Self Healing Networks
Sivakumaran GovindarajanYves ChollotAnil Kadam
Feb 22nd, 2012
2
What is a self healing network ?
3
A self-healing grid is one capable of automatically sensing, isolating and instantaneously responding to power system disturbances, while
continually optimizing its own economic as well as operational performance.
Self healing grid - Definition
Self healing is in essence, the smart grid’s immune system.A strong immune system enables the grid to perform continuous, online self
assessment to detect existing or emerging problems, predict future potential problems, and initiate immediate corrective responses.
4Source: KEMA
Dutch outages
Why self-healing networks ?
5
●Financial consequences of defective power supply● For end users
●Loss of revenues (non productive time)●Deterioration of production or even process itself
● For electricity suppliers●Loss of revenues●Maintenance costs●Damage to distribution hardware●Customer satisfaction●Regulator penalties
Source:David ChapmanCopper DevelopmentAssociation
Typical financial loss per outage
Semi-conductors production 3,800,000 €Financial firm 6,000,000 € per hourInformatics Centre 750,000 €Telecommunications 30,000 € per minuteSteel works 350,000 €Glass industry 250 000 €
Electricity outages: an economic stake
6
●Measured broadly by indices like SAIDI, SAIFI, CAID I, MAIFI●SAIDI (System Average Interruption Duration Index) can vary from a few
minutes to several hours
●SAIFI (System Average Interruption Frequency Index) can vary from 0,1 to 10 and more
●Generally no data is available if interruption is p lanned or unplanned●Unplanned interruptions need attention
●An example from SP AusNet:
SP Ausnet – 2006-10 Asset mgmt plan
Indicators of dependability
7
4.233.0210:483.073,54,884Thiruvanantha-puram
3.412.000:471.789,43,099Mumbai (BEST)2007-08
1,17,912
14,32,363
11,10,013
5,38,417
No of consumers
255.0073.003:560.03Patiala
05.533.790.5313.00Ahmedabad
57.3313.244:210.01TPDDL (NDPL)
179.2750.731:08286.9Vishakhapatnam
Ave duration of outage per feeder
No of outages per feeder
Ave duration of outage per consumer
No of outages per consumer
Name of town
Hh:mm Hh:mm
Extracts from CEA report
Interruption data for some towns (2009-10)
8
Reliability indices in Europe
9
Ali Ipakchi, Kema Inc
Compare this with other regions
10
• Slow evolution of distribution network, • Apparition of digital control systems and advanced DMS • High speed, low cost communication
KWh
KWhHospital
Public DistributionMain Substation
Urban Distribution
KWh
20MVA33/11kV
20MVA33/11kV
630A 630A 630A 630A
200A 200A 200A630A
630A
630A 630A
630A 630A630A
1250A 1250A1250A
Process Industry
630A
200A630A
630A
630A 200A
200A
630A
630AG
KWh200A
200A
200A
G
Leisure Complex
630A
630A
630A
Typical European network style
Indian Distribution N/W has evolved over time
80s
Static and Electromechanical protection relays and systems;
Manned Substations
No FRTUs Radial & Ring type distribution system
No SCADA & DMS Systems
90s
Numericalprotection relays and systems;
Manned Substations
Few FRTUs Radial & Ring type distribution system
With Limited SCADA / DMS Connectivity
Few FPIs
2012
Numericalprotection relays and systems;
Un-Manned Substations
Full FRTUs Radial & Ring type distribution system
With Full SCADA / DMS Connectivity
Full FPIs Automation with Reclosures, Sectionalisers
Future
DER integrationSmart distributed substation
New self-healing system
Full Connectivity
Smart MV/LV
Numericalprotection relays and systems;
Un-Manned Substations
Full FRTUs Radial & Ring type distribution system
With Full SCADA / DMS Connectivity
Full FPIs Automation with Reclosures, Sectionalisers
Individual Consumer Connectivity (AMI)
11
Self healing – Today’s Grid
Today’s Transmission grid are with many self-healin g features:
●Present Mesh network, built-in redundancy & advanced protective system (Single
phase tripping, Auto‐reclosing, Power Swing Protection, auto-sectionalizing etc.,).
●Pilots � on FACTS, DLR, WAMS ongoing
Today’s Distribution grid design is not with many s elf-healing features:
●Most DA and substation automation (SA) systems are applied at a local level, using
local information for decision making.
●Recent deregulation, lack of distributed resources /intelligent networking
capabilities, Desperate applications designed for standalone applications
12
Self healing grid – Examples
Generation Transmission Distribution
Local Object Protection
WAMS – P&C
DLR
�Fault Detection, Isolation and restoration� Voltage and VAR Management� Network Reconfiguration (Load
Balancing / Loss Minimization (Efficiency)�Auto Demand Response to bridge the
� Demand –Supply Gap
13
Centralized
The FRTU react automatically to reconfigure the network and
inform eventually the SCADA
Decentralized
The SCADA manages the decision and send restoration control orders to the FRTU.
The FRTU are passive
>5 min < 500 ms<1 min
Simple to very complex network schemes
Simple network schemesSimple to complex network schemes
Both FRTU and SCADA/DMS are involved
in the decisions.
Semi decentralized
Overload and DG easyto manage from the
DMS data base
Overload management to be shared between DMS
and FRTU
Load management more difficult to manage
Various approaches exist for Distribution Grid Management
14
● Do you see an evolution towards centralized architectures? Decentralized? Hybrid?
● Do you need to improve your response time ? To what extent?
Various approaches exist for Distribution Grid Management
15N.O.point
A B C D E
STEDIN•Open loop with LBS•communication between FRTU (GPRS)•Restoration < 1min
ENEL•Open loop with CB•No communication between FRTU•Restoration < 1min•Multiple trip/close operations•Chronologic selectivity for earth fault
• Close ring with CB• Cable differential protection• No customer interruption
Hong-Kong
• Double network with ATS• LBS
Double Radial
Example of decentralised solutions
16
HV/MV sub
MV/LV sub
HV/MV sub
HV/MV sub
RTU
GPRSIEC 104DNP3IEC 61850
GPRS - Optical
Modbus-DNP3 -IEC 104
61850
FPI
Voltage detection
UPSMotorisationinterface
Load measurement
Historical
Automation61131
DMS
A cost effective Self Healing Grid solution
17
HV/MV sub
MV/LV sub
HV/MV sub
HV/MV sub
FRTU
1 - Fault detectionCB trips
RTU exchange fault detectionRTU exchange load before trip
2 - IsolationRTU decision of isolationLBS openFaulty cable is isolated
3 – Restoration Step 2
Decentralised solution
Semi-decentralised solution
RTU exchange (isol + no volt)
RTU close the LBSPower fully restored
DMS analyse the loadDMS send close orderPower fully restoredDMS
# 0,5s
# 0,2s
# 0,5s
# 1 min
- Only LBS- Peer to peer communication
N.O.
RTU send isolation doneRTU or protection close the CB
3 – Restoration Step 1
Power restored partially
SHG : 1- Ready to add CB for S
AIDI extra improvement ?
2- Ready to add CB to avoid DG deconnection before
restoration ?
3- Are the field operator confident w
ith Self Healing ?
A cost effective Self Healing Grid solution
18
Smart Metering integration
Smart Metering integration
Reduce tech. and non technical losses on LV network
Keep LV network stable with DG proliferation
Ease LV network maintenance & evolution
Reduce outage time on LV network
LV management integration
LV management integration
Monitor LV power supply quality
Reduce losses
Monitor the load & control the peak load
Reduce the transformer fault
MV Feeder Automation MV Feeder Automation
Monitor the MV load and voltage
Reduce operation & maintenance costs
Reduce Outage Time
Applicable in a European-type architecture (AMI via PLC to the substation)
New MV/LV functions to optimize network utilization
Schneider Electric Infrastructure19
ISGF – 22-02-2012
……
End user < 36kVALV network
Feeder automation solution : FPI & RTU
MV/LV substationCOM (WAN)
GSM
GPRS
PSTN
Internet
WiMax
SCADA/DMS
Smart Meters
AMI Solution
AMI Head end PLC on LVCOM (WAN)
GSM
GPRS
PSTN
Internet
WiMax
Concentrator
AMI Integration to DMS – A Step Beyond 1/2
Schneider Electric Infrastructure20
ISGF – 22-02-2012
Monitoring
MV/LV substationCOM (WAN)
GSM
GPRS
RTC
Internet
WiMax
SCADA/DMS
KS FA
Feeder Automation
LV network
PLC on LV
Smart Meters
AMI
Concentrator
+ RTU or FPI
Flexible LV Integration
with MV
AMI Integration to DMS – A Step Beyond 2/2
Schneider Electric Infrastructure21
ISGF – 22-02-2012
Self healing Grid – Benefits
● Improved Reliability: Self healing will produce a substantial improvement in grid
reliability.
● Improved Security: Self healing decreases the threat of a security attack because
energy sources are distributed and self healing technologies can maintain or restore
service during and after attack.
● Safety: Can quickly locate and de‐energize downed wires. Faster restoration will
reduce the impact to “life‐support” systems . Fewer outages mean fewer opportunities
for criminal acts.
●Quality: Could detect and correct power quality issues. Power quality issues represent
large annual cost to society. (estimated to be in the tens of billions of dollars).
● Environmental: self healing grid accommodates multiple green resources. Helps in
reducing environmental impact associated with outages and major equipment failures.
More efficient grid means lower electrical losses (hence lower emissions).
22
2.761.044
5.512.163
15.796.232
65.6931.171
SAIDISAIFIModel
Source: Rienaldo Burian, Cesar Augusto Cactano, Annibel Hetem - Brazil
Model 1 – Fdr CB w/o AR Model 2 – Fdr CB with AR
Model 3 – AR without sectionalers Model 4 – AR with sectionalers
Impact self -healing on KPI ’s(Example of Auto-Reclosing)
23
Annual cost w/o sectionalising
Annual cost with sectionalising
Outage costs comparison
Schneider Electric Infrastructure24
ISGF – 22-02-2012
Self Healing Grid – Barriers 1/2
● Financial Resources: Regulators require extensive proof before authorizing major
investments, concerns about rapidly changing technology is also high
●Government Support: Industry may not have the financial capacity to fund new
technologies.
● Compatible Equipment: Some older equipment must be replaced as it cannot be
retrofitted to be compatible with self‐healing requirements. Early retirement of
equipment before ROI might become an issue.
● Policy and Regulation : New regulatory model should be considered that decouples
delivery company profits from sales volume. Instead, a model that rewards achievement
of the principal characteristics will accelerate smart grid progress, particularly in the area
of self healing.
Schneider Electric Infrastructure25
ISGF – 22-02-2012
Self Healing Grid – Barriers 2/2
● Speed of Technology Development:
� Integrated, Secure, Reliable high‐speed communications platform
� Intelligent electronic devices
�Distribution automation schemes with distribution‐level self‐healing capabilities to
accommodate all DER
�Cost‐effective, environmentally‐acceptable DER, including micro grids and energy storage
�DR systems using real‐time pricing
�Advanced transmission protection schemes that provide rapid area‐wide response to
system threats;
�Advanced analytical tools.
�Tools to accommodate two‐way flow on existing distribution circuits;