z25
Z29
Z31
F-a
Z1
Z24
Z22
Z4
Z17
Z35
Z30
Z8
Z18
Z20
Z5
Z23
Z6
Z39
Z7
Z38
Z19
Z2
Z14
Z16
Z9
Z40
Z33
Z12
Z3
Z10
•
Z13
Z26
Z27
FB-a
Z34
Z21
Z32
Z36
Z71
F-b
Z41
Z64
Z62
Z44
Z55
Z68
Z37
T1
Z75
Z70
Z48
Z58
•
Z11
Z69
Z65
Z57
Z60
Z45
Z63
T2
Z46
Z79
Z47
Z78
Z59
Z42
Z54
Z49
Z56
Z80
Z73
Z52
Z43
Z50
Z66
Z67
•
FB-b
Z74
Z61
T3
Z72
Z76
Z51
Z53
T7
S
S b
SubTransmission
Node
Z111
Z81
Z104
Z102
Z84
Z116
Z115
Z110
Z88
Z98
Z97
Z85
T6
Z113
Z105
Z109
F-c
Z95
Z108
Z77
Z103
Z100
Z119
Z86
Z87
Z82
Z94
Z96
FB-c
Z114
CL1
F-d
Z121
Z144
Z112
Z101
Z142
Z117
Z135
Z148
T4
Z149
Z145
Z89
Z92
CL3
Z156
Z137
Z140
Z159
Z124 Z150
Z128 Z138
Z125 Z143
Z126
Z127 Z139
Z141
Z155
Z152
Z106 Z107
Z91
Z134
CL2
•
Z153
Z123
Z158
Z122
Z90
Z120
T5
Z151
•
Z83 Z93
Z118
Z99
Z136 Z129
Z130
Z146 Z147
FB-d
Z154
Z160
Z132 Z131 Z133
Z157
Voltage Regulator
F-a Feeder Id
Load Zone
Feeder Breaker
Sectionalizing Switch
Tie/Microgrid Switch
4 out of 4 feeder
b k are RCS
breakers
RCSs
12 out of 156
normally closed
sectionalizing
switches
i h are RCSs
RCS
7 out of 7 normally
closed tie switches
are RCSs.
RCS are marked
RCSs
k d in
i
red color.
•
3 critical loads ((CLs))
in Feeder F-c.
CLs are marked in
green color.
43
Improvement in Reliability by DA
• SAIDI,
SAIDI SAIFI and Outage Cost are calculated.
calculated *
Index
Without RCSs
With RCSs
Improvement
SAIDI
(minute/year)
182.64
73.74
59.63%
SAIFI (/year)
0.7800
0.7081
9.22%
Outage Cost
(k$/year)
3426.5
1230.6
64.09%
* Assume that the permanent failure rate for each zone is 0
0.02,
02 the mean
time to operate a manual/remote-controlled switch is 90/1 minutes, and
the cost for outage load is $1 per kW per minute, respectively.
44
R&D Need: Microgrids Increase Resilience
• Smart grid applications enhance resilience of distribution systems
– DG/DER
DG/DER, Microgrid resources survivability must be high
– Access through DERs to critical
loads must be maintained
Mi
Microgrid
id
Source: Jesse Jenkins, “The Smart Grid and Natural Disasters”,
http://theenergycollective.com/dickdeblasio/155946/smart-grid-andnatural-disasters
Restoration schemes considering
DERs and Microgrids
45
Future Needs
• Simulation tools: Simulate response of distribution
systems during extreme events
• Restoration strategy
gy in extreme events
– Multiple faults, large amount of outage load, lack of power
sources, T&D network damaged
• DA: Optimal placement of AMIs and RCSs
– Consider both functional requirements and cost‐benefits.
• DERs/Microgrids supporting distribution Restoration
during extreme events.