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;