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SCADA / DMS
DISCOM’S SUB STATIONS & DISTRIBUTION NETWORK
MASTER CONTROL CENTRE DISASTER CENTRE
Load Shed Application (LSA)
Fault Management and System Restoration (FMSR)
Loss Minim.via feeder reconfiguration (LMFR)
Load Balancing via feeder reconfiguration (LBFR)
Network Connectivity Analysis (NSA)
Load Flow Applications (LFA)
State Estimation (SE)
Voltage VAR Control (VVA)
Operation Monitor (OM) Distribution Load Forecasting (DLF) Dispatcher Training Simulator(DTS)
Contents
Introduction
Historical Developments
Over view of Power Networks
Protection Systems
SCADA Systems - RTU
Communication Systems & Security issues
Contents (Contd.)
Distribution Automation
Quality Assurance
Utility IT Requirements
Case Study
Q & A – Discussions
Introduction
Stages involved in Power Distribution
AU
TOM
ATION
Sub Transmission System
132-66kV
66-33 kV 11kV 11kV
440-220 V 11kV-440 V
Distribution Operations
Monitoring the power system
Making adjustments and maintaining the system so that it can be used reliably, efficiently, and safely
Repairing the system as quickly as possible in response to incidents such as equipment faults
Tracking and maintaining system reliability data
System planning and expansion to serve new customers
So, within this context, objectives may be summarized as follows.....
Objectives
Consistent with National Electricity Policy, to improve reliability and quality of service of distribution system by
Reducing frequency and duration of power interruptions to targets consistent with best international practice
Maintaining power quality with respect to voltage and frequency excursions
To operate efficiently and safely by
Minimizing power losses
Applying manpower resources effectively
RTU
COMMUNI-
CATIONS
SCADA
DMS
User
Interface
Data
Acquisition
DMS Applications
SCADA
Functions
SCADA Platform Environment
Maintenance Management
Decision Support Systems
OMS Crew Management
GIS
Other Applications
SCADA/DMS Functional/Architectural Overview
Corporate Data Accessibility and
Availability
CPRI-UARC
R
T
U
R
T
U
Primary Plant
Interface
KEY ELEMENTS of DMS
Data & Control
Pathway
Communications
Town Master Station
Substation
1 2
3
4 MPLS/MLLN
GPRS/
CDMA
MPLS
F
R
T
U
1
2 RTU
3
4
Communications
Master Station
Line
5
5 Control Room,
Corporate Usage,Backup, LD
Control Room
Operators
Outage Analysis
Operational analysis,
decisions, issue controls
5
MPLS / MLLN
DR Centre SLDC
Reporting
Analysis
Historical Developments
Historical Developments
• SCADA system is in use since a long time (with conventional telephone technology)
• Deployment of SCADA system accelerated with the development of microprocessors
• Present day SCADA system are based on compact RTUs and latest communication technology including mobile communication system.
Historical Developments (contd.)
• SCADA Communication protocol development started with proprietary from industries and users.
• To make interoperable, DNP protocol emerged as open protocol standard during early 1993 in USA and Canada
• During same period, IEC 60870 -5 has also emerged as international standard for SCADA applications
• IEC 61850 series of standard is now available for IEDs.
PROTECTION OF POWER SYSTEM
The basic function of a relay or protection
equipment is to detect and isolate the fault section at
the earliest so that continuity of supply is restored in
the rest of the system.
Faults in Power System
Faults can be either symmetrical or asymmetrical or
unbalanced.
• Symmetrical faults involve all three phases
• Asymmetrical faults include phase to phase, phase to
phase to ground or single line to ground.
Protective Relays
that protect power systems from
faults:
Short circuits
other abnormal conditions
underfrequency, overvoltage, etc.
To sense the abnormal conditions
Initiate the isolation of faulty section
PROTECTION REQUIREMENTS:
Protective relays should be :
• RELIABILITY
DEPENDABILITY
SECURITY
• SELECTIVITY
• SENSITIVITY
• STABILITY
• SPEED
• COST
• Design should achieve balance
Over Current Protection
There are two types of over current relays
• Instantaneous (50)
• Time over current
Protection of Radial system by Over current relay
51 51 51
Fault
B1 B2 B3
Differential Protection • Differential protection is a unit type of protection.
• It is a very reliable type of protection used for protection of Transformers,
Bus bar and Transmission lines.
Protected
Equipment
Relay
Distance Protection
• A distance relay operates based on the measurement of the impedance.
Impedance measuring relays are used when over current relays do not
provide adequate protection or short circuit current is low, the operating time
is independent of the current magnitude.
R
X
Plain impedance characteristic
Modified characteristics are given in Figure
Quadrilateral characteristic
Zones of Distance protection
Zone1
Zone 2
Zone3
t2 t3
Zones of Distance protection
• Zone1 – Upto 80 to 90% of protected line with no intentional time delay
• Zone 2 – Up to 50 % of the adjacent line from remote end delay 0.3 sec to
0.5 sec
• Zon3 – up to 100 % of the adjacent line + 25 % of second line delay 0.6
sec to 1 sec
PROTECTIVE RELAY
TECHNOLOGY
ELECTRO
MECHANICAL
STATIC DIGITAL
NUMERICAL
Self-supervision
Setting groups
Programmable logic
Adaptive schemes
Multiple protection characteristics
Communication capability
Instrumentation features
FEATURES OF NUMERICAL RELAYS
Classification of relays by construction type
Based on type of construction relays can be classified into
• Electro magnetic
• Solid state
• Microprocessor
• Numerical
Modern Numerical relays are built with integrated functions. Advantages of
Numerical relays are: • Reliability
• Multi-functionality
• Self diagnosis
• Events and disturbance recording facility
• Communication capabilities
• Adaptive protection
Electromechanical / static versus Numerical Relays
Electromechanical & Static Relays
Numerical Relays
Single Function – Single Characteristic
Multiple Functions – Multiple Characteristics
Dynamic change of protection characteristics not possible
Dynamic change of protection characteristics - programmable
Only fault detection, isolation & location
Additional features of Control, Metering, Monitoring and communication
Numerical relays in Substation automation environment
• In an substation automation environment, Numerical relays help in
visualizing and understanding the fault and operation. Logics can be
configured in the relay for having effective control and protection of the
system with out hard wiring. Multiple relay settings groups in Numerical
relay can be utilized for faster power restoration in emergencies.
• Adopted relay settings for standard power flow will not be suitable for
emergency load management. During such situations second relay
setting group with suitable relay setting can be adopted. Through
station automation group changing can be done from remote HMI and
power restoration through different network is faster with suitable relay
settings.
• On-line relay settings and fault data record down loading is possible.
Faster tripping diagnosis makes faster restoration of system and
immediate corrective actions possible.
Supervisory Control and Data Acquisition
(SCADA)
SCADA Functions:
• Time synchronization of RTUs,, FRTUs & FPIs(if time synch is
supported in FPI)
• Data Exchange among the various SCADA/DMS sub-
system(legacy), IT systems, State load dispatch centres.
• Data Processing
• Continuous real-time data storage and playback
• Sequence of event processing
• Supervisory Control
• Fail-soft capability
• Remote database downloading ,diagnostics & configuration
• GIS adaptor
• Information Storage & Retrieval (ISR)
• Historical Data information & Retrieval and
• Data recovery (DR)
REMOTE TERMINAL UNIT(RTU)
• Microprocessor based equipment or intelligent device
• Acquiring field data & monitoring
• Transmitting telemetry data to the Control Centre
and/or altering the state of connected objects based on
control messages received from the Control Centre.
The functions of RTU’s integrated into the design include:
• Circuit Breaker Control
• Feeder monitoring
• Feeder protection sequences
The salient features include
• Programmability
• Sequence of Events (SOE) Recording
• Programmable Logic Functions
Data Acquisition
RemoteTerminal Unit
HARDWARE CONNECTIVITY DIAGRAM FOR SCADA
AT SUBSTATION RTU
MAIN CPU
BOARD PSU
COMMN BOARD
A N A L O G I / P
D I G T A L I / P
C O N T R O L O/P
TERMINAL BLOCK
TERMINAL BLOCK
TERMINAL BLOCK
REMOTE TERMINAL UNIT
TRANSDUCER O/P TERMINAL
MVAR VOLT MW
TRANSDUCER I/P TERMINAL P T SEC
110VAC
CT SEC 1 AMPS
F R O M
S W I T C H Y A R D - F I E L D
EVENT LOGGER PANEL
D R I V E R
R E L A Y
TRANSDUCER PANEL
COM PORT
R
T
U
Pictorial view
SCADA Human–Machine Interface
(HMI)
• A HMI is the apparatus (Monitor / Display system)
which presents process data to a human operator,
and through which the operator controls
• Usually HMI will be situated in the Master Control
Centre or it can be even at substations where the
system can be monitored & controlled.
Communication Systems
• Communication system is vital for any SCADA / DMS
system
• Communication between Master Controller Centre
and RTUs (substations) and FRTUs (at feeder –
RMU/Sectionlizer/Autoreclosure locations)
• Control signal flow, status (digital) and analogue
signals (measurends like bus voltage, feeder current,
power, reactive power, energy consumption etc.)
Communication Systems
• Data Acquisition - RTU/FRTU/RMU/FPI’s
• Time Synchronization – RTU/FRTU/FPIs
• Data Exchange – IT System under RAPDRP
• Continous real time storage & playback
• SOE
• Supervisory Control
• Remote database downloading, diag.& config
• CIM Compliance IEC 61968
• GIS Adaptor – to support native adaptors, CIM/XML using Model & Data Exchange over IEC 61968
Enterprise SOA based bus
• ISR
• LDC & DR
• DAS
• LAN
SYSTEMS REQUIRING COMMUNICATIONS
SYSTEMS REQUIRING COMMUNICATIONS
COMMUNICATIONS OPTIONS
SCADA FUNCTIONAL REQUIREMENTS
COMMUNICATIONS OPTIONS
ENVIRONMENTAL REQUIREMENTS
COMMUNICATION REQUIREMENT ELEMENTS
COMMUNICATIONS OPTIONS
COMMUNICATIONS OPTIONS
SCADA TOPOLOGY
COMMUNICATIONS OPTIONS
REQUIREMENT OF STANDARDS
COMMUNICATIONS OPTIONS
UCA AND IEC 61850 PROTOCOLS
COMMUNICATIONS OPTIONS
DESIGN FACTORS FOR COMMUNICATIONS
COMMUNICATIONS OPTIONS
TRANSMISSION MEDIA CLASSIFICATIONS
COMMUNICATIONS OPTIONS
Electromagnetic Spectrum for Wireless Transmission
COMMUNICATIONS OPTIONS
Electromagnetic Spectrum for Wireless Transmission
COMMUNICATIONS OPTIONS
Conducted or Guided Media Transmission
Communication Technologies
Public communications
• Dedicated Leased Telephone Line from service providers like BSNL.
• GSM/EDGE/GPRS / CDMA / 3G communication from Service
Provider like BSNL, Airtel etc.
Utility owned communications
• Distribution Line carrier Communications (DLC).
• Dedicated Utility Multiple Address Radio Communications (MARS).
• Optical fiber cable (OFC) communication run on overhead lines /
underground power lines
• Satellite Communications ( VSAT)
Public Telephone Communications:
• Two way communication system with data rate of 64
kbps to 8 Mbps with leased lines
• Good reliability in urban areas.
• Suitable for substation SCADA.
GSM/ GPRS/ CDMA
• Availability of Multiple mobile telephone operators in
urban locations
• Best suited communication for widely scattered devices in
distribution network like DTR’s, FRTUs,Switches etc.
• Low capital cost and only (low) recurring charges based
on usage.
Optical Fiber cable • Arial self supporting outdoor Optical Fiber cable are freely
suspended on utility 33 kV poles connecting substations and
control centre in in ring / mesh topology
• Protective outer jacket with one messenger and one fiber cable
which contains 4 /6/8 strands of multimode fibers.
• Ease of installation and reduces time and cost.
• Gigabits of band width and highly reliable and secured
communication medium with free from all interference
• High capital costs
RTU to Central Monitoring Station
IBM Compatible
Modem
Modem
COMMUNICATION LINK
SCADA Schematic Diagram with fiber links
FO Substation to Control Centre
FO
wit
hin
S
ubst
atio
n
Multi Access Radio Systems (MARS):
• MARS is usually owned by the utility,
• Require license from the authority of (in India Wireless Planning & Coordination)
• Consist of a master radio which communicates with several remote radios.
• Master is located at central place on mast of adequate height such that line of sight is
available for a radius of about 30 km all around.
• Master will be able to poll about 1000 remotes in the area and perform SCADA
function.
• It is a two way communication system
• It is primarily intended for data communication.
• Voice communication with master is provided by means of hand sets that can be
plugged into remote unit.
• During the period of voice communication, the polling will be interrupted. Therefore
voice usage is restricted to system emergencies only.
• Each system uses a pair of frequencies, one for master to remote communications
and the other for remote to master, so that one outbound and one inbound
transmission can occur concurrently.
• Frequency bands of 400 MHz, 900 MHz, 2.4 GHz and 5 GHz
Satellite Communication (VSAT)
• A satellite communication system using Very Small Aperture Terminal (VSAT)
• VSAT is a point to multipoint star network like TDMA.
• Consists of one single Hub and number of remote Personal Earth Stations
(PES).
• Communication system between Hub and remote PES is through two
separate radio links.
• The link from remote PES to Hub is called as ‘in bound’ and from Hub to the
remote PES is called as ‘out bound’.
• The in route bandwidth is 64-128 KBPS and out route band width is 128 – 512
KBPS, which is shared by a number of PES using TDM.
• Data from central Hub is broadcast to all remote PES, which are in listen
mode. Each remote VSAT listening to the Master will decode only the data
addressed to one of its ports.
• Satellite transponder acts like a repeater between hub and remote
• No end user transmission either originates or terminates at the satellite.
• In India extended ‘C’ band with up link in the 6.315/6.815 GHz and down link
in the 4.09 / 4.59 GHz range is used.
• The Multi Frequency Time Division Multiple Access (MFTDMA) is the latest
technology which uses optimum bandwidth for communication.
The structure of SCADA Communication
Protocol
• ISO/IEC 7498 - 1994 Open Systems Interconnection(OSI) basic reference
model for communicational
• seven layers
7- Application Layer : SCADA application, DMS
6- Presentation Layer: Common data representation
5-Session Layer: Connection between end users
4 -Transport Layer: end-to-end reliable delivery
3- Network Layer: routing & relaying data
2- Data Link Layer: error free transmission
1- Physical Layer: physical data path
Standard Protocols
• IEC 60870-5 -101 (Serial Communication)
• IEC 60870 – 5-104 (Ethernet compatible Network communication)
• IEC 61850 Network compatible communication for IEDs
• DNP 3
SCADA Security issues
• Vulnerable due to
• Adoption of open standards for protocols & open
solutions and moving out from the proprietary
technologies
• Increased number of connections between SCADA
systems and office IT networks
• Web interface to SCADA Systems
• the lack of concern about security and authentication
in the design, deployment and operation of some
existing SCADA networks
• Myths
• SCADA systems have the benefit of security through
obscurity through the use of specialized protocols and
proprietary interfaces
• SCADA networks are secure because they are physically
secured
• SCADA networks are secure because they are
disconnected from the Internet.
Security concerns in SCADA systems
• SCADA security policies
• Firewall architecture, DMZ, and rule based
• Secure remote access to a control center
• SCADA protocol security issues
• Securing field communications
• User authentication technologies and integration with SCADA applications
• Access control principles and implementation
• Active Directory integration with SCADA applications
• Detecting cyber attacks on SCADA systems
• Vulnerability scanning
• Security patch management
• Anti-virus protection and management
• Exceptions – what to do when you can’t implement best practice
• SCADA security standards
21 Steps to Improve Cyber Security of SCADA
Networks 1. Identify all connections to SCADA networks.
2. Disconnect unnecessary connections to the SCADA network.
3. Evaluate and strengthen the security of any remaining connections to the SCADA
network .
4. Harden SCADA networks by removing or disabling unnecessary services.
5. Do not rely on proprietary protocols to protect your system.
6. Implement the security features provided by device and system vendors .
7. Establish strong controls over any medium that is used as a backdoor into the
SCADA network .
8. Implement internal and external intrusion detection systems and establish 24-hour-a-
day incident monitoring .
9. Perform technical audits of SCADA devices and networks, and any other connected
networks, to identify security concerns .
10. Conduct physical security surveys and assess all remote sites connected to the
SCADA network to evaluate their security.
11. Establish SCADA “Red Teams” to identify and evaluate possible attack scenarios .
Contd….
12. Clearly define cyber security roles, responsibilities, and authorities for
managers, system administrators, and users.
13. Document network architecture and identify systems that serve critical
functions or contain sensitive information that require additional levels of
protection.
14. Establish a rigorous, ongoing risk management process.
15. Establish a network protection strategy based on the principle of
defense-in-depth.
16. Clearly identify cyber security requirements.
17. Establish effective configuration management processes.
18. Conduct routine self-assessments.
19. Establish system backups and disaster recovery plans.
20. Senior organizational leadership should establish expectations for cyber
security performance and hold individuals accountable for their
performance.
21. Establish policies and conduct training to minimize the likelihood that
organizational personnel will inadvertently disclose sensitive information
regarding SCADA system design, operations, or security controls.
Interrelationship of IEC 62351 Security
Standards and the TC57 Protocols
Distribution Operations
– Monitoring the power system
– Making adjustments and maintaining the system so that it can be used reliably, efficiently, and safely
– Repairing the system as quickly as possible in response to incidents such as equipment faults
– Tracking and maintaining system reliability data
– System planning and expansion to serve new customers
Objectives
• Consistent with India’s National Electricity Policy, to improve reliability and quality of service of distribution system by – Reducing frequency and duration of power
interruptions to targets consistent with best international practice
– Maintaining power quality with respect to voltage and frequency excursions
• To operate efficiently and safely by – Minimizing power losses
– Applying manpower resources effectively
Reliability Factors
• Reliability depends on many factors which include
– What causes faults such as • Equipment malfunction, animals and vegetation overgrowth
causing short-circuits, human error (e.g., cable strikes, cars
hitting poles), storms/earthquakes, etc.
– Distribution system characteristics such as • Underground and/or overhead feeders, open-loop structure,
availability of alternative sources of power, equipment
ratings, component failure rates, number of cable joints,
effects of ageing, etc.
Outage Time Around the World (minute/year)
462
90 7758
11
0
50
100
150
200
250
300
350
400
450
500
Example (without
DAS)
USA UK FRANCE JAPAN
Average Outage Time per consumer per annum
Example Causes of Failure (From a US Electric Utility)
Equipment Failures
(Resulting In Sustained Outages)Average (1996-2001)
0
20
40
60
80
100
120
140
160
Equ
ipm
ent F
ailu
re
Unk
nown
Act
ivity
/Fore
ign
Obj
ect
Veg
etat
ion
Wea
ther
Dis
trib
utio
n Supp
ly F
ailu
re
Ele
ctrica
l Ove
rloa
d
Oper
atin
g Error
Oth
er C
ircu
it
Impr
oper
Cons
truct
ion
Nu
mb
er
of
Su
sta
ine
d O
uta
ge
s
6 Year Average
Example Failure Rates (From a US Electric Utility)
Overhead Failure Rates
Voltage Circuit
km
Failures
Over
5 Years
Failures
Per km
Per Year
12kV
Main 309 190 0.123
Lateral 217 201 0.185
4kV
Main 241 111 0.092
Lateral 161 70 0.087
Underground Failure Rates
Voltage Circuit
km
Failures
Over
5 Years
Failures
Per km
Per Year
12kV
XLPE 360 33 0.018
EPR 116 9 0.016
PILC 231 64 0.055
PE 242 13 0.011
4kV
XLPE 28 1 0.007
EPR 12 2 0.033
PILC 160 30 0.038
PE 10 0 0.000
Example Failure Rates (The Netherlands Year 2007)
MV Failure Rates in 2007 – The Netherlands
Cable Type Circuit km No. of Failures Failures Per km
Per Year
XLPE 18,316 127 0.0069
PILC 105,970 1,125 0.0106
Reliability Factors (Cont.) – Repair response times such as
• Time to detect fault and notify field crew
• Time for crew to travel, then find and isolate fault
• Time for crew to restore service to some and finally all
customers affected by the fault
– Reliability strategies such as those based on • Use of circuit breakers, automatic reclosers, fuses,
sectionalizing switches, fault indicators, animal guards, etc.
• Maintenance programs, e.g., inspections, tree trimming, real-
time condition monitoring
• Trouble call, outage management, automation systems
Basic Scenario
• Consider the following scenario where distribution operations as at rely on manual operations – Fault indication and/or trouble call received
– Crew dispatched by radio and/or telephone to • Locate fault by inspection and/or other check-out procedures
• Repair damage and return system to pre-fault state
– Crew may also close upstream and downstream switches to restore power to as many customers as possible prior to repairing damage
Reliability Strategies
• Given the basic scenario just discussed, strategies for improving reliability fall into two basic categories
– Reducing frequency of fault occurrence • Use properly selected and maintained distribution equipment
• Reconfigure, replace, or upgrade equipment as necessary
• Use appropriate devices to prevent faults from occurring or at least reduce the number of customers affected
– Minimizing fault repair times • Call centers to allow customers to report outages
• Computer-based Outage Management Systems
• Computer-based Feeder Automation Systems
Outage Management System
• Automatically infers fault location based on customer trouble calls or other indications
• Shows fault location on geographical display of power system so crews can be dispatched immediately to this location
• Displays can be used to show crew positions and reflect repair status as switches are opened and closed
• Tracks number of interrupted customers and corresponding outage durations
Present Operations ( Average time to restore Power Supply 40 Minutes )
Circuit Breaker
R/S feeder R/S feeder
Normally open point
RMU / DT
R/S feeder
Circuit Breaker
R/S feeder
Normally open point
Supply restored manually for part
network typical time 15 – 20 mins
Circuit Breaker
R/S feeder R/S feeder
Normally open point
RMU / DT
CB Trips on fault
Circuit Breaker
R/S feeder R/S feeder
Normally open point now closed manually
Additional network restored
manually, total time 40 mins
Faulty Section
Automation Philosophy
Circuit Breaker
R/S feeder R/S feeder
Remote operation to close switch
Additional network restored, total time
11-18 mins
Circuit Breaker
R/S feeder R/S feeder
Normally open point
Automated RMU / DT with FPI
Circuit Breaker
R/S feeder R/S feeder
Normally open point
FPI indicates passage of fault
current
CB Trips
Circuit Breaker
R/S feeder R/S feeder
Normally open point
Remote Operation of RMU Switch & Partial Restoration of supply – typically 1-2 mins
After Automation ( Average time to restore Power Supply to healthy section 1-2 Minutes)
OMS Concept – Scenario #1
Sub A
Feeder B010
from Sub BFeeder A007
from Sub A
Open
Tie-Switch
Closed
Switches
Distribution
Transformers
Inferred Fault
Location
Customer
trouble calls
Sub A
Feeder B010
from Sub BFeeder A007
from Sub A
Open
Tie-Switch
Closed
Switches
Distribution
Transformers
OMS Concept – Scenario #2
Inferred Fault
Location
Customer
trouble calls
Customer
trouble calls
11 kV Overhead Distribution 33/11kV S/S
As is now
11 kV Overhead Distribution 33/11kV S/S
Fault here
As is now
11 kV Overhead Distribution 33/11kV S/S
Improvement Way
AR
AR
AR
AR
SE SE
SE
SE
11 kV Overhead Distribution
33/11kV S/S
Improvement Way
AR
AR
AR
AR
SE SE
SE
SE
11 kV Overhead Distribution
33/11kV S/S
Improvement Way
AR
11 kV Overhead Distribution 33/11kV S/S
Improvement Way
AR
AR
AR
AR
SE SE
SE
SE
11 kV Overhead Distribution
33/11kV S/S
Improvement Way
AR
AR
AR
AR
SE SE
SE
SE
11 kV Overhead Distribution 33/11kV S/S
Improvement Way
AR
AR
AR
AR
SE SE
SE
SE
Impact of Automation System
Power Restored
to Customers on
Healthy Sections
of FeederFault
Occurs
Customer
Reports
Outage
Travel Time
Fault
Located
Investigation
& Patrol TimeTime to Perform
Manual Switching Repair Time
Feeder
Back to
Normal
5 – 10
minutes
15 – 20
minutes
10 - 15
minutes
45 – 75
minutes
15 – 30
minutes
1 - 4
Hours
Power Restored
to Customers on
Healthy Sections
of FeederFault
Occurs
Customer
Reports
Outage
Travel Time
Fault
Located
Investigation
& Patrol TimeTime to Perform
Manual Switching Repair Time
Feeder
Back to
Normal
5 – 10
minutes
15 – 20
minutes
10 - 15
minutes
45 – 75
minutes
15 – 30
minutes
1 - 4
Hours
Fault
Occurs
Customer
Reports
Outage
Travel Time
Fault
Located
Investigation
& Patrol TimeTime to Perform
Manual Switching Repair Time
Feeder
Back to
Normal
5 – 10
minutes
15 – 20
minutes
10 - 15
minutes
45 – 75
minutes
15 – 30
minutes
1 - 4
Hours
minutes Hoursminutesminutes Hoursminutesminutes Hoursminutes1 – 2
minutes
1 – 2
minutes
1 – 2
minutes
Field
Crews
On- Scene
15 – 30
Feeder
Back to
Normal
Power Restored
to Customers on
Healthy Sections
of Feeder
Travel Time Repair Time
1 - 4 5 - 10
Patrol
Time
Customer
Reports
Outage
Fault
Occurs
Field
Crews
On- Scene
15 – 30
Feeder
Back to
Normal
Power Restored
to Customers on
Healthy Sections
of Feeder
Travel Time Repair Time
1 - 4 5 - 10
Patrol
Time
Customer
Reports
Outage
Fault
Occurs
Field
Crews
On- Scene
15 – 30
Feeder
Back to
Normal
Power Restored
to Customers on
Healthy Sections
of Feeder
Travel Time Repair Time
1 - 4 5 - 10
Patrol
Time
Customer
Reports
Outage
Fault
Occurs
Without Automation
With Automation
Reliability Performance Indices • With moves toward deregulation and open
competition, access to accurate and timely outage information is critical in order to maximize operational efficiency, minimize customer complaints, and maintain electric system reliability.
• In this respect, it is common practice to track and benchmark reliability using standard performance indices such as CAIDI, SAIFI, and SAIDI.
• These indices serve as valuable tools to compare utility reliability performance, but care must be taken to ensure they are being calculated in the same manner.
Index Definitions • System Average Interruption Frequency Index
• System Average Interruption Duration Index
• Customer Average Interruption Duration Index
Served Customers ofNumber Total
onsInterruptiCustomer ofNumber TotalSAIFI
Served Customers ofNumber Total
Durationson InterruptiCustomer SAIDI
onsInterruptiCustomer ofNumber Total
Durationson InterruptiCustomer CAIDI
Interruptions/Customer/Yr
Minutes/Customer/Yr
Minutes/Interruption/Yr
Reliability Benchmarking Example
Another Benchmark Example
CEM HKE CLP
ConEd
EnergyAustralia
ETSA UtilitiesWestern Australia
0.00
20.00
40.00
60.00
80.00
100.00
120.00
140.00
SA
IDI
in
Min
ute
s/C
ust
om
re/Y
ear
SAIDI Comparison
CEM
ConEd
EnergyAustralia
ETSA Utilities Western Australia
0.00
0.20
0.40
0.60
0.80
1.00
1.20
SA
IFI
in #
Tim
es/C
ust
om
er/Y
ear
SAIFI Comparison
Some European Comparisons Survey Per Year 2004
Possible SAIDI Variations by Zone
Feeder Automation • Rather than rely on manual switching by field crews,
automated feeder devices can be used to – Detect and isolate a faulted feeder section
– Restore power to customers upstream of the fault
– Restore power to customers downstream of the fault
• Such feeder automation can be implemented using different strategies, e.g., those that depend on – Automated devices operating locally without
supervision
– Devices controlled remotely by an automation system
Possible SAIFI Variations by Zone
Example Strategy Study Using SAIDI
0.0
1.0
2.0
3.0
4.0
0 1 2 3 4
Cost (MUSD)
SA
IDI
(hr/
yr)
Base
Fuse Saving
Ag
gre
ss
ive
Sw
itc
hin
g
New
Lin
e D
evic
es
New
Fee
de
r
Au
tom
ati
on
Rec
on
fig
ura
tio
n
FC
Is
Tre
e W
ire
0.0
1.0
2.0
3.0
4.0
0 1 2 3 4
Cost (MUSD)
SA
IDI
(hr/
yr)
Base
Fuse Saving
Ag
gre
ss
ive
Sw
itc
hin
g
New
Lin
e D
evic
es
New
Fee
de
r
Au
tom
ati
on
Rec
on
fig
ura
tio
n
FC
Is
Tre
e W
ire
Law of Diminishing Return
Reliability Improvement vs. Cost
0
500
1000
1500
2000
2500
3000
0 20000 40000 60000 80000 100000
Cost
Cu
st
Ou
tag
e M
inu
tes
Imp
rov
em
en
t
• Stage 2: – Develop strategy implementation scheme
– Select vendors
• Stage 3: – Supply and install distribution system upgrades
including automation equipment
– Supply and install control center facilities
– Supply, install, and commission DAS including remote terminal units and communications equipment
• Stage 4: Determine and implement capacity building program to support systems and business processes resulting from the upgradation project.
Reliability Improvement implementation
VH
MUSS
Axis HT SJM RMUKrubara Sangha RMU
Sagar RMUJanatha RMUW5 SD
Arya Vysya
Mourya
GLM
KPC
Churchill
A.R Circle
brigade Plaza
Jwala
Complex
Keshava
Nivasa
Brigade
Majestic
SJM HT
Palmodi
UBI
Vectra
Pancha
Rathna
Heritage
Adarsh Inn
Lakshmi
Rajamma
Simha
Era
Tallam
Sagar
Adigas
Central
CollegeCTO
Green House
Arya Vysya
Janatha Bazaar
KamatFP
Bajaj
Sapna
Sukh Sagar
Park RMU Syndicate RMU
Vijaya
Samraj
KamatHT
S.N Bazaar
Sukh Sagar
HT (New)
Sukh Sagar
HT(Old)
Janatha Bazaar
From Syndiate RMU OD (F20 of 'A' station)
Single Linde Diagram of F1 Feeder of 'A' Station (W4 SD)
F01F08
F06
F11
M
M
M
A
M
Sn
V
A
M
V
A
M
U
S
S
Single Line Diagram showing automation component
SS#1 SS#
2
AUTOMATION OF MANUAL SYSTEMS
Automate existing Equipment
Introduce scada ready components
• Switches
• RMU
• Auto Reclosures
• Sectionalisers
• Fault Passage
Indicators
lV. Remote-controlled switch network
Normally-open point
Telecontrolled Switches
Substation CBs
33/11kV Substation
10km
10km
12.5km
10km
10km 10km
10km
10km
10km 10km
10km
10km
10km
10km
17.5km
10km 10km
20km
Feeder 1
Feeder 2 Optical Fiber
Fault
Control
room
Communications
Normally-open point
Sectionalisers
Substation CBs
33/11kV Substation
10km
10km
12.5km
10km
10km 10km
10km
10km
10km 10km
10km
10km
10km
10km
17.5km
10km 10km
20km
Feeder 1
Feeder 2
Radio Communications
Control
room
Fault
lV. Sectionalizer network
Normally-open point
Feeder Automation Sectionalisers
Reclosers
33/11kV Substation
10km
10km
12.5km
10km
10km 10km
10km
10km
10km 10km
10km
10km
5km
5km
5km
5km
10km
7.5km
5km
5km
5km
5km
7.5km
12.5km
Feeder 1
Feeder 2
Fault
Control
room
FA
tim
e Protection Direction
Changes
Recloser
Trips
Tie closes
FA Sectionalises
lV. Feeder automation network
Reliability Analysis
• DRAKE (Distribution Reliability Analysis – KEMA) is a software tool that allows a reliability assessment model to be defined and then used to – Design new systems to meet explicit reliability targets
– Identify reliability problems on existing systems
– Test the effectiveness of reliability improvement projects
– Determine the reliability impact of system expansion
– Design systems that can offer different levels of reliability
– Design systems that are best suited for performance based rates
Results of a Reliability Analysis
• On a feeder, system, and customer basis generate results such as the expected number of – Momentary interruptions per year
– Sustained interruptions per year
– Hours of interruption per year
– Protection device operations per year
– Switching operations per year
Modeling Capabilities in Reliability Analysis
• Different types of faults (3-phase, line-to-ground, etc.) • Feeder automation (e.g., Fault Location, Isolation, and
System Recovery) • Fuse saving and fuse clearing • Single-phase reclosing and lockout • Imperfect protection coordination • Post-fault feeder reconfiguration • Capacity limitations during feeder reconfiguration • Equipment bypass during system reconfiguration • Impact of weather • Changes in operational practices during storms • Reliability optimization algorithms
Sample Screen Captures
Visualization of Results
Custom Histograms
Reliability IndicesRisk Assessment
Custom Graphs
Query Searches on Data and Results
DAS functions Network Connectivity Analysis (NCA)
State Estimation (SE)
Load Flow Application (LFA)
Voltage VAR control (VVC)
Load Shed Application (LSA)
Fault Management and System Restoration
(FMSR)
Loss Minimization via Feeder Reconfiguration
(LMFR)
Load Balancing via Feeder Reconfiguration
(LBFR)
Operation Monitor (OM)
• Distribution Load forecasting (DLF)
Distribution Network (DA) Model The Distribution Automation should represent the various components of the Utilities distribution
system and include all the primary substation feeders, distribution network and devices with
possible islands, which may be formed dynamically. The following devices are represented in the
network model.
Power Injection points
Transformers
Feeders
Load (balanced as well as unbalanced)
Circuit Breakers
Sectionalizers
Isolators
Fuses
Capacitor banks
Reactors
Generators
Bus bars
Temporary Jumper, Cut and Ground
Meshed & radial network configuration
Line segments, which can be single-phase, two-phase, or three phase and make up a distribution circuit.
Conductors
Grounding devices
Fault detectors
IEDs
Operational limits for components such as lines, transformers, and switching devices
The database of the network model of the utility system can have interface with the GIS system of
the area for better visual decisions for crew management and asset information. The Customer
Interface Management can also integrate with the distribution automation system for effective
utilisation.
Network Connectivity Analysis (NCA) The network connectivity analysis function provides the connectivity between various network
elements. The prevailing network topology will be determined from the status of all the switching
devices such as circuit breaker, isolators etc that affect the topology of the network modelled.
NCA runs in real time as well as in study mode. Real-time mode of operation uses data acquired by
SCADA. Study mode of operation will use either a snapshot of the real-time data or save cases. NCA
can run in real time on event-driven basis.
The network topology of the distribution system will be based on
Tele-metered switching device statuses
Manually entered switching device statuses.
Modelled element statuses from DA applications. The NCA will be useful in determining the network topology for the following status of the
network.
Bus connectivity (Live/ dead status)
Feeder connectivity
Network connectivity representing S/S bus as node
Energized /de-energized state of network equipments
Representation of Loops (Possible alternate routes)
Representation of parallels
Abnormal/off-normal state of CB/Isolators
The NCA also assists the power system operator to know the operating state of the distribution
network indicating radial mode, loops and parallels in the network. Distribution networks which are
normally operated in radial mode; loops and/or parallel may be intentionally or inadvertently formed.
State Estimation (SE) The State Estimation (SE) is used for assessing (Estimating) the distribution network state. It shall assess loads of all network nodes, and, consequently, assessment of all other state variables (voltage and current phasors of all buses, sections and transformers, active and reactive power losses in all sections and transformers, etc.) in the Distribution network.
Load Flow Application (LFA) The Load Flow function shall provide real/active and reactive losses on:
Station power transformers
Feeders
sections
Distribution circuits including feeder regulators and distribution transformers, as well as the total circuit loss
Phase voltage magnitudes and angles at each node.
Phase and neutral currents for each feeder , transformers, section
Total three phases and per phase KW and KVAR losses in each feeder, section , transformer ,DT substation & for project area
Active & reactive power flows in all sections, transformers List of overloaded feeder, lines, busbars, transformers loads etc including the actual current magnitudes, the overload limits and the feeder name, substation name
List of limit violations of voltage magnitudes, overloading.
Voltage drops
Volt –VAR control (VVC) In electrical power system the reactive power can be generated at source generators or can be
injected at the substations through Volt-var systems. It is more appropriate to inject at substations
rather then producing then at generator points and transporting them over long distances. Any
power system always tries to optimise on the reactive power flow over their networks.
The coordination of voltages and reactive power flows control requires coordination of VOLT and
the VAR function. This function shall provide high-quality voltage profiles, minimal losses,
controlling reactive power flows, minimal reactive power demands from the supply network.
The following resources should be taken into account in any voltage and reactive power flow
control:
TAP Changer for voltage control
VAR control devices: switchable and fixed type capacitor banks.
Load Shed Application (LSA) The power delivery to the consumers is also bogged down with the Demand-Supply problems, with
demand being always higher than supply. The reasons for less Supply are several including the
faults, tripping of lines. In these situations the power system operator tries to distribute available
power through Shedding of loads to consumers over small definite periods till he tides over the
situation of loss of power.
The load-shed application helps to automate and optimise the process of selecting the best
combination of switches to be opened and controlling in order to shed the desired amount of load.
Given a total amount of load to be shed, the load shed application shall recommend different
possible combinations of switches to be opened, in order to meet the requirement. The despatcher
is presented with various combinations of switching operations, which shall result in a total
amount of load shed, which closely resembles the specified total. The despatcher can then choose
any of the recommended actions and execute them.
In case of failure of supervisory control for few breakers, the total desired load shed/restore will not
be met. Under such conditions, the application will inform the dispatcher the balance amount of load
to be shed /restore. The load-shed application runs again to complete the desired load shed /restore
process.
Fault Management & System Restoration (FMSR) Application
The availability of data related to the breakers/ switches and the level of The Fault current flowing
in the networks helps one to Manage & Restore the System in an event of fault. This application
helps to provide the assistance to the power system despatcher for detection, localisation,
isolation and restoration of distribution system after a fault in the system has occurred with the
help of operating through the supervisory control available on SCADA. The devices which help in
localisation & isolation of the fault includes Auto Reclosures(AR), Sectionalisers, Fault Passage
Indicators etc. The operation & characteristics of these devices are separately addressed in the
SCADA section.
Loss Minimization via Feeder Reconfiguration (LMFR)
The switching operation during fault and requirement to supply power through alternate feeders in
the distribution network modifies the feeder configuration topology. The information of network
topology and availability of adjacent feeder networks can be useful in right selection of feeders
with overall aim of reducing the line losses and maximum power delivery to consumers.
This function identifies the opportunities to minimize technical losses in the distribution system by
reconfiguration of feeders in the network for a given load scenario. The technical losses are the
losses created by characteristic of equipment & cable such as efficiency, impedance etc.
The function helps in calculation of the current losses based on the loading of all elements of the
network. The Telemetered values, which are not updated due to telemetry failure, can also be
considered by LMFR application based on arriving at the recommendations of LF Application. The
LMFR application can be utilised to have the various scenarios for a given planned & unplanned
outages, equipment operating limits, tags placed in the SCADA system while recommending the
switching operations.
Load Balancing via Feeder Reconfiguration (LBFR)
The discussions had on previous topic can be used for the Load Balancing via Feeder
Reconfiguration for the optimal balance of the segments of the network that are over & under
loaded. This helps in better utilization of the capacities of distribution facilities such as transformer
and feeder ratings.
The Feeder Reconfiguration Function can be used also to have a scenario on an overload condition,
unequal loadings of the parallel feeders and transformers, periodically or on demand in the
network by the despatcher. The system will help generate the switching sequence to reconfigure
the distribution network for transferring load from some sections to other sections. The LBFR
application can even consider the planned & unplanned outages, equipment operating limits, tags
placed in the SCADA system while recommending the switching operations.
The function helps in distributing the total load of the system among the available transformers and
the feeders in proportion to their operating capacities, considering the discreteness of the loads,
available switching options between the feeder and permissible intermediate overloads during
switching. The despatcher can have the options to simulate switching operations and visualise the
effect on the distribution network by comparisons based on line loadings, voltage profiles, load
restored, system losses, number of affected customers.
Load Forecast (LF) The Distribution Automation system keeps logging data periodically of the network. This historical
database and weather conditions data collected over a period can be used for prediction and to
have forecasting of the requirement of consumer loads. Generally there are two types of
forecasting that are resorted too.
Short-Term Load Forecasting (STLF) will be used for assessment of the sequence of average
electrical loads in equal time intervals, from 1 to 7 days ahead. The Long term forecasting is used
for forecasting load growths over longer durations. The fore casting techniques are based on
different forecasting methods such as:
Autoregressive.
Least Squares Method
Time Series Method.
Neural Networks.
Kalman filter
Weighted Combination of these method
Feeder Automation Philosophy
• Feeder automation makes use of various devices to reconfigure/switch feeders under normal and abnormal operating conditions, devices such as – Circuit breakers – Line reclosers/regulators – Group operating switches/load break
switches
• As to be discussed these devices are used within the context of different automation philosophies
Example of Automated GOS
Example of Automated Load Break Switches/Line Reclosers
SF6 LBS
Vacuum LBS
Air-Break LBS
Line Recloser
Example of RMU (Pad-Mounted Switches)
Generally, if not automation ready, can be retro-fit with motor
or solenoid operating mechanism
Automated Feeder Switching
• Automated feeder switching can involve the fore-mentioned devices in such a way that – They operate in a coordinated, but
unsupervised manner
– Alternatively in a supervised (integrated) manner, i.e., monitored and possibly controlled by a computer system located for example at a substation or control center
• Remote operation can be manual, semi-automatic, and/or fully automatic (no manual intervention)
Feeder Automation Architectures
• Standalone Automatic Switches – Reclosers, sectionalizers
• Centralized System – Switches controlled by central DAS/DMS
• Substation Centered Approach – Substation unit controls switches on associated
feeders
• Peer-to-Peer Arrangement – Groups of switches communicate to determine
appropriate switching actions
Centralized Feeder Automation
• System controlled by central DAS – Acquire data from field
devices
– Process data in DAS
– Issue supervisory control commands
• Can be manually, semi-automatic, or fully-automatic
Comm. TowerWorkstation
Centralized Feeder Automation (Conceptual Block Diagram
SCADA Server
DAS/DMS ServerFeeder Models
Power Flow
Load Estimator
Topology Processor
Feeder Automation
Switch Order
Management
Substation
and Feeder
Devices
Fault indicator
status, currents,
voltages
Device Control
Commands
Geogaphic
Information
System
(GIS)
Real-Time
Data
Dispatcher ConsoleEquipment
Status and
Loading
Switching
Actions
Central
DAS/DMS
Feeder
Equipment
Data, Topology
Information
Central Scheme Pro’s & Con’s
• Pro’s – Dispatchers retain control – Dispatchers are always informed – Considerably more operating flexibility
• Fewer restrictions (e.g., number of switches controlled) • Better ability to handle abnormal situations
– No “unnecessary” switching – Additional functionality possible
• Non-outage switching • Feeder load balancing
• Con’s – Requires DAS – Requires extensive communications infrastructure – Requires distribution system (network) models to be created
and maintained
Substation Centered Approach
• System controlled by substation PLC or RTU – Acquire data from field
devices – Process data in
substation master – Issue supervisory control
commands as needed to field devices
• Can be manual, semi-automatic, or fully-automatic
Comm. Tower
Local HMI
RTU/PLC
SCADA EMS
Substation
OPTIO
NAL
Substation Centered Pro’s and Con’s
• Pro’s - Fairly easy to set up and maintain - May or may not require electrical feeder models - May be interconnected to a central DAS, but can
operate independently - Lower cost alternative
- Con’s - Difficulty in handling complex situations as in case
of heavily loaded feeders where load must be split up
- Limited number of switches controlled - Requires substation/feeder communications
Peer-to-Peer Approach
• Network of Distributed Controllers
– Work as a team – Acquire “local” data via
local sensors – Acquire “remote” data
via “peer-to-peer” communications with other controllers
– Process data locally – Open/close associated
switch as needed • Primarily intended for
fully-automatic operation
Peer-to-Peer Pro’s
• Pro’s – Does not require
• Central SCADA system
• Feeder models supported by GIS interface
• Extensive communications infrastructure
– Costs less than central approach – Primary application is FLISR, but not limited to this
• Can be fully functional feeder SCADA system
Peer-to-Peer Con’s
• Con’s
– Lack of operator visibility and control • Can add SCADA interface (most utilities do!)
– Communication difficulties • Peer-to-peer communications among pole top units can be a
challenge!
– Costs more than substation centered approach
– Some “unnecessary” switching involved • Switches in a team open regardless of fault location
• Then close back in as necessary
• May fail to close? Extra “mechanical” operations?
Feeder Automation Applications
• Fault Location, Isolation, and Service Restoration – Can detect and locate fault, isolate the faulty section,
restore power to “healthy” feeder segments
• Load Shedding – Can shed one feeder section if necessary
• Cold Load Pickup – Can pick up feeder load one section at a time
• Feeder Reconfiguration – Can balance load between feeders and reduce losses
• “Intelligent” Substation Bus Transfer – Can transfer load to another substation following
transformer failure
R
T
U
R
T
U
Primary Plant
Interface
KEY ELEMENTS of DAS
Data & Control
Pathway
Communications
Master
Station Substation
1 2
3
4 Optical Fibre,
Cable
Radio
Microwave
R
T
U
1
2 RTU
3
4
Communications
Master Station
Line
Reporting
Analysis
5
5 Control Room,
Corporate Usage
Control Room
Operators
Outage Analysis
Operational analysis,
decisions, issue controls
5
RTU
COMMUNI-
CATIONS
SCADA
DMS
User
Interface
Data
Acquisition
DMS Applications
SCADA
Functions
SCADA Platform Environment
Maintenance Management
Decision Support Systems
OMS Crew Management
GIS
Other Applications
DAS Functional/Architectural Overview
Corporate Data Accessibility and
Availability
Future
State
Analysis
Crew Management
Outage
Management
Outage Analysis
Outage Reporting
IVR
Reports and
History
Operational
Diagrams
Switching
Management Switching
Planning
Asset
Maintenance CIS
SCADA
Network
Operational
Model
NOM
Updates to
Network Model
and Diagrams
Calls
Planning ERP, GIS
Corporate
Asset Data
and
Model
Design
r/t state r/t state
Current State
Analysis
(Incorporates Load
Modelling and
Network Analysis
Typical Distribution Control Room environment
Future
State
Analysis
Crew Management
Outage
Management
Outage Analysis
Outage Reporting
IVR
Reports and
History
Operational
Diagrams
Switching
Management Switching
Planning
Asset
Maintenance CIS
SCADA
Network
Operational
Model
NOM
Updates to
Network Model
and Diagrams
Calls
Planning ERP, GIS
Corporate
Asset Data
and
Model
Design
r/t state r/t state
Current State
Analysis
(Incorporates Load
Modelling and
Network Analysis
Typical Distribution Control Room Environment
DAS
DAS Vision • Conceptual Architecture
– The DAS system will have a distributed architecture with an ability to support Control Centres and remote data acquisition
– It will incorporate rapid disaster recovery capability including a backup control centre. • Scope of Control
– There will be a designed level of System-Wide DAS Control capability e.g., Load switching, Fault Location Isolation and System Restoration (FLISR)
• Performance and Expandability – The system will provide operationally acceptable performance as its domain of influence
grows or changes. It will support expansion as operational or corporate needs grow or change
• Interfaces and Integration – The DAS will provide for relevant interfaces necessary to support the suite of
applications and in accord with the principle of elimination of duplication in particular data entry
• Corporate Data Visibility – The DAS will provide for corporate visibility and accessibility to SCADA/DMS data
• Operational Flexibility – The DAS will provide flexible support of roles and responsibilities of personnel
(Operators, System Engineers, Maintainers, Crews, Crew Managers, etc.) • DMS Applications
– The DAS will include a DMS suite of capabilities within its bounds of influence – Capability building is core to its success,
DAS Functional Requirements
• Core DAS+
– Protocols (IEC 60870-5-101, IEC 60870-5-104, TASE.2)
– Distributed Data Acquisition Nodes
– Distributed Control Desks (Main Control Room, Backup CR, Remote Consoles)
– Various Communications Interfaces
– Data Acquisition (Status, Analogues)
– Historical Data (what retention, what storage rates, accessibility?)
– Alarming (what is intended to be the response of the BESCOM Operator?)
– Provides Primary UI to SCADA & DMS applications
• Data Volumes, Navigation, Browser Access need to be considered
– Disaster Recovery Management
• Regular exercise of backup capability
– Possible Import of Data from Corporate Asset Data – GIS, other??
– Possible integration/interface with Corporate Distribution applications
• Customer Information System (CIS) / Billing System
• Interim Outage Management System (OMS) (Phase 1)
DAS Functional Requirements (cont’d)
• DAS Core – Network Operational Model & tools to build + incrementally update the
NOM from corporate data sources • Connectivity • Electrical Attributes • ‘Intelligent’ Views (Operational Diagrams)
– Maintain current network state in NOM • Outage Management
– Analysis, grouping, ungrouping outage reports – Inferring the source/cause of outages – Providing data to call centre & IVR with respect to unplanned and
planned outages – Dispatching outage jobs to work management – Tracking outages to completion – Deriving outage statistics (CAIDI, CAIFI, SAIDI, SAIFI)
DAS Functional Requirements (cont’d)
• Switching
– Planning/scheduling all network switching – linked to work management
– Planning detailed switching steps - obeying processes + rules
– Support the plan/check/approval process + access permit process for work in progress
– Record the execution of switching actions and record network state in NOM
– Support processes to update NOM as network asset added/removed/changed
• Distribution Network State Analysis
– Current State
• Live/Dead Analysis (including effect of jumpers, cuts, and grounds)
• Check proposed switching
• Routinely check impact of selected contingencies
– Future Possible State
• Develop/check proposed switching
• Check worst case scenarios
• Check potential contingencies
• Crew Management
– Assign and close out trouble tickets (e.g., allows statistics to be maintained)
– Track field resources and facilities return to service.
Example of a Recent DAS architecture
- Ergon Energy, Queensland Australia
Ergon Energy Overview
• 68 connection points to the TNSP
• 33 Ergon Energy owned generating stations (diesel/wind/solar) which supply isolated distribution
• Total distribution asset value is approximately $3 billion
• Includes 140,000km of distribution lines and more than 400 Zone Substations.
ABB Support
ABB Houston
DMZ LAN
IS&R LAN
SCADA LAN
FCFC FCFC
SAN Switches
RAID Array
AlphaServer DS 25
2CPU
4GB Memory
288GB Disk
AlphaServer DS 25
1CPU
4GB Memory
432GB Disk
Oracle IS&R Servers
NETWORK MANAGER
Applications Servers
ControllersRockhampton
Control Centre
Corporate Data Network
C&DS Users
Rockhampton Master
Station (RMS)
SCADA Wide Area Network
ICP B/O Panels
SBS PCI
ExpansionSBS PCI
Expansion
ICP B/O Panels
SBS PCI
ExpansionSBS PCI
Expansion
ICP B/O Panels
SBS PCI
ExpansionSBS PCI
Expansion
ICP B/O Panels
SBS PCI
Expansion
SBS PCI
ExpansionSBS PCI
Expansion
SBS PCI
Expansion
ICP B/O Panels
SBS PCI
ExpansionSBS PCI
Expansion
ICP B/O Panels
SBS PCI
ExpansionSBS PCI
Expansion
ICP B/O Panels
SBS PCI
ExpansionSBS PCI
Expansion
ICP B/O Panels
SBS PCI
Expansion
SBS PCI
ExpansionSBS PCI
Expansion
SBS PCI
Expansion
DMZ LAN
IS&R LAN
SCADA LAN
FCFC FCFC
SAN Switches
RAID Array
AlphaServer DS 25
2CPU
4GB Memory
288GB Disk
AlphaServer DS 25
1CPU
4GB Memory
432GB Disk
Oracle IS&R Servers
NETWORK MANAGER
Applications Servers
Rockhampton
DAFE
Operational
Communicaitons
Network
ControllersGarbutt
Control Centre
Garbutt Master
Station (GMS)
ICP B/O Panels
SBS PCI
ExpansionSBS PCI
Expansion
ICP B/O Panels
SBS PCI
ExpansionSBS PCI
Expansion
ICP B/O Panels
SBS PCI
ExpansionSBS PCI
Expansion
ICP B/O Panels
SBS PCI
Expansion
SBS PCI
ExpansionSBS PCI
Expansion
SBS PCI
Expansion
Townsville
DAFE
Operational
Communicaitons
Network
Operational
Communicaitons
Network
ICP B/O Panels
SBS PCI
ExpansionSBS PCI
Expansion
ICP B/O Panels
SBS PCI
ExpansionSBS PCI
Expansion
ICP B/O Panels
SBS PCI
ExpansionSBS PCI
Expansion
ICP B/O Panels
SBS PCI
Expansion
SBS PCI
ExpansionSBS PCI
Expansion
SBS PCI
Expansion
Operational
Communicaitons
Network
ICP B/O Panels
SBS PCI
ExpansionSBS PCI
Expansion
ICP B/O Panels
SBS PCI
ExpansionSBS PCI
Expansion
ICP B/O Panels
SBS PCI
ExpansionSBS PCI
Expansion
ICP B/O Panels
SBS PCI
Expansion
SBS PCI
ExpansionSBS PCI
Expansion
SBS PCI
Expansion
Operational
Communicaitons
Network
ICP B/O Panels
SBS PCI
ExpansionSBS PCI
Expansion
ICP B/O Panels
SBS PCI
ExpansionSBS PCI
Expansion
ICP B/O Panels
SBS PCI
ExpansionSBS PCI
Expansion
ICP B/O Panels
SBS PCI
Expansion
SBS PCI
ExpansionSBS PCI
Expansion
SBS PCI
Expansion
Operational
Communicaitons
Network
Historian Users
Toowoomba
DAFE
Maryborough
DAFE
Mackay
DAFE
Cairns
DAFE
Internet
VPN Access
Powerlink Wide Area
Network
Remote Access
via PSTN
Remote Access
via PSTN
Ergon NOC
NOC Support
Network diagram for the distribution area
Network diagram for the Town of Rockhampton showing streets and transformers
Control Centre Facilities
• Layout of work areas
• Allowance for Engineering/administration
• Allowance for meeting/visitors
• Wallboard
• Equipment Room
• UPS
• Air Conditioning
• Communications equipment, access, distances
• Corporate connectivity
Ergon Energy Australia - Distribution
Comed USA – Distribution Chicago
Typical System Architecture for Local Control Centre at Distribution Substations
Numerical
Relays
IEDs
Feeder 1 Feeder 2 Feeder 12
IEC 60870-5-104
to Control Centre
Serial interfaces of 3rd party relays
on IEC-103 protocol
IEC 61850
FO Link
Feeder 13 Feeder n
ET Switch
Laptop
Field Signals DI/ DO/
AI
System Configuration for Data Concentrators
SICAM
AK1703 Data
Concentrator
HMI (LCC)
Inverter
RTU
Electro
Mechanical
Relays
IEC 61850 Substation Architecture
RTU at Substation- ABB SPIDER-200
IBM Compatible
Modem
Modem
COMMUNICATION LINK
Radio - TDMA
Har
d W
irin
g
.01GB Thin net LAN
DEC
Alpha
Servers
FEP
Poll
Data
Repeaters Limited
applications
Substation Switch yard
Quality Assurance
Introduction
• SCADA / DMS systems and components needs to undergo various
tests and inspection methodologies as per well-established national
and international standards.
• The testing ensures the procured systems / components meets the
safety, reliability and other requirements to ensure proper
functioning of the system.
Standards for SCADA / DMS
• Any large utility with an on going SCADA program and which over
time intends to install a number of discrete SCADA systems, must
eventually integrate these systems.
• The SCADA program will involve multiple vendors over time and
they will face problems due to the SCADA industry's use of
proprietary hardware, software and communications protocols.
• A smaller utility may be able to install in one go a SCADA system
that encompasses the majority of their operations.
- The utility will buy a proprietary system and rely on that vendor
for continued upgrades and support.
- But this approach will be cost intensive and highly dependent on
the vendor support.
• The prime difference between these two situations is that the
smaller utility can standardise by installing a single system whereas
the larger utility is necessarily faced with a lengthy program, with
relatively small expansions at any time (compared to the overall
system).
Standards for SCADA / DMS
• To ensure interoperability and to protect long term investment over
technology obsoleteness, it is essential to adopt standardized
products.
• It will ensure availability of quality products at competitive prices
from multiple vendors.
• Communications protocols are the major area requiring standards,
and there are a number of alternatives.
• Another aspect of standards is that they cannot be too rigid, but
must still leave flexibility for systems to add new functionality or
select certain options.
• Many standards come with both mandatory requirements and
optional selections, as well as with “extension rules” for expanding
the standards in a consistent manner for new functions.
• This helps to address a few vendor-specific requirements or utility-
specific requirements, as well as the flexibility to meet unforeseen
requirements in the future.
Standardizing Bodies
There are many national and international standardizing bodies:
– International Electro technical Commission (IEC)
– IS (Indian Standard)
– Institute of Electrical and Electronics Engineers (IEEE)
– American National Standard Institution (ANSI)
– British Standards (BS)
– European Committee for Electro technical Standardization
(CENELEC) etc
Protocols
• Modbus communication protocol is extremely used in process
instrumentation. Even though it is used in power sector, it is not
amenable for wide power sector automation requirements.
• DNP3 (Distributed Network Protocol) is a set of communication
protocols used between components in process automation systems
and is emerged from the electricity industry.
• RTU programming standards is IEC-61131-3 programming
languages. These have been developed for PLC programming, and
are increasingly being mandated for use by large manufacturing
concerns.
Commonly Referred Standards
RTU – The main component used for SCADA applications:
IEC 60870-5 SER Telecontrol Equipment and Systems –
Part 5: Transmission Protocols
IEC 60870-5-1 Transmission Frame Formats
IEC 60870-5-2 Data Link Transmission Services
IEC 60870-5-3 General Structure of Application Data
IEC 60870-5-4 Definition and Coding of Information Elements
IEC 60870-5-5 Basic Application Functions
IEC 60870-5-6 Guidelines for conformance testing for
IEC 60870-5 companion standards
IEC Technical Committee 57 has also published following companion
standards for telecontrol equipment:
IEC 60870-5-101 Transmission Protocols, companion standards
especially for basic telecontrol tasks
IEC 60870-5-102 Companion standard for the transmission of
integrated totals in electric power systems (this standard is not
widely used)
IEC 60870-5-103 Transmission Protocols, Companion standard for
the informative interface of protection equipment)
IEC 60870-5-104 Transmission Protocols, Network access for IEC
60870-5-101 using standard transport profiles
Substation Automation System (SAS)
IEC 61850 SER Communications Networks and Systems in
Substations
- Technical report / standard series are applicable to substation
automation systems.
- This standard defines the communication between intelligent
electronic devices in the substation and the related system
requirements.
Inter-Control Center Communication Protocol (ICCP)
• IEC 61870-6 Series Telecontrol equipment and systems - Part 6:
Telecontrol protocols compatible with ISO standards and ITU-T
recommendations.
• ICCP or IEC 60870-6/TASE.2 (Telecontrol Application Service
Element 2) is being specified by utility organizations throughout the
world to provide data exchange over wide area networks (WANs)
between utility control centers, utilities, power pools, regional control
centers, and Non-Utility Generators.
ICCP Functionality
Basic ICCP functionality is specified as “Conformance Blocks”. The objects that are used
to convey the data are defined in various parts of IEC 60870-6.
• IEC TC 57 WG3 also generated standards for telecontrol protocols compatible with
ISO standards and ITU-T recommendations.
These standards include:
– IEC 60870-6-1 Application context and organization of standards
– IEC 60870-6-2 Use of basic standards (OSI layers 1–4)
– IEC 60870-6-501 TASE.1 Service definitions
– IEC 60870-6-502 TASE.1 Protocol definitions
– IEC 60870-6-503 TASE.2 Services and protocol
– IEC 60870-6-504 TASE.1 User conventions
– IEC 60870-6-601 Functional profile for providing the connection-oriented
transport service in an end system connected via permanent access to a packet
switched data network
– IEC 60870-6-602 TASE transport profiles
– IEC 60870-6-701 Functional profile for providing the TASE.1 application service
in end systems
– IEC 60870-6-702 Functional profile for providing the TASE.2 application service
in end systems
– IEC 60870-6-802 TASE.2 Object models
DMS & CIM Standards
• IEC 61968 Series Application integration at electric utilities - System
interfaces for distribution management
• IEC 61968 is a series of standards under development that will define
standards for information exchanges between electrical distribution
systems. These standards are being developed by Working Group 14 of
Technical Committee 57 of the IEC (IEC TC 57 WG14).
The various standards published / under development are listed below.
• IEC 61968-1 – Interface architecture and general requirements
• IEC 61968-2 – Glossary
• IEC 61968-3 – Interface for Network Operations [NO]
• IEC 61968-4 – Interfaces for Records and Asset management [AM]
• IEC 61968-5 – Interfaces for Operational planning & optimization
[OP] [Under Development]
• IEC 61968-6 – Interfaces for Maintenance & Construction [MC] [Under
Development]
• IEC 61968-7 – Interfaces for Network Extension Planning [NE] [Under
Development]
• IEC 61968-8 – Interfaces for Customer Support [CS] [Under Development]
• IEC 61968-9 – Interface Standard for Meter Reading & Control [MR]
• IEC 61968-10 – Interfaces for Business functions external to distribution
management [Under Development]. This includes Energy management &
trading [EMS], Retail [RET], Supply Chain & Logistics [SC], Customer
Account Management [ACT], Financial [FIN], Premises [PRM] & Human
Resources [HR]
• IEC 61968-11 – Common Information Model (CIM) Extensions for
Distribution [Under Development]
• IEC 61968-12 – Common Information Model (CIM) Use Cases for 61968
[Under Development]
• IEC 61968-13 – Common Information Model (CIM) RDF Model exchange
format for distribution
• IEC 61968-14-1-3 to 14-1-10 – Proposed IEC Standards to Map IEC61968
and Multispeak Standards [Under Development]
• IEC 61968-14-2-3 to 14-2-10 – Proposed IEC Standards to Create a CIM
Profile to Implement MultiSpeak Functionality [Under Development]
DMS & CIM Standards contd…
Security standards
IEC 62351 series:
• IEC 62351 is a standard developed by WG15 of IEC TC57. This is developed for handling the security of TC 57 series of protocols including IEC 60870-5 series, IEC 60870-6 series, IEC 61850 series, IEC 61970 series & IEC 61968 series.
• IEC 62351-1 — Introduction to the standard
• IEC 62351-2 — Glossary of terms
• IEC 62351-3 — Security for any profiles including TCP/IP
• IEC 62351-4 — Security for any profiles including MMS (e.g., ICCP-based IEC 60870-6, IEC 61850, etc.).
• IEC 62351-5 — Security for any profiles including IEC 608705 (e.g., DNP3 derivative)
• IEC 62351-6 — Security for IEC 61850 profiles.
• IEC 62351-7 — Security through network and system management.
• IEC 62351-8 — Role-based access control.
Other Standards
IEEE C37.1-2007 Standard for SCADA and Automation Systems
• This standard applies to, and provides the basis for, the definition,
specification, performance analysis, and application of systems used
for supervisory control data acquisition or automatic control or both,
in attended or unattended electric substations, including those
associated with generating stations; and power utilization and
conversion facilities.
• The standard is generic and comprehensive enough to cover the
most of the aspects of system design, interface & processing
requirements and environmental requirements.
DNP 3.0:
• The main use of this standard is in utilities such as electric and water companies.
• It was developed for communications between various types of data acquisition and control equipment.
• It is primarily used for communications between a master station and RTUs or IEDs.
• The DNP3 protocol is also referenced in IEEE1379-2000, which recommends a set of best practices for implementing modern SCADA Master-RTU/IED communication links.
• The IEEE adopted DNP 3.0 as IEEE 1815-2010 in the year 2010.
• The Indian standard for Supervisory Control and Data Acquisition (SCADA) System for Power System Applications is IS 15953- 2011. This standard covers generic requirements of Power System SCADA.
TESTING AND INSPECTION
TESTING
• Testing on automation components is conducted to evaluate the system's compliance with its specified requirements.
• Testing is done at various levels and purposes/applications.
• Testing is required:
- Throughout the development and use cycle (life cycle) of a system (product, process or service) and it is more rigorous, it is for evaluation.
- During design (simulation), fabrication, assembly,
transfer of technology & field use.
- By independent accredited test laboratories like CPRI, ETDC/ ERTL etc. generally for a third party certification.
- For marking purposes such as BIS, CE, UL and many
others.
Type test: Series of tests carried out on the samples of the same type having identical characteristics, selected by manufacturer to prove conformity with all the requirements of the standard.
• Automation components shall conform to the type tests.
• A complete integrated unit shall be tested to assure full compliance with the functional and technical requirements of the Specification including functional requirement.
• The testing sample shall include one of each type of cards/modules and devices.
• Type testing shall be conducted in NABL accredited Labs or internationally accredited labs.
Test Nos. DESCRIPTION OF THE TEST
A FUNCTIONAL TESTS
Check for BOQ, Technical details, Construction & Wiring.
Check for database & configuration settings
Check the operation of all Analog inputs, Status input & Control output points.
Check operation of all communication ports.
Check for communication with master stations including remote database downloading from master
station
Check for auto restoration of RTU/FRTU on DC power recovery after its failure
Test for self-diagnostic feature
Test for time synchronization from Master
Test for SOE feature
End to end test (between RTU/FRTU & Master station) for all I/O points
Test for MODBUS protocol implemented for acquiring data from MFT/ transducers and updation time
demonstration in daisy chain configuration
Test for IEC 60870-5 -104,101 protocol implemented
Test for supporting other protocol
Table 1
Test Nos. DESCRIPTION OF THE TEST
A Test for operation with DC power supply voltage variation
Test for internal Clock stability
Test for Noise level measurement
Test for Control Security and Safety for Control outputs
Test for functionality/parameters verification of CMRs & Heavy duty trip relays
Test for data concentrator
Test for IED pass through
Test for SOE buffer & time data back up
Other functional tests as per technical specification requirements including features in support/ capability (for
future)
Test for DCPS of FRTU
Test for compliance of standards for bought items viz. CMRs, Heavy duty trip relays, MFT, weather sensor
etc.
Test for functionality/parameters for bought items viz. CMRs, Heavy duty trip relays, MFT, weather sensor
etc.
Test for test tools
Contd…..
Test Nos. DESCRIPTION OF THE TEST
B EMI/EMC IMMUNITY TESTS FOR RTU/FRTU
Surge Immunity Test as per IEC 60870-2-1
Electrical Fast Transient Burst Test as per IEC-60870-2-1
Damped Oscillatory Wave Test as per IEC 60870-2-1
Electrostatic Discharge test as per IEC 60870-2-1
Radiated Electromagnetic Field Test as per IEC 60870-2-1
Damped Oscillatory magnetic Field Test as per IEC-60870-2-1
Power Frequency magnetic Field Test as per IEC-60870-2-1
C INSULATION TEST FOR RTU/FRTU
Power frequency voltage withstand Test as per IEC 60870-2-1
1.2/50 μs Impulse voltage withstand Test as per IEC 60870-2-1
Insulation resistance test
D ENVIRONMENTAL TEST FOR RTU/FRTU
Dry heat test as per IEC 60068-2-2
Damp heat test as per IEC 60068-2-3
Routine Tests or Factory acceptance test (FAT):
Tests carried out on each sample to check
conformity with the requirements of the standard in
aspects which are likely to vary during production.
Acceptance Test or Site Acceptance Test (SAT):
Tests carried out on samples taken from a lot for
the purpose of acceptance of the lot.
Field Tests :
• After automation components are installed and commissioned in field, the Contractor shall carry out the field-testing.
Availability Tests:
• After field testing, automation components shall exhibit a 98% availability during test period.
• Availability tests shall be performed along with Master station.
• The RTU/FRTU shall be considered available only when all its functionality and hardware is operational.
• The non-available period due to external factors such as failure of DC power supply, communication link etc., shall be treated as hold-time & availability test duration shall be extended by such hold time.
Central Power Research Institute (CPRI) has full fledge
test facilities for type testing, IEC 61850, IEC 62056
protocol validation.
Utility IT Requirements
Conclusion
• SCADA / DMS improves the quality of service by reduction in number of outages & outage durations
• Quick isolation of faulty section & fast restoration of healthy section so that only least customers are affected during outage period.
• All data are available in real time and historical data archive for planning
Conclusion (contd.)
• Sharing of data with all stakeholders and MIS
• Though requires capital investment, but a good SCADA / DMS system implemented in a phased manner brings returns in a shorter period.
• All data are available in real time and historical data in archive for planning and other applications of utility
THANK YOU