SCADA
SYSTEM SOFTWARE
AND
APPLICATIONS
Jurisdiction of Load Despatch Centers
NLDC:
Apex body to ensure integrated
operation of National Power System
RLDC:
Apex body to ensure integrated operation
of power system in the concerned region
SLDC:
Apex body to ensure integrated operation
of power system in a state
HIERARCHICAL Setup…
NLDC
5 Nos. ERLDC
33 Nos.
WRLDC
SLDC
41 Nos. SUB LDC
1160 Nos.
RTU
NRLDC
SRLDC
NERLDC
SLDC
SLDC
SUB LDC
SUB LDC
RTU
RTU
TYPICAL CONTROL CENTRE
CONFIGURATION
SCADA /EMS
SERVER
ISR
SERVER
WORKSTATION
BASED
OPERATOR
CONSOLE
WITH TWO CRT
JUKE
BOX
DEVELOPMENT
CONSOLE
ICCP
COMMUNICATION
SERVER
LAN 1
FROM GPS
LAN 2
TIME SYNCH
SYSTEM
OPRATION
SCHEDULING
CONSOLE
DUAL CFE
COMMUNICATION
FRONT END
PROCESSOR
COMMUNICATION
FRONT END
PROCESSOR
SPLITTER
MODEM
VIDEO PROJECTION SYSTEM
/
MIMIC CONTROL BOARD
TO RTUs
TERMINAL SERVER
PERIPHERALS
NMS
CONSOLE
ROUTER
1
TO OTHER CONTROL CENTERS
CHENNEL
2X64KBPS
SOFTWARE LAYERS
OPERATING SYSTEM
HABITAT®
UTILITIES
APPLICATIONS
Operations
Training
Data
Acquisition
GENERATION
DISPATCHER
TRAINING
SIMULATOR
SCADA
Supervisory
Control
NETWORK
SCADA FUNCTIONS

RTU Data Acquisition

Supervisory Control

Data Exchange

Data Processing (Alarms,SOE,
Generalized Calculations)

Disturbance Data Collection

Historical Information Storage &
Retrieval (ISR)
DATA ACQUISITION
• Analog Measurement
Voltage - KV
Active Power - MW
Re-active Power – MVAR
System Frequency - Hz
• Digital Measurement ( Status / Indication )
Circuit Breaker Status
Isolator Status
Sequence Of Event ( SOE )
DATA ACQUISITION
Power System
Devices
R
Raaw
w
D
Daattt aa
C o nttt r olll s
RTU
MODEM
R
RTTU
U
D
Daattt aa
Communications
Front End
MODEM
S
SC
CA
AD
DA
A ddaatttaa
C
Coonntttrroolllss
SCADA DATABASE
DATA ACQUISITION
• The RTU collects data from the monitored
systems and transfers it to the front end.
• The front end receives data from the RTU,
formats the data, and then sends it to the SCADA
host CPU.
• The host CPU maintains the SCADA databases,
performs any necessary conversions, and checks
on the incoming data.
FRONT END FUNCTIONS
The Communication Front End handles all
normal data retrieval functions independently
of the SCADA host CPU.
– Converts RTU formats to RTU-independent hostformat.
– Allows “smart” scanning of a pre-selected set of
RTU measurements : Demand SCAN / Defined
SCAN
– Provides exception reporting.
– Sequences select-before-operate controls.
– Reduces CPU interrupt loading.
SCADA Host CPU Functions
• Primary task is to maintain SCADA & EMS
databases.
• Performs other functions:
–Converts raw data to engineering units.
–Performs limit checks.
–Processes alarms.
–Processes Calculations.
SCADA Displays
• There are three basic types of displays:
– Overview Displays
– Single Line Diagrams
– Tabular Displays
• A single display can contain all three display types,
each organized onto different views in the display
• Concept of Room
– A layout of viewports can be saved by a name
– Liking & ease of operation as per individual operator
CALCULATIONS
• Generalized calculations allow calculations to be
performed on points both analog & digital.
• A calculation can be dependent on the results of
another calculation.
• Special calculations can also be used to set up
special control sequences.
Human Machine Interface(HMI)
Display Features










X-Windows environment
Pop-up Menus
Dialog Boxes
Zooming
De-cluttering
Pop-up Pictures
Display Layers
Panning
Scroll Bars
Tabular Displays
REGIONAL OVERVIEW
400KV NETWORK
SINGLE LINE DIGRAM
Geographical Diagram-BSEB
GEOGRAPHICAL VIEW
LAYER CONCEPT
FLOW GATES
Angle Display
UI Meter
Events & Alarms
• EVENTS are happening all the time in the
POWER SYSTEM and the way we like to
interpret them decides the ALARMS
• All ALARMS are EVENTS but all
EVENTS are not ALARMS
• Events & alarms are presented to the Grid
operator in various forms depending upon
its type & severity.
Definitions
• Event - An event occurs when some notable
change happens at a single point in place/time.
• Alarm – An alarm is an unsolicited indication
from an application to the operator that a new
exception has occurred.
• System Activity Log - A data structure (linked list)
holding the textual messages formatted from the
exception messages sent to Alarm. The number of
logs and their contents are defined by the user.
Definitions
contd…
• Category - Each exception is assigned to a category.
Categories are used to assign priority and severity which
are used to group alarms within a list display and to order
Category and Location Alarm Line entries.
• Location - All exceptions are assigned to locations, or
geographic area occurrence, typically a substation.
Examples
• EVENT
Change in analog value, Change in the status
of an Isolator/breaker, Disk space reaching
60%
• ALARM
Breaker Opening, Limit Violation, Auto
Closure, Time Syn lost etc.
Events & Alarms-Presentation
•
•
•
•
Text Message
Category designated with the help of colors
Change of Color, Blinking etc
Change of Line Style(dotted for outage of the
element)
• Audible alarms
ALARMS-ANALOGS
MW/MVAR/MVA
• ALARM LIMIT-OPERATIONAL
• ALARM LIMIT-ALARMING
• ALARM LIMIT-EMERGENCY
ALARM LIMIT -MW
• ALARM LIMIT-OPERATIONAL
+/- 1.05*(1.732*V*I*O.8)
• ALARM LIMIT-ALARMING
+/- 1.10*(1.732*V*I*O.8)
• ALARM LIMIT-EMERGENCY
+/- 1.15*(1.732*V*I*O.8)
V-NOMINALVOLTAGE I-NOMINAL CURRENT
ALARM LIMIT -MVAR
• ALARM LIMIT-OPERATIONAL
+/- 1.05*(1.732*V*I*O.6)
• ALARM LIMIT-ALARMING
+/- 1.10*(1.732*V*I*O.6)
• ALARM LIMIT-EMERGENCY
+/- 1.15*(1.732*V*I*O.6)
V-NOMINALVOLTAGE I-NOMINAL CURRENT
ALARM LIMIT -MVA
• ALARM LIMIT-OPERATIONAL
+/- 1.05*(1.732*V*I)
• ALARM LIMIT-ALARMING
+/- 1.10*(1.732*V*I)
• ALARM LIMIT-EMERGENCY
+/- 1.15*(1.732*V*I)
V-NOMINALVOLTAGE I-NOMINAL CURRENT
OPERATIONAL
ALARMING
EMERGENCY
ALL LIMITS ARE
ENTERABLE
ALARM LIMIT –KV
• FORBIDDEN -ZONE
HIGH KV- 0.90* V
LOW KV - 0.5*V
i.e. FOR 400KV Level - 360 TO 20 KV
• HIGH
KV- 1.10* V
i.e. FOR 400KV Level - 440KV
ALARM LIMIT –HZ
• FORBIDDEN -ZONE
HIGH HZ- 47.5
LOW HZ – 2.5
HIGH
51.5
ALARM DIGITAL
Life Cycle of an EVENT
•
•
•
•
•
•
•
•
•
•
An Alarm client posts an event to the Alarm server.
Processing of the event leads the Alarm server to promote the event to
an alarm. The alarm is inserted in the list of alarms and in the logs.
The event is printed.
The alarm is associated with one or more tones in order to provide an audible
signal to the operators.
The event is archived in a file.
An operator acknowledges the alarm.
The Alarm server changes the state of the alarm from
“unacknowledged” to “acknowledged”. This entails moving the alarm
from its unack. lists to its ack. lists.
The client application is notified that the alarm has been
acknowledged.
The operator deletes the acknowledged alarm.
The alarm server removes the alarm from the alarm list.
SCADA as an Alarm User
Abnormal
Power
System
Event
SCADA
Application
Issue
Horn
Indication?
Acknowledgment?
Ack
Exception Display
Printing?
Alarm Utility
Acknowledgment?
Acknowledgment?
Logging?
net012.cvs
Alarm Synopsis Lines
Alarm List
Displays
System Activity Log(s)
and displays(s)
Hardcopy
Logger(s)
[Printer(s)]
Alarms Reporting
• Alarm Lists
-Alarm Summary/Priority
-Alarm Locations
-All Alarms
• Activity Logs
-System Activity Log
-Location Activity Log
-System Activity Archival
Sequence Of Event
• SCADA stores the list of events received from RTUs in
the System Activity Log on the basis of their reception
time in SCADA
• SOE also processes these events into a second list
where they are re-sequenced on the basis of time tags
stamped by the RTUs
– Events (status changes) can be time-stamped to 1
ms
at the source (RTUs)
– A SCADA display shows the re-sequenced list
(can be filtered)
– File dump can be produced upon operator request
• RTUs can be synchronized :
– By GPS (to less than 1 ms)
– By SCADA (to less than 10 ms)
SOE filtering
Filtering on station
Filtering on time
SOE in S900 RTU
• The S900 offers the possibility to memorise
signalling by master. The size of SOE files
is 1200 events when there is one master,
600 events for two masters and 400 events
for three masters.
• Each signalling is user database selectable
to be send or not to SOE file(s).
• This function is only avalaible when IEC
870-5-101 is used.
Historical Information
Management
(HIM)
Historical Information
Management(HIM)
 HIM environment architecture
Real Time Data
servers
ISR servers
NETWORK
Operator
consoles
Developer/2000
Slide
48
HIM Processing
 HIM sampler
Program running on the Data servers. It collects data periodically (5
min.) sensing all the changes from all the HABITAT databases (e.g.
SCADAMOM, RTGEN, RTCA) and sends it to the HIM recorder.
 HIM recorder
Program running on the ISR servers. It is connected to the HIM sampler
by TCPIP, receives data from HIM sampler and store it in the relational
database (ORACLE based).
 Data Archiving/Retrieving
Runs on the ISR servers. It automatically archives data recorded in
oracle tables on to the optical disks (juke box) for long term usage. It
allows restoring of data from juke box to the relational database on user
demand.
Slide
49
HIM Data Flow
Real time data servers
ISR servers
Alarms & events data
ALARM
application
Relational
DATABASE
HIM
ALARM
HABITAT
databases
HIM
HIM
SAMPLER
RECORDER
System
data
Recording
definition
Retained
data
Reconstructed
data
Data
archival/Reconstruction
SQL*Net
DEVELOPPER
2000
Operator
consoles
50
Juke Box
HIM Data Types
Data Type
Analog
Accumulator
Status
Alarms & Events
Recording
speed
Retention
Period
5 minutes
1 hour
10 sec
5 minutes
15 days
2 months
2 months
2 months
Slide
51
HIM User Interface
Slide
52
HIM User Interface(Contd..)
Slide
53
HIM User Interface(Contd..)
Slide
54
HIM User Interface(Contd..)
Slide
55
HIM User Interface(Contd..)
Slide
56
Historical Data
Recording
(HDR)
Slide
57
HDR Overview
Scanner
Application
SCADAMOM
Database
Data Recording Function
File Maintenance
Function
Database Reconstruction
Function
Relationship between on-line SCADA system and three HDR functions.
Slide
58
HDR Data Flow
Permanent Storage
Recording
Function
Recording
Dir.
Reconstruction
Dir.
Reconstruction
Function.
File
Maintenance
How data moves between HDR directories.
Slide
59
TRENDING
• Graphical representation of DATA
• On-line - Duration as per configuration.
• Historical – In the form of daily snapshot.
System Support Group NERLDC
60
System Support Group NERLDC
61
PRESENTAION MANAGER
DISPLAY OBJECTS
 TRACES Traces are traditional two-dimensional graphs of two
variables
 Trace-Bar A histogram where each sample value is shown as a
rectangle whose height is equal to the Y value and width is equal
to the difference between succeeding X values
 Bar Graphs Bar graphs show multiple values plotted from a
common base line
 Pie Charts Pie charts show the relative percentage of each
display object value plotted vs. the sum of the total of all display
object values. There is always only one pie chart per track
Meters show a value in relation to a minimum and maximum
scale for a single instance in time
 Meters show a value in relation to a minimum and maximum
scale for a single instance in time
System Support Group NERLDC
62
Trend Curve & Pie Chart
DISPLAY OBJECT
TRACK
System Support Group NERLDC
64
Challenges- SCADA Systems
• Ensuring availability of correct data and total
observabilty of the Power System in real time.
• Ensure fail safe system functionalities on 24x7 basis.
• Implementation of Innovative techniques to ensure
situational awareness for the grid operator.
• Utilization of EMS functions to the maximum to
anticipate and analyse grid incidents.
• Growing network complexities need increased
automation in all the functions of grid. operation.
New Trends
• PMU/WAMS Systems being planned for enhanced
utilization & greater stability of the power system
network.
• High speed communication networks coming up to
ensure reliable & faster data in real time.
• Innovative techniques like contouring, GIS based
displays being introduced for improved Situational
Awareness.
• Web based Applications & Service Oriented
Architecture being introduced.
New Trends(Contd..)
• Increasingly open systems coming up tending
towards plug & play systems.
• With the major thrust on green energy, integration
of renewables gaining huge importance.
• Archived SCADA data getting high importance and
state of the art historians order of the day.
• Development of Intelligent EMS Applications
gaining momentum.
Voltage Contour
Devendra Kumar
DGM,ERLDC