industrial trianing[1]

Abstract

Development of nation depends upon electricity energy and at present scenario there is large gap

between electric generation and load. This gap can be filled with proper control, monitoring and

coordinating the distribution components at power sector. In this view, Automation of power

distribution system has increasingly been adopted by power utilities worldwide in recent years.

As part of its efforts to provide a more reliable supply to the customer and to enhance operational

efficiency. The automation of the power system can be achieved by SCADA. It is a boon to the

automation concept of dynamic technology. SCADA refers to “SUPERVISORY CONTROL &

DATA ACQUISITION”.

Karnataka Power Transmission Corporation Limited (KPTCL) has undertaken steps to automate

existing substation and new substation by use of most advanced controlling and monitoring

technology ABB SCADA. Project was conceived in the year 2002, tenders floated in the year

2006 and project awarded to M/S ABB in December 2006. 220/110/11kV Receiving Station

Bijapur near Shivgiri Ukkali road and 110/11kV Receiving Station Bijapur at City were some of

the substations automated in this project.

Monitoring, controlling and coordinating the distribution equipments and trouble shooting at

fault are challenging task for engineers. These aspects make the power and energy system

engineers to know more about controlling of power system. In this view training has been taken

under Karnataka Power Transmission Corporation Limited (KPTCL) at Bijapur.

Karnataka Power Transmission Corporation Limited (KPTCL), presently with the help of

SCADA covers major generating stations and Independent Power Producers (IPP), receiving

stations ranging from 33kV to 400kV, collects data from all feeders from 11 KV to 400 KV,

upgrades information to Load Despatch Center (LDC). Real time data acquisition from all

interface points by SCADA, helps to perform energy billing, energy audit and Availability Based

Tariff (ABT) functions, and Sub-system to perform Open Access operations.

SCADA IN KPTCL

1. Introduction

Karnataka Power Transmission Corporation Limited is mainly vested with the functions of

Transmission of power in the entire State of Karnataka. To transmit and distribute power in the

State, it operates nearly 1042 sub-stations over 32,000 km of transmission lines with voltages of

66 KV and above. The 33 kV substations are owned and operated by the ESCOMs. To monitor

and control all substations remotely, KPTCL has undergone substation automation through

SCADA.

Substation Automation (SA) is a system to enable an electric utility to remotely monitor, control

and coordinate the distribution components installed in substation. High speed microprocessor

based Remote Terminals Units (RTUs) or Intelligent Electronic Devices (IEDs) are used for

substation automation and protection. These RTUs or IEDs are installed in strategic locations for

collection of system data and automatic protection of substation equipment [1]. Considering

economic aspect, instead of replacing all existing substation equipment for purpose SCADA,

KPTCL provides Remote Terminal Unit (RTU) at old substation for remote control. Thus at

110/11 kV substation Bijapur installed with RTU 560A. For new substations Substation

Automation System (SAS) is being used for automation. Thus at 220/110/11kV substation near

Shivgiri has both remote and local control by installing ABB’s IED 670. Data communication

protocols used for 110 kV substation are MODBUS, RS485, RS232, and for 220kV substation

are IEC61850, Optical Fiber Cable (OFC). Information collected from substations is

communicated through VSAT to Master Control Center (MCC).

In this training report effort has been made to explain SCADA implementation at 110/11kV and

220/110/11kVsubstations as both are different. Report consists of about SCADA technology,

SCADA connections at substation, equipment details used for SCADA, communication

protocols. Brief explanation on operation and working of Load Despatch Center is also included

in report. Thus concluding that SCADA has provided real time data acquisition, data sharing &

analysis, supervisory control, remote operation, reduces man power, helps in decision making,

and access to risky areas and multiple controls from single point.

M.Tech in Power and Energy System, EEED, BEC, Bagalkot. 1

SCADA IN KPTCL

2. SCADA technology

The ability to perform operations at an unattended location from an attended station or operating

center and to have a definite indication that the operations have been successfully carried out can

provide significant cost saving in the operation of a system. This is exactly what is achieved

through the SCADA system. A formal definition of SCADA system, as recommended by IEEE,

is “A collection of equipment that will provide an operator at a remote location with sufficient

information to determine the status of particular equipment or a process and cause actions to take

place regarding that equipment or process without being physically present”.

2. 1. Common system components:

A SCADA System usually consists of the following subsystems [2]:

i. A Human Machine Interface (HMI) is the apparatus which presents process data to a

human operator, and through this, the human operator monitors and controls the

process.

ii. A supervisory (computer) system, gathering (acquiring) data on the process and

sending commands (control) to the process.

iii. Remote Terminal Units (RTUs) connecting to sensors in the process, converting

sensor signals to digital data and sending digital data to the supervisory system.

iv. Programmable Logic Controllers (PLCs) used as field devices because they are more

economical, versatile, flexible, and configurable than special purpose RTUs.

v. Communication infrastructure connecting the supervisory system to the RTUs.

2. 2. Typical SCADA system:

A typical SCADA system as shown in figure 1, is comprised of both software and

hardware components [3].

i. SCADA software, typically running on a plant-based computer, acts as a human-

machine-interface (HMI) to the control system. The SCADA software reads data

from the controller module, displays the data in a timely manner and optionally logs

the data to a local hard drive. SCADA software can also be configured to generate

and log alarms based on user-defined alarm conditions as well as send command

messages to the CPU module.


SCADA IN KPTCL

ii. SCADA hardware includes a central processing unit (CPU or controller module) that

receives data from field sensors, determines control actions based on user-

programmed logic, and then sends control commands to field devices.

Fig 1: A Typical SCADA System [3]

2. 3. SCADA for Power Transmission:

Present day power systems have large interconnected networks. The success of the recently

evolving electricity market structure will heavily depend on modern information systems and

online decision tools. Maintaining system security, reliability, quality, stability and ensuring

economic operation are the major operating concerns. Online monitoring, operation and control

of the modern day power systems have become impossible without computer aided monitoring

& dispatching systems. The basic requirement to fulfill these needs is SCADA.

SCADA provides open architecture rather than a vendor controlled proprietary environment. It

interfaces hardware and software, and it includes functionality such as trending, alarm handling,


Computer

Field Sensors

Field Devices

Power

Supply

Controller Module (CPU)

AIN

Module

DIN

Module

AOUT

Module

DOUT

Module

SCADA HMI Software on PC

Control Hardware

Communication Protocol

SCADA IN KPTCL

logging archiving, report generation, and facilitation of automation. Thus SCADA has been used

has powerful tool for power system automation, that refers to automatic switching, regulating,

controlling, logging, protection etc. of electric power flow without human intervention.

2. 4. SCADA Manufactures:

i. Modicon (Telemecanique) Visual look

ii. Allen Bradly : RS View

iii. Siemens: win cc

iv. Gefanc:

v. KPIT : ASTRA

vi. Intelution : Aspic

vii. Wonderware : Intouch

2. 5. SCADA Benefits:

i. SCADA increases reliability.

ii. It helps in forecasting accurate demand supply management.

iii. It reduces maintenance cost and helps in monitoring of process at remote place.

iv. It reduces human influence and errors.

v. It assists operator for faster decision making.

vi. It helps in automated meter reading and easy fault diagnosis.


SCADA IN KPTCL

3. Brief description of SCADA Project in KPTCL

Prior to implementation of Integrated Extended SCADA (IES) project KPTCL had total of 63

RTUs covering 220 kV, 400 kV and generating stations, only main control systems and 21 RTUs

were acquired. KPTCL set up its own VSAT network to provide the communication back bone

during 1998, the uptime of VSAT network since then is greater than 99.95% [4].

Integrated Extended SCADA (IES) project was implemented to provide reliable, uninterrupted,

quality power to the consumers and provide secure operation and control of the Power System in

the country leading to ‘GRID DISCIPLINE’. For speedy and efficient decision-making and for

running the power system at maximum economy IES project was implemented.

3.1. Objective of IES Project:

i. A common integrated solution to cater to the network extending to the entire state of

Karnataka – covering 854 Stations of Transmission, Generation and Distribution

companies in the I phase.

ii. Integrated Solution for Energy Auditing, Energy Billing and Availability Based Tariff

to meet regulator’s requirement.

iii. Integration of all Sub-station and Generating Station Automation systems.

iv. Data to all ESCOMs for scheduling and monitoring.

v. Facilitate Integration to other “down the line” Distribution Systems of ESCOM.

3.2. Features of IES Project:

i. SCADA to cover receiving stations ranging from 33kV to 400kV.

ii. SCADA to cover Major Generating stations and IPPs.

iii. Data from all feeders from 11 kV to 400 kV.

iv. Area Load Despatch Centre for Six Transmission Zones.

v. Distribution Control Centre for five ESCOMs.

vi. Upgradation of State Load Despatch Centre.

vii. EB/EA/ABT system to perform Energy Billing, Energy Audit and Availability Based

Tariff functions.

viii. Sub-system to perform Open Access operations.

ix. Real time Energy Data Acquisition from all Interface points.


SCADA IN KPTCL

x. Energy Management System and Distribution Management System.

xi. Privately owned VSAT Hub and network with leased bandwidth from INSAT 3A

xii. Disaster Recovery Hub.

3.3. Project information:

i. Project conceived in the year 2002.

ii. Draft specifications prepared in-house from 2002 to 2005.

iii. Specifications vetted by an Expert Committee including members from IISc, CPRI

and experts from the field.

iv. Tenders floated in the year 2006.

v. Project awarded to M/S ABB in December 2006.

vi. Project period : 24 months

vii. Project cost : Rs.186 crores

viii. BESCOM share : Rs.11.2 crores

3.4. IES Components:

i. SCADA Remote Terminal Unit (RTU) ABB Model 560

ii. HP make Servers for SCADA, Data EMS and DMS

iii. HP Work stations for Engineering and Operation

iv. HP make Server for Dispatcher Training Simulator

v. Multi Frequency Time Division Multiple Access (MFTDMA) communication Hub

for VSAT operation of Gilat Israel

vi. Network Manager SCADA and EMS software of ABB Sweden

vii. Oracle 11i for database

viii. Windows XP and MS office 2003 for Work stations

ix. IEC 104 protocol for RTU- Control centre communication

x. Meter Interface card of ABB for Energy meter integration.


SCADA IN KPTCL

xi. Cisco routers for communication interfaces

xii. Bandwidth from INSAT 3A

xiii. OFC solution from BSNL.

3.5. KPTCL SCADA System Architecture:

Figure 2 shows SCADA system architecture at KPTCL. It consists of 16 control centers, which

includes the Main Control Centers (MCC), a Disaster Recovery Centre (DRMCC), Area Load

Despatch Centers (ALDC) for the Transmission Zones and Distribution Control Centers (DCC)

for the ESCOMs.

Fig 2: SCADA System Architecture at KPTCL [4].


SCADA IN KPTCL

List of control centers:

i. Main Load Despatch center (LDC) – 1 No.

ii. Master Control Centers (MCC) – 2 No. i.e., MCC 1 and MCC 2.

iii. Disaster Recovery Master Control Center – 2 No. i.e., DRMCC 1 and DRMCC 2.

iv. Area Load Despatch Centers (ALDC)for the Transmission Zones – 6 No. they are

a. Bangalore Transmission Zone (BNG TRZ).

b. Tumkur Transmission Zone (TMK TRZ).

c. Mysore Transmission Zone (MYS TRZ).

d. Hassan Transmission Zone (HSN TRZ).

e. Bagalkot Transmission Zone (BGK TRZ).

f. Gulbarga Transmission Zone (GLB TRZ).

v. Distribution Control Centers (DCCs) for the ESCOMs – 5 No. they are

a. Bangalore Electricity Company (BESCOM).

b. Mysore Electricity Company (MESCOM).

c. Hubli Electricity Company (HESCOM).

d. Gulbarga Electricity Company (GESCOM).

e. Central Electricity Company (CESCOM).

All the Transmission RTUs communicate to MCC-1 & Distribution RTUs communicate to

MCC-2. The total system is configured with 72 servers and 115 operator workstations.

Communication is on a owned VSAT HUB and Leased Lines for Inter control Centre

Communication [4].


SCADA IN KPTCL

4. Study of SCADA Implemented Substations at Bijapur

According to features of Integrated Extended SCADA project, KPTCL covers all receiving

substation ranging from 33 kV to 400 kV. 110/11kV Bijapur receiving station at City was one of

old station to acquire data, monitor and to control remotely SCADA was implemented at this

station under IES project I phase. 220/110/11kV substation Bijapur near Shivgiri is newest

station which was fully automated with SCADA for remote as well as local control under IES

project. Implementation, working, equipment used at both station are different, hence detailed

study of both stations is described in this section.

4.1. CASE I – 110 kV City Sub station

Location

State : Karnataka

City : Bijapur

Area : Near RTO, Ibrhampur

4.1.1. Over view of substation

110 kV substation is situated at Ibrhampur near RTO office Bijapur. It receives power supply from 220

kV substation Bijapur (double lines) and distribute power to local Bijapur areas such as JalNagar, Jumma

masjid etc (feeders).

4.1.2. SCADA Implementation:

Under Integrated Extended SCADA (IES) Project, adaptation works were basically carried out

on the oldest substation as old as 50 years. Adaptation works for 600 sub station was carried out

and completed in a record time of one year. During this 110 kV City substation Bijapur was

undergone, as it is old substation there was need to acquire data from existing equipment.

Renewing all equipment or replacing old equipment by new equipment will increase cost, it is

not economical also. Thus KPTCL took step to automate existing substation by installing

RTU560A SCADA for automation and send all information to Master Control Center (MCC).

Figure 3 gives general block diagram of implementation of SCADA at all old substation in that

110/11kV substation Bijapur was one of substation.


SCADA IN KPTCL

Fig 3: General Block diagram of Implementation SCADA

According to abbreviation of SCADA, Supervision, Control And Data acquisition are the main

tasks to be carried out at every substation. Supervision - of the incoming line, Control and Relay

Panels (C&R panel), Control - Switch gear and data acquisition - such as Voltage (phase),

current (phase), active and reactive power, frequency etc. Table 1 gives information about

parameters, input and output, relation of these with SCADA at 110/11 kV substations.

Table 1: SCADA, I/O and parameters used at 110/11 kV substation.

SCADA Supervision Control Data Acquisition

Input/Output Digital input Digital output Analog input

Observation • Status indication

• Control & relay panel

• Switch Gears

• CT & PT

• Measured

value such as

voltage current

etc.

Supervision, Control and Data Acquisition at 110 kV City station Bijapur is done by installing

ABB’s RTU 560A which consists of all facilities that required for automation.

About Remote Terminal unit (RTU)

The RTU connects to physical equipment. Typically, an RTU converts the electrical

signals from the equipment to digital values such as the open/closed status from a switch

or a value, or measurements such as pressure, flow, voltage or current. By converting and

sending these electrical signals out to equipment the RTU can control equipment.


Existing

Substation

110/11 kV

SCADA

RTU 560A

Mater Control

Center (MCC)

SCADA IN KPTCL

4.1.3. SCADA Equipments to Substation:

At 110/11kV city substation Bijpaur, consists of the following SCADA equipments. They

are:

i. RTU 560A along with IF panel.

ii. VSAT

• Antenna,

• IDU,

• 8 port switch ,

• telephone

iii. 2 kVA UPS (Power One make) along with

• 8 No of 100Ah, 12V cells

• Battery stand

• ACDB

I. RTU 560A :

Transmission and distribution networks are frequently being expanded, often resulting in

more complex networks. The task of monitoring and controlling the energy transportation

in order to achieve an economical operation. ABB’s solution for transmission and

distribution application requirement is Remote Terminal Unit system RTU560. Within

the RTU560 family the communication unit and the I/O board family is a hardware

system based on standard European format cards. To meet the requirements for typical

medium stations with only some communication links on one side and large or modern

stations with a higher number of IEDs on the other side, the RTU560, based on European

format cards, is available in two versions [5]:

RTU 560A for configurations with higher demands on communications links. The

parallel wired process interface is still part of the configuration.

RTU 560C for typical stations with a parallel wired process interface and some

communication links only.


SCADA IN KPTCL

Fig 4: ABB RTU560A Panel at 110/11 kV substation.

The SCADA RTU560A as sown in figure 4 is small ruggedized computer, which provides

intelligence in the field. It allows the central SCADA master to communicate with the field

instruments. It is stand alone data acquisition and control unit. Its function is to control process

equipment at the remote site such as to open or close the circuit breakers. It acquires data from

the equipment and transfers the data back to the central SCADA system.

Features of RTU 560A:

• 4 serial communication interfaces for host communication

• 32 MB Flash Memory


SCADA IN KPTCL

• 8 MB RAM

• Web Server

• PC104 module with CPU 486/66MHz

• PLC capable

Components of RTU 560A:

Fig 5: Components of RTU 560A.

Figure 5 shows components of RTU 560A, it consists of Basic rack (top rack) with CPU and

communication ports, Extension rack 1 (2nd rack) with Digital Input card (DI) Analog Input card

(AI) and Analog Output card (AO). Digital Output card (DO) at Extension rack 2 (3 rd rack) and

each rack is supported by separate power supply cards. For load alarm annunciation, there is rack

called SCADA annunciation panel. Table 2 gives details of components and their function.


SCADA IN KPTCL

Table 2 : Details of RTU 560A component.

Sl No. Components Quantity Function

1 Multifunction Transducer (MFT) 30 30 no. of bays data can be

collected.

2 Digital Input Card (DI card) 8 Each card supports 16 digital

inputs.

3 Digital output Card (DO card) 5 Each card supports 16 digital

outputs.

4 Analog Input Card (AI card) 3 Each card supports 8 inputs.

(DC Voltage, Tap position…)

5 Analog Output Card (AO card) 1 2 linear control

6 Digital Output Relays 80 40 breakers can be controlled.

(One relay for trip, one for close )

7 Meter Interface card 1 For acquiring ABT Energy meters

located at IF points

8 Communication Card 2 Each having 4 ports for

communication.

9 AC-DC Converter 2 For providing DC power supply

to rack (48 V).

10 SCADA Control Annunciator 1 Provides alarm for operator.

11 Optocoupler 3 To isolate voltages (110V dc &

48V).


SCADA IN KPTCL

Description of RTU 560A components:

1. Multifunction Transducer (MFT): A Transducer is a device, usually electrical,

electronic, or electro-mechanical, that converts one type of energy to another for the purpose of

measurement or information transfer. At substation multifunction transducers are used change an

electrical quantity such as voltage, current, power or frequency into a proportional dc output.

Fig 6: Multifunction transducer.

Multi-function transducers are used for measuring wide range of analog values in a 3-phase 4-

wire and 3-phase 3-wire balanced and unbalanced systems. Figure 6 shows MFT used at 110/11

kV substation, it can measure 96 electrical parameters from single transducer. MFT with latest

technology provides combination of high accuracy and comprehensive functionality. They have

compact structure and MODBUS RTU support for remote interrogation of energy and

instantaneous parameters. Table 3 shows technical specifications.

Table 3 : Technical specification of MFT

Sl No. Parameter Values

1 Connection type 3 phase 4 wire

2 Communication protocol MODBUS

3 Output current 4-20mA

4 Parameters measured Voltage, current , frequency, active power,

reactive power, energy import and export.


http://en.wikipedia.org/wiki/Energy

http://en.wikipedia.org/wiki/Electro-mechanical

http://en.wikipedia.org/wiki/Electronics

http://en.wikipedia.org/wiki/Electricity

SCADA IN KPTCL

2. Digital Input Card (DI card): Status indication from control & relay panel are given to

DI card. At substation binary input board 23BE23 is used for the isolated input of up to 16 binary

process signals. Scanning and processing of the inputs are executed with the high time resolution

of 1 ms. Allocation of an input to a processing function can be done according to the rules of

configuration. Figure 7 shows 23BE23 binary input board.

Fig 7: Binary input board 23BE23.

The board has sixteen light emitting diodes to indicate the signal-state. The LEDs are organized

in two columns on the front plate. The LED follows directly the input. The 23BE23 board has a

buffer which allows the temporary storage of 50 time-stamped event messages in chronological

order designated for transmission to the communication unit. Table 4 shows technical

specification of 23BE23 DI card.

Table 4 : Technical specification of 23BE23 DI card


1 Power supply 5V, 140mA

2 Inputs 16, in 2 groups of 8 withcommon return per group

3 Input voltage 24, 48, 60 V DClog. 0: ≤ + 9 Vlog. 1: ≥ +18 V

4 Input current Typically. 2 mAfor 24 to 60 V DC


SCADA IN KPTCL

3. Digital output Card (DO card): Connection from switch gear is connected to DO card.

At substation binary output board 23BA20 is used. The binary output is made via relay contacts.

Resistive loads of up to 60 W can be switched with output voltages between 24 and 60 V DC.

The process relays to be switched have to be equipped with zero voltage diodes. Figure 8 shows

23BA20 DO card. Operating status and faults are displayed by light emitting diodes on the front

panel of the 23BA20, ST: Common malfunction information of the board, PST: Command

output fault condition display when the monitoring system responds CO: Command output

display during output time. Table 5 gives technical specification of the binary output 23BA20

card.

Fig 8: Binary output board 23BA20.

Table 5 : Technical specification of 23BA20 DO card.


1 Power supply 5 V / 120 mA, 24 V / ±10 mA per relay

2 Outputs 16 relay contacts single pole, 2 groups of

8 with common return.

3 Relay max. switching voltage 60 V DC

4 Continuous current ± 4 A


SCADA IN KPTCL

4. Analog Input Card (AI card): At substation analog input card 23AE23 is interfaced to

CT and PT at field for measurement. The 23AE23 board records up to eight analog measured

values. The 23AE23 board allows it to connect all typical measured value ranges. Figure 9 shows

analog input 23AE23 card. The analog input board 23AE23 can carry out the following

processing functions on the measured values : Zero point monitoring, Switch-over recognition,

Smoothing and Threshold value monitoring on absolute value or with accumulation and periodic

background transmission. Table 6 shows technical specification of 23AE23 card.

Fig 9: Analog input board 23AE23.

Table 6 : Technical specification of 23AE23 AI card.


1 Power supply 5V / 190 mA.

2 Inputs 8 differential inputs

3 Measuring ranges ± 2 mA, ± 5 mA, ± 10 mA, ± 20 mA

± 40 mA, ± 2 V DC / 0 … 20 V DC


SCADA IN KPTCL

5. Analog Output Card (AO card): Via the analog output board 23AA21, analog control

outputs for sequential or closed loop control, display instruments, measurand recorders etc. can

be connected to the RTU560. Each output has a digital to analog converter (DAC) which

converts the digital value present in the output memory into an analog signal. A received output

value is stored until a new value is received. At substation they are used for measurement of On

Load Tap Changer (OLTC), temperature etc. Figure 10 shows 23AA21 analog output card.

Table 7 gives technical specification of 23AA21 analog output card.

Fig 10: Analog output board 23AA21.

Table7: Technical specification of 23AA21 AO card.


1 Power supply 5 V / 650 mA

2 Outputs 2

3 Output current: ± 2,5 mA, ± 5 mA, ± 10 mA, ± 20 mA

(4...20 mA)

6. Digital Output Relays: At substation there are 80 output relays which can control 40

circuit breakers. One relay for trip and one relay for close are used. These signals are given to

field circuit breakers and tap changer from remote place by operator.


SCADA IN KPTCL

7. Meter Interface card (MIC): Energy billing for Availability Based Tariff was one of

the most important feature for substation automation. There are energy meters at substation of

different manufacturers, all over Karnataka 5000 meters are present, to collect data from these

meters SCADA uses 560 MIC. RTU 560A consists of this card with RS 485 and Ethernet port.

Banks at substation consists of Electronic Trivector Meter (ETV), MIC gets energy consumption

information from this meter. RS 485 communicates MIC and ETV meter. MIC is just a flash

memory; it transfers data from ETV to Energy Billing (EB) server once polled.

8. Communication Card (CMU): The RTU560 CMU boards are based on the PC 104

concept. A PC 104 main board contains the kernel of a personal computer (PC) and has become

standard recently. It allows the easy integration of standard PC-based software as well as easy

adaptation to specific hardware extensions. Each CPU communication board has an additional

serial interface for MMI to a PC. The MMI is used for diagnostics, up and download of

configuration files, etc. Figure 11 shows communication unit 560CMU 04. Table 8 gives

technical specification of 560CMU 04.

Fig 11: Communication Unit 560CMU 04.

Table 8: Technical specification of 560CMU 04.


1 Ethernet 100Mbit/s,10/100 BaseT

2 Serial Line Interfaces 4 x RS 232C or RS 485,1 x MMI RS 232C


SCADA IN KPTCL

9. AC-DC Converter: All racks of RTU560A consists of power supply unit 560PSU01

which require DC supply of 48V, thus AC-DC converter is used. This unit supplies required DC

power to all racks of RTU panel.

10. SCADA Control Annunciator: This is provided to show indication that control of

device is operated through SCADA. It consists of Light Emitting Diodes (LED) which is

provided for either OPEN or CLOSE of circuit breaker. Figure 12 shows SCADA Control

Annunciator. Acknowledgement for open or close is done through SCADA reset button.

Fig 12: SCADA Control Annunciator.

11. Optocoupler: Control and Relay panel is provided with 110V DC supply but RTU 560A

operates at 48V signals & data cannot be directly transferred from C&R panel to RTU because of

different voltage levels. Hence Optocoupler is used to isolate the difference in voltage. Figure 13

shows Optocoupler.

Fig 13: Optocoupler.


SCADA IN KPTCL

II. VSAT:

VSAT technology represents a cost effective solution for users seeking an independent

communications network connecting a large number of geographically dispersed sites. This is

the first system of its type and scope to be installed anywhere in the world, and helps KPTCL

monitor, control and deliver electricity to roughly 14.6 million customers, across a coverage area

of 192,000 sq. km.

The entire data acquisition is done over VSAT from the RTUs to the main control centers on IEC

104 protocol, a unique communication media deployed in the country by an electricity utility.

Components of VSAT are antenna, Indoor unit (IDU) and Outdoor Unit (ODU). To avoid

communication problem separate SCADA phones (VOIP) are provided at each substation. 8 port

switch is provided for separate connection for MIC, IDU, Voice Over Internet Protocol (VOIP),

CMU etc.

III. UPS:

2 kVA UPS with 8 No of 100Ah, 12V cells is provided for RTU 560A for back power supply.

4.1.4. SCADA connections:

Connection diagram for all SCADA equipment and C&R panel at 110/11 kV substation city

Bijapur is described in this section. General block diagram is shown in figure 14, usually from

existing C&R panel connections are brought to RTU’s card through interface panel. Interface

panel consists of MFTs and Terminal Blocks (TB) for easier connection; some new TBs are also

placed in C&R panel.

Fig 14: Block diagram for connection of 110/11kV substation.


Control and Relay panel.

Interface Panel with MFTs and TB.

RTU Panel with DI, DO, AI, AO cards.

MIC, PSU and CMU Modules.

SCADA IN KPTCL

Connection diagram for Digital input interfacing:

For supervision of status of circuit breakers, isolator, faults at remote place, C&R indicator bulbs

are interfaced to RTU DI Card as shown in figure 15.

Fig 15: Connection for DI card.

Status indicators at C&R panel are connected in series to DI card of RTU through Optocoupler

and passed through TB of interface panel. TB are used for easier connection of wiring,

Optocoupler is used to isolate difference in voltages of C&R panel (110V Dc) and RTU (48V

Dc).A common implementation involves a LED and a phototransistor as shown in circuit

diagram figure16 , separated so that light may travel across a barrier but electrical current may

not. When an electrical signal is applied to the input of the Optocoupler, its LED lights, its light

sensor then activates, and a corresponding electrical signal is generated at the output. Thus status

indications from substation are brought to master control centre through DI card.


Control and Relay Panel

Status indication

Optocoupler

Interface Panel

TB

RTU Panel

23BE23 DI Card

SCADA IN KPTCL

Fig 16: Circuit diagram of Optocoupler.

Connection diagram for Digital output interfacing:

To control circuit breaker remotely, TNC (Trip Neutral Close) switch at C&R panel is interfaced

to RTU DO card as shown in figure 17.

Fig 17: Connection for DO card.


Control and Relay Panel

TNC Switch

ON OFF

Optocoupler

Interface Panel

TB

RTU Panel

23BA20 DO Card

SCADA IN KPTCL

Circuit breaker is opened or closed remotely by SCADA Digital Output command via DO relay.

Also tap changer of transformer is operated from RTU DO relay. Circuit diagram for digital

output interfacing of CB and transformer tap change is shown in figure 18.

Fig 18: Connection of TNC & SCADA command.

Connection diagram for Analog input interfacing:

Analog input card of RTU is interfaced to CT and PT of filed for measurement of parameters.

Wiring diagram for CT & PT of field to MFT is shown in figure 19. Connection diagram for

RTU AI card is shown in figure 20.

Fig 19: Wiring diagram for CT & PT to MFT.


SCADA IN KPTCL

CT and PT from field

Fig 20: Connection for AI card.

Electrical quantity such as voltage, current, power or frequency measured values are transferred

into a proportional dc output by MFT. MFT provides desired signal of 4-20 mA to the AI card.

4.1.5. Operation:

Operations carried out 110/11kV substation are

• Real time data acquisition from RTUs.

• Status monitoring and alarming.

• Sequence of event recording.

• Information storage.

• Data retrieval for ABT functions.

• Real time data acquisition from RTUs: Load Despatch Center (LDC) requires data

with respect to available generation and load to be attended. As such real time data is

required from all Generating stations; real time data is required from receiving stations;

real time data is required from Interface points from where power is delivered to


C&R panel

SCADA

TB

Interface Panel

MFT

RTU Panel

23AE23 AI Card

SCADA IN KPTCL

Distribution companies or Consumers. RTU560A provides real time data such as Feeder

ON OFF indication, Circuit Breaker status, tap change of transformer, etc. to LDC.

Operator at LDC can observe single line diagram of substation shown in figure 21.

Fig 21: Monitoring screen of 110/11kV substation at control center.

• Status monitoring and alarming: If operator at LDC operates any of circuit breaker

remotely, to indicate this information for local operator at substation SCADA Control

Annunciator is provided in RTU 560A, which alarms operator. At present only few

substation at Bangalore is operated remotely.

• Sequence of event recording: RTU 560A also provides facility of recording events

about fault occurred at substation.

• Information storage & Data retrieval for ABT functions: RTU 560A collects analog

data like MW, MVAr, kWh import/export, frequency, voltage from metering core of CT,

PT through MFTs and digital indications like CB open, close, auto trip, Isolator open.


SCADA IN KPTCL

Energy billing is one of the KPTCL SCADA applications, to achieve this customized Meter

Interface card (MIC) is provided at the RTU to integrate the Interface (IF) points Special

Energy meters. Connection diagram for IF point at substation is shown in figure 21.The

Energy Billing system downloads the data from the Energy meter at predefined time. Data

acquired to carry out Energy Billing and UI (Unscheduled Interrupt charge) billing for

ESCOMs and for Intra State ABT (Availability Based Tariff) billing.

Fig 22: Connection of IF point at substation.

Energy meters at substation are conventional meter and manufactured by different manufactures.

There was no uniformity and accuracy was less in meter, no communication protocol to take data

from meter. Thus KPTCL under gone to some Special Energy meters with 3- ph 4 wire and had a

communication port of RS485.

Banks of substation consists of Electronic Trivector Meter (ETV) manufactured by either L&T

or SEMs. If a bank consists two or more meter then they are looped and connected to MIC of

RTU through the RS485. MIC is firmware with buffer once polled it takes data from meter and

transfers it to Energy Billing (EB) server. RTU 560A collects analog data like MW, MVAr, kWh

import/export, frequency, voltage from metering core of CT, PT through MFTs and digital

indications like CB open, close, auto trip, Isolator open. These data can be remotely accessed by


SCADA IN KPTCL

operator at ABT wing for Energy Billing and also same data can be downloaded to laptop at

substation.

Fig 23: IF meter reading setup for energy billing.

Figure 22 shows IF meter reading setup for Energy Billing at ABT through EB server. Every

energy meter at substation is given a unique identification No. for accessing information at

remote place. Operator at ABT wing has ABT drive software with MIC configuration through

which he can ping MIC to get data. Phase 1 MIC is using Kalki software and phase 2 MIC is

using Cushy link software. L&T meter can store data for 30 days and SEMs meter for 20 days.

Data transfer is done on 96 block base for one day for every 15 min. For example IP address for

polling a meter is 10.6.1.12, it defines as

10 : Common No.

6 : Zonal No. for each district

1 : RTU No. at substation

12 : Energy meter No. (L&T -12 and SEMs-13)

Thus data is received from substation at ABT wing and used for Energy Billing.


SCADA IN KPTCL

4.2. CASE II – 220kV Shivgiri Sub station

Location

State : Karnataka

City : Bijapur

Area : Shivgiri

4.1.1. Over view of substation

220 kV sub station is situated at Shivgiri, Ukkali road Bijapur. It was commissioned on

19/12/2008 and load was taken on 14/03/2009. It receives power supply from 220 kV substations

Basavan Bagewadi Bijapur (double lines) and distributes power to local Bijapur, Indi. Feeder

from 220 substations to Ainapur and Ukumnal.

Details of Line:

1. 220kV BGD-BJP-1 I/C line.

2. 220kV BGD-BJP-2 I/C line.

3. 220kV BJP-INDI-1 O/G line.

4. 220kV BJP-INDI-2 O/G line.

5. 110kV BJP-KIADB-1 O/G line.

6. 110kV BJP-KIADB-2 O/G line.

7. 110kV BJP-City O/G line.

8. 11kV Ainapur.

9. 11kV Ukumnal.

10. STN AUX.

Equipment Details:

Table 9: Equipment details of 220kV substation.

Sl No. Equipment Make Quantity

1 220kV Circuit Breaker ABB 07

2 Power transformer Areva 2*100MVA

3 Power transformer SPEC 1*10MVA

4 110kV Circuit Breaker ABB 09

5 11kV switch gear MEI 1+5


SCADA IN KPTCL

4.1.2. SCADA Implementation:

200/110/11kV Shivgiri substation Bijapur is newly installed substation. Under IES project,

automation of new substation is done through Substation Automation System (SAS) using IEC

61850. The functions performed by Substation Automation (SA) system are in, general, switch

control, data monitoring, protection etc. In IEC-61850, these functions are broken into low-level

functions called sub-functions. Each sub-function is performed by the IED installed in the

substation. Each IED can perform one or many sub functions. A set of sub-functions is integrated

together to realize a substation automation function. These communicate with each other through

Local Area Network in the substation. Specific syntax and semantics are defined for

communication between sub-functions. All the possible sub-functions have been standardized in

IEC-61850.Information produced and required by each substation is given in the IEC-61850

standard [1].

The sub functions are assigned at three levels as shown in figure 23: (i) Process level (ii) Bay

level (iii) Station level

Fig 23: Levels defined in IEC 61850.

Process level function: extracts the information from sensors/transducers in the substation and

to send them to upper level device, called bay level device. The other major task of process level

function is to receive the control command from bay level device and execute it at the

appropriate switch level.


SCADA IN KPTCL

Bay level functions: acquire the data from the bay and then mainly act on the primary (power

circuit) equipment of the bay. The different conceptual subparts of a substation are encircled by

line in figure 24.

Fig 24: Conceptual Substation Bays.

Station level functions: are of two types.

(i) Process related functions act on the data from multiple bays or substation level database.

These functions are used to submit the control commands for the primary equipment (Circuit

breakers) and collect the substation data like voltage, current, power factor etc. from the bay

level devices. Each bay includes one primary equipment such as transformers, feeders etc.

(ii) Interface related functions enable interactive interface of the substation automation system to

the local station operator HMI (Human Machine Interface), to a remote control centre for

monitoring and maintenance.


SCADA IN KPTCL

There are basically two types of equipment in a substation:– (i) primary equipments and (ii)

secondary equipments. Primary equipments include transformer, switchgear etc. Secondary

equipments include protection, control and communication equipments. Further, secondary

equipments are categorized into three levels in IEC-61850 standards. These are station level, bay

level, and process level equipments. A conceptual substation automation system based on the

IEC 61850 standard is evolved and depicted in figure 25.

Fig 25: Conceptual Substation Automation Topology.

With this conceptual view at 220kV substation Bijapur there are 8 bays divided. Control and

monitoring operation is carried out both remotely and locally. At substation 4 IEDs are used for

collecting information and OFC is used for local communication, for remote communication

Ethernet and VSAT is used. SAS consists of Bay Control & Protection Panel and Protection

Panel, they are manufactured by ABB. Control & Relay panels and Protection panel are inbuilt

in ABB panel.

4.1.3. SCADA Equipments to Substation:

220/110/11kV substation control room is provided with Bay Control & Protection panel and

Protection panel by ABB. All the ABB panels are equipped with 4 IEDs used for protection and

control. ABB’s IED 670 series provides reliable, efficient and flexible protection, monitoring

and control for all applications in sub-transmission and transmission systems. IED provides a


SCADA IN KPTCL

common powerful hardware platform and an extensive hardware-independent, modular function

library. Setting, commissioning and maintenance procedures of all IED are fast and simple. All

are similar hence user can learn about one to know them all. These can communicate easily with

IEC61850.

List of Intelligent Electronic Device (IED) 670:

1. RET670-Transformer Protection IED.

2. REC670-Bay Control IED.

3. REL670-Line Distance Protection IED.

4. REB670-Busbar Differential Protection IED.

RET670-Transformer Protection IED: It is used for reliable protection & control of all

types of power transformers and reactors. Also it provides protection solution for any type of

transformer & shunt reactor application. It gives freedom to select functionality according to

our needs, basic functionality is included and pre configured. A single RET670 can integrate

complete protection & control functionality for a transformer & a connected transmission

line. The distance protection function can also be used as back up protection for faults with in

transformer & in connected lines. In all, RET670 increases reliability and profitability of

entire power system. Figure 26 shows RET670 IED.

Fig 26: RET670-Tansformer protection IED.

It is designed to operate correctly over a wide frequency range in order to accommodate

power system frequency variations during disturbances. RET670 features also several

function for local and remote apparatus control on all sides of transformer. It provides a large

HMI for local control and instantly accessing important data, such as settings, events and


SCADA IN KPTCL

disturbance information. 30 apparatuses can be controlled and visualized. Large HMI

provides overview of quick status of substation with position indications and service values.

REC670-Bay Control IED: It provides optimized control and reliable operation of switch

yard. It provides pre configured control solution for any type of switch gear and different

switch gear configuration. REC670 enables the manual control of a tap-changer from a

Substation Automation system. It also integrates advanced voltage control for transformers in

a substation in a single IED. This eliminates the need for dedicated voltage control devices in

cases where the transformer protection is not equipped with voltage control.

The REC670 IEDs feature a large HMI for local control and instant access to important data,

such as settings, events and disturbance information. The control is based on the select before

operate principle to ensure secure operation and to avoid human mistakes. Control screen can

be selected as default screen. Control commands can be directly executed and important

measurements can be read. All measurements are available in IED can be shown on HMI.

Graphical display can be configured as it is at substation. Figure 27 shows REC670 IED.

Fig 27: REC670 -Bay control IED.

REC670 is able to handle a large number of analog signals from CTs and VTs. The

outstanding I/O capability enables control of several bays with complete measurement with

only one IED. One REC670 IED is capable of handling control of all apparatuses in one

entire diameter in 1 ½ breaker arrangement including breaker failure protection for all

breakers.

REL670-Line Distance Protection IED: It provides versatile protection, monitoring and

control functionality with maximum flexibility and performance optimized for transmission


SCADA IN KPTCL

overhead lines and cables. The powerful IED provides distance protection for double circuit,

parallel operating and series compensated lines. REL670 IEDs are able to protect and control

several objects, for instance a combination of a line and a transformer with a single IED. As a

result, this IED increases both the reliability and profitability of entire power system.

REL670 provides both customized and pre-configured protection solutions. The pre-

configured IEDs are equipped with complete functionality adapted for four different

configuration alternatives: single pole breaker or multi-breaker arrangements with single or

three phase tripping. Figure 28 shows REL670 IED.

Fig 28: REL670-Line distance protection IED.

REL670 provides protection of power lines with high sensitivity and low requirement on

remote end communication. Measurements and setting of all five zones with six setting

groups are made completely independent, which ensures high reliability for all types of lines.

The distance and earth-fault protection functions can communicate with remote end in any

communication scheme. It offers full control and interlocking functionality required for

control of apparatuses in a substation. The integrated HMI allows secure and quick local

control for stand-alone applications and provides back-up control for substation automation

systems. REL670 provides efficient substation automation solutions in terms of performance,

redundancy and cost for any high voltage application.

REB670-Busbar Differential Protection IED: It is designed for the protection and

monitoring of bus bars. REB670 protects single and double bus bars with or without transfer

bus, double circuit breaker or one-and-half circuit breaker arrangements. It provides

selective, reliable and fast fault clearance for all types of internal phase-to-phase and phase-

to-earth faults in solidly earthed or low-impedance earthed power systems. At the same time,


SCADA IN KPTCL

it maintains complete stability for external faults, even when heavy CT saturation occurs. It

can also handle all internal multi-phase faults in isolated or high-impedance earthed power

systems. Figure 29 shows REB670 IED.

Fig 29: REB670-Bus bar differential protection IED.

4.1.4. SCADA Connections:

At 220/110/11kV substation, Substation Automation System (SAS) consists of 27 panels for

protection and bay control. Layout of panels at control room is shown in figure 30.

• B&P - Bay Control & Protection Panel

• P - Protection Panel

• BBA - Bus Bar Protection Panel

• INDI 1 – Indi line 1

• INDI 2 – Indi line 2

• TRF 1 HV – Transformer 1 HV side

• TRF 1 LV – Transformer 1 LV side

• TRF 2 HV – Transformer 2 HV side

• TRF 2 LV – Transformer 2 LV side

• BGD 1 – Basavan Bagewadi line 1

• BGD 2 – Basavan Bagewadi line 2


SCADA IN KPTCL

For SAS

220kV line

INDI 1

P

INDI 1

B&P

INDI 2

P

INDI 2

B&P

Bus Coupler

B&P

TRF 1

HV

B&P

TRF 1 LV

B&P

BGD 2

P

BGD 2

B&P

BGD 1

P

BGD 1

B&P

TRF 2 HV

B&P

TRF 2 LV

B&P

110kV line 11kV feeder

Fig 31: Layout of panels at Control center at 220/110/11kV substation.


SAS SUX

Station Auxiliary

Bay Control Panel

2BBA1

220kV Bus Bar

Protection Panel

2BBA2

220kV Bus Bar

Protection Panel

Feeder

1&2

B&P

Feeder

3&4

B&P

Feeder

5&6

B&P

11kV

Bank

B&P

10 MAV TRF

HV 110/11kV

110kV BGD

B&P

110kV Bus

Coupler

IE 2

B&P

Bijapur

B&P

IE 1

B&P

SCADA IN KPTCL

IES project provides Ruzzegged com (Ethernet) Switch, 3 personal computers – DRPC, SAS1

and SAS2, printer, event list recorder and for communication VSAT, OFC. Connection of ABB

panels is shown in figure 31. There are 8 bays at substation; at each bay have one ruzzegged com

switch which connects all bay information to main SAS through OFC. Information from SAS

can be monitored and controlled locally and also information is sent to Master Control center

(MCC).

Fig 32: Connection of ABB panels at substation.

As shown in figure 31 communication network used is Star-Ring topology. This topology has

potential to provide time delay within allowable range and also offers the better reliability of the

process bus.


SCADA IN KPTCL

4.1.5. Operations:

Local operator at substation control room observes and monitors 220kV, 110kV and 11kV lines.

Single line diagram monitoring screen display of 220/110/11kV, 110kV and 11kV line is shown

in figure 32(a), 32 (b) and 32(c) respectively.

Fig 33(a): Single line diagram display of 220/110/11kV line at control room.

Overview of 220/110/11kV substation Bijapur is monitored by monitored by operator at control

room. Same single line diagram is displayed at remote control center. In single diagram display

of SCADA screen symbols of Lighting Arrestor (LA), Gang or Group Operated switch (GOS)

and Circuit Breaker (CB) are used. Table 9 shows symbols used for SCADA.


SCADA IN KPTCL

Sl No. Equipment Symbols Identity No.

1 Lighting Arrestor

(LA) grounding

89CE

2

Gang or Group

Operated switch

(GOS)

89D

3 Circuit Breaker (CB) 52

Table 10: Symbols used in SCADA Screen.

Fig 33(b): Single line diagram display of 110kV line at control room.


SCADA IN KPTCL

Fig 33(c): Single line diagram display of 11kV line at control room.

At present operator at substation operates 11kV circuit breakers at control room. He note down

the measurement values displayed on monitoring screen as shown on figure 33. Real time values

are noted at every one hour and daily load is generated. Also SAS provides facility of event

recording and alarms for operator.

There is also facility to operate GOS remotely. With the help of IED fault can be recorded. 100

disturbance records can be maintained with time and date. Indication during disturbances is

displayed which helps operator to carry out precaution or solve the problem.


SCADA IN KPTCL

Fig 34(a):220kV measurement values.

Fig 34(b):110kV measurement vaues.


SCADA IN KPTCL

5. Load Despatch Center (LDC)

Load Despatch Center (LDC) is the hub for load despatch and control, it requires acquiring all

data from generation and substation to match generation and load. LDC requires data with

respect to available generation and load to be attended. As such real time data is required from

all Generating stations; real time data is required from receiving stations; real time data is

required from Interface points from where power is delivered to Distribution companies or

Consumers. LDC also has to exercise control over the receiving stations, and consumers and if

necessary the Generators also. As such, Supervisory control is required to shed loads by opening

a breaker, Supervisory control is required switch off or switch on a consumer, Supervisory

control is required to control the generation as and when control is extended.

Scenario of power system without control centers:

There was no Grid Discipline.

Due to indiscipline there was problem of low voltage and low frequency.

There were frequent Grid failures.

Non optimum utilization of available resources.

There was no real time availability of data/ events occurring.

Inefficient Power System Operation & Load Management

Due to no regulation wide gap in Demand - Supply position.

Low voltages at Consumer end.

To overcome all problems India undergone Grid Discipline through SCADA. In this view all

Generation station, receiving station and distribution station were integrated in project. Thus data

from 110kV & 220/110/11kV substation Bijapur are sent to LDC for further operation. LDC’s

architecture, function is briefly explained in this section.


SCADA IN KPTCL

Indian Power System Load Despatch Centers is divided into

At National level

National Load Despatch Centre (NLDC)

At Regional Level

Five Regional grids

Regional Load Despatch Centres (RLDC)

At State Level

State Load Despatch Centre (SLDC)

SLDCs at each state

A typical architecture of an Energy management system is shown in figure 34.

Fig 35: A typical architecture of an Energy management system


SCADA IN KPTCL

As shown in figure 34 data collected from all substations through SAS or RTU is sent to Area

control center (ACC) and then same data is communicated to Regional Control Center

(RCC).National control center will look after the whole grid. There are 5 Regional Load

Despatch Center, they are

Northern Regional Load Despatch Center (NRLDC)

Eastern Regional Load Despatch Center (ERLDC)

Southern Regional Load Despatch Center (SRLDC)

Western Regional Load Despatch Center (WRLDC)

Northern Eastern Regional Load Despatch Center (NERLDC)

Southern region consists of 5 State Load Despatch Centers, they are

Pondicherry

Tamilnadu

Kerala

Karnataka

Andhra

Central generation plants, State generation plants and Independent Plant Producers (IPP) connect

to common Power Grid of India. As objective of LDC is to match generation and load, there is

need to continuously monitor and control.

Karnataka states Load Despatch Center is situated at Bangalore. At SLDC Control center, Grid

connection of southern region is observed. Role of SLDC is to collect information from electrical

companies of Karnataka and send data to SRLDC. Generation and load of state is monitored and

controlled by SLDC. SLDCs send the requisition of load to the SRLDCs, against their

entitlements out of available power from Central Sector Generation and the SRLDCs allocate

total available power to various states in the ratio of their entitlements. According to available

power SLDCs schedule power for state previous day & ESCOMs had to operate according to

schedule. If there is any problem at generation then it informed to SLDCs by revising. SLDCs

control state generators according to load. Data acquired at SLDC is used for Energy auditing,

Energy billing and Availability Based Tariff (ABT).


SCADA IN KPTCL

SRLDC collects data from SLDC and controls Central Generation. NLDC monitors all SRLDC

and communicate with Central electricity Authority (CEA).

5.1. SCADA Application at LDC:

1. Network application overview: The SCADA systems caters to the whole of Karnataka

state which has five Distribution companies and 23 major generating stations and major

IPP’s and Central Generation Share. Figure 35 shows monitoring screen at control center

for Karnataka state.

Fig 36: Monitoring screen for Karnataka state.

At LDC, operator can observe generation, power flow, schedule and actual energy

available etc as depicted in figure 35.


SCADA IN KPTCL

2. Open Access Monitoring: IPP can go for open access if they wish SCADA also

provides information about open access monitoring screen for operator.

3. ABT monitoring Screen: At KPTCL tariff is basically classified into 3 components,

they are; Energy consumption, Maximum demand and Unscheduled Interruption (UI).

UI component is dependent on frequency, when load exceeds generation frequency

decreases depend on decrease in frequency additional charges are penalized. Figure 36

shows ABT Monitoring Screen at control center. UI charges are decided by CEA.

Fig 37: ABT Monitoring Screen


SCADA IN KPTCL

6. Maintenance

Maintenance:

As SCADA is integration of hardware and software, care must be taken that there exist proper

synchronization between them. RTU 560A at 110/11kV substation City Bijapur is digital

equipment no maintenance is required but proper cleaning of panel has to be carried out. Minor

work for adaptability of SCADA at 110/11kV substation were improvement of earthing,

Restoration of control desk (this includes, providing indication lamps, closing coils and TNC

switches) and Wiring of breaker position indication in 11kv.

Improvement of earthing is done by providing one CI pipe electrode as per KPTCL standard CI

earthing 50 x 6 mm MS flat for connection to earth mat 50 x 6 mm GI flat for raisers new RTU is

connected to same earth with other C&R panel. Figure 37 shows connection for improvement of

earthing.

Fig 38: Connection for improvement of earthing.

When earth mat is not provided at substation, earth resistance for SCADA has to note down

after installation work at particular substation. Table 10 gives SCADA earth resistance at

110/11kV substation Atarga during visit with ABB committee on 08/07/2011. UPS for RTU

560A will under go test for battery back up condition.


SCADA IN KPTCL

Table 11: Earth resistance for SCADA

Sl No. Equipment Resistance in Ω/V

1 SCADA CI Pipe 0.28Ω/0.6V

2 VSAT GI pipe 0.29Ω/0.6V

3 RTU Panel 0.23Ω/0.5V

4 C&R panel 0.25Ω/0.4V

5 110kV TRF 0.6Ω/0.9V

6 11kV TRF 1.0Ω/0.9V


SCADA IN KPTCL

Conclusion

Power Systems are large complex systems covering vast areas National / continental grids and

highly nonlinear, high order system. Many process operations need to be coordinated and

Millions of devices requiring harmonious interplay. The Energy flows from various Generating

stations to various Receiving Sub stations via Transmission networks. For maintaining system

security, reliability, quality, stability and ensuring economic operation, on line monitoring,

operation and control of the modern day power systems is required. The basic requirement is of

power system automation is achieved by SCADA.

SCADA helps KPTCL by providing line flows in real time to Generation, Receiving station and

Distribution station. Also provides open access customers and Companies, to satisfy ‘Right to

Information Act’, monitoring open access customer, extending ABT type of operations down to

ESCOM level. Proper control on UI exchanges to ESCOM and Upgradation of SLDC. With help

of SCADA gap between generation and load can be filled. Thus, SCADA is the back bone of

effective Load management and is assuming greater importance in the Power Sector.


SCADA IN KPTCL

References:

1. R. P. Gupta, “Substation Automation Using IEC61850 Standard”, Fifteenth National Power

Systems Conference (NPSC), IIT Bombay, December 2008.

2. “Remote Substation Monitoring And Control through SCADA”, training report, 05-09

October 2009.

3. Martin Chartrand, “Dual Redundant Controller Systems”, Control Microsystems White

Paper, October 2004.

4. Integrated Extended SCADA project KPTCL report (ppt).

5. ABB RTU 560A and ABB IED 670 Manual.


SCADA IN KPTCL

ABBREVATION:

SCADA Supervisory Control And Data Acquisition

RTU Remote Terminal Unit

IED Intelligent Electronic Devices

IEC International Electro technical Commission

SAS Substation Automation System

MCC Master Control Center

HMI Human Machine Interface

LDC Load Despatch Center

ABT Availability Based Tariff

IES Integrated Extended SCADA

EB Energy Billing

EA Energy Auditing


SCADA IN KPTCL

Annexure

RTU Composition at KPTCL

Sl No. Manufacturer Quantity

1 68 k (CMC) 12

2 Micra (Canada) 28

3 GE Harris (USA) 21

4 Micro Scada Locations 02

5 ABB 560 23+1200

Stations covered at IES project KPTCL


SCADA IN KPTCL


industrial trianing[1]

Documents