A Case Study on SCADA Implementation in 220 kV Substation

INTERNATIONAL JOURNAL FOR RESEARCH IN EMERGING SCIENCE AND TECHNOLOGY, VOLUME-2, ISSUE-7, JULY-2015 E-ISSN: 2349-7610

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A Case Study on SCADA Implementation in

220 kV Substation

Vinuta V Koluragi1

M.Tech(Power and Energy Systems)

Assisstant Professor

B.L.D.E.A’s V P Dr P. G. Halakatti College of Engg. & Tech., Bijapur.

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 (Supervisory Control And Data Acquisition). It is a boon to the automation concept of

dynamic technology. 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. Karnataka Power

Transmission Corporation Limited, 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.

Keywords: Real Time Monitoring and Controlling, SCADA, RTU, ABT.

NOMENCLATURE

SCADA : Supervisory Control And Data Acquisition

RTU : Remote Terminal Unit

ABT : Availability Based Tariff

1. INTRODUCTION

Karnataka Power Transmission Corporation Limited is a

registered company under the Companies Act, 1956 was

incorporated on 28-7-1999 and is a company wholly owned by

the Government of Karnataka with an authorized share capital

of Rs. 1000 crores. KPTCL was formed on 01-08-1999 by

carving out the Transmission and Distribution functions of the

erstwhile Karnataka Electricity Board [5].

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.

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 [1], 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”.

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, 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. SCADA IMPLEMENTATION IN 220KV

SUBSTATION

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 1: (i) Process level (ii) Bay level (iii) Station level

Fig 1: Levels defined in IEC 61850 [1]

2.1 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.

2.2 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 2.

Station Level Functions: are of two types.

2.2.1 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.

2.2.2 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.

There are basically two types of equipment in a substation:

(i) Primary equipment’s and (ii) Secondary equipment’s.

2.3.2.1 Primary Equipment’s Include

Fig 2: Conceptual Substation Bays [1]

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 3.

Fig 3: Conceptual Substation Automation Topology [1]

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.

2.2.2.2. 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 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 4

shows RET670 IED.

Fig 4: RET670-Tansformer protection IED [8]

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

disturbance information. 30 apparatuses can be controlled and

visualized. Large HMI provides overview of quick status of

substation with position indications and service values [6].

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 5 shows

REC670 IED.

Fig 5: REC670 -Bay control IED [8]

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 [6].

REL670-Line Distance Protection IED: It provides versatile

protection, monitoring and control functionality with

maximum flexibility and performance optimized for

transmission 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.

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

Fig 6: REL670-Line distance protection IED [8]

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 [6].

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, 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 [6]. Figure 7 shows

REB670 IED.

Fig 7: REB670-Bus bar differential protection IED [8]

2.2.2.3. 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 8.

• 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

For SAS

220kV line

110kV line

11kV feeder

Fig 8: Layout of panels at Control center at 220/110/11kV

substation

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 9. 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 9: Connection of ABB panels at substation

As shown in figure 9 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.

2.2.2.4. SCADA 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 10(a), 10(b) and 10(c) respectively.

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

monitored by operator at control room. Same single line

SAS

SUX

Station

Auxiliary

Bay

Control

Panel

2BBA1

220kV Bus

Bar

Protection

Panel

2BBA2

220kV Bus

Bar

Protection

Panel

I

N

D

I 1

P

I

N

D

I

1

B

&

P

I

N

D

I

2

P

I

N

D

I

2

B

&

P

Bus

Coupler

B&P

T

R

F

1

H

V

B

&

P

T

R

F

1

L

V

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

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

Feeder

1&2

B&P

Feeder

3&4

B&P

Feeder

5&6

B&P



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 1 shows symbols used

for SCADA.

Table 1: Symbols used in SCADA Screen

Fig 10(A): Single Line Diagram Display of 220/110/11kv

Line at Control Room

Fig 10(B): Single Line Diagram Display of 110kv Line at

Control Room

Fig 10(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 11.

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.

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



Fig 11(a):220kV measurement values.

Fig 11(b):110kV measurement values.

Table 2 gives the incoming and outgoing voltage, current,

active & reactive power, power factor and frequency observed

on 220kV measurement monitoring screen on 07/07/2011 time

11.00.08.

2.3. Load Despatch Center:

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.

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 Centers (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 12.

Table 2: 220Kv Measurement Monitoring Values



Fig 12: A Typical Architecture of an Energy Management

System

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

DATE

07/07/2011

TIME

11.00.08

INDI-1

201

INDI-2

202

BC 203 TRAFO-

1 204

BGWD-

1 206

BGWD-

2 207

TRAFO-

2 208

Voltage in

kV

Vry 215.01 214.67 215.02 215.16 215.05 214.48 215.18

Vyb 217.42 217.59 217.76 217.37 217.63 217.21 217.37

Vbr 213.46 213.22 213.45 213.13 214.17 213.67 213.75

Current in

Ampere

L1 0.00 87.40 0.00 50.23 186.78 0.00 49.56

L2 0.00 89.90 0.00 51.67 192.67 0.00 51.32

L3 0.00 91.26 0.00 50.48 191.50 0.00 49.75

Active

power

MW 0.00 30.55 0.00 17.97 -66.39 0.00 17.75

Reactive

power

MVAR 0.00 13.54 0.00 5.95 -25.57 0.00 5.87

Power

factor

0.00 0.91 0.00 0.95 0.93 0.00 0.95

Frequency Hz 49.91 49.90 49.9 49.90 49.90 49.90 49.89



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).

SRLDC collects data from SLDC and controls Central

Generation. NLDC monitors all SRLDC and communicate

with Central electricity Authority (CEA).

2.3.1. 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 13: Monitoring screen for Karnataka state LDC [4]

At LDC, operator can observe generation, power flow,

schedule and actual energy available etc as depicted in figure

13.

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 14 shows

ABT Monitoring Screen at control center. UI charges are

decided by CEA.

Fig 14: ABT Monitoring Screen [4]

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.

2.4. Maintenance:

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 15 shows connection for improvement of earthing.



Fig 15: 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 3 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.

Table 3 : 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

3. CONCLUSION

Power Systems are large complex systems covering vast areas

National 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. On line monitoring,

operation and control of the modern day power systems is

required for maintaining system security, reliability, quality,

stability and ensuring economic operation,. The basic

requirement is of power system automation which is achieved

by SCADA.

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

such as voltage, current, frequency, active power, reactive

power and power factor. Operators at all substations will send

their respective load and energy required to the LDC. LDC

sends the required total load required by to SRLDC. SRLDC

according to available generation prepares load schedule and

send to LDC, this schedule must be followed by all stations.

During generation failure, availability of generation will be

updated to LDC; LDC will inform further it to all substations

so that proper load control can be carried out without any

interruption of power. In this way the total grid can be

observed and controlled, thus large gap between generation

and load is reduced. It also helps to perform energy billing,

energy audit and Availability Based Tariff(ABT) functions,

and Sub-system to perform Open Access operations at

LDC.SCADA has facilities to record data, event list,

disturbance records, and trip values during fault etc., with help

of these facilities operator at substation can analyze fault, if

any mistakes in recording readings can be easily sorted out.

Thus concluding that a full fledge SCADA system is very

much necessary for monitoring, controlling, fault detection

and prevention and to make restoration power supply activities

easier and faster.

REFERENCES

[1] KPTCL training report “Remote Substation Monitoring

And Control through SCADA”, 05-09 October 2009.

[2] Paper presented

[3] Martin Chartrand, “Dual Redundant Controller

Systems”, Control Microsystems White Paper, October

2004.

[4] Chandrashekar, Mallakkappa S “Integrated Extended

SCADA project KPTCL” IES Summary, October 31

2007.

[5] Manuals and website

[6] ABB RTU 560A Manual.

[7] www.kptcl.com and www.abb.com

BIOGRAPHY

Ms. Vinuta V Koluragi was born in

Bijapur, Karnataka, India. on 13th

July

1987. She obtained B.E degree in

Electrical & Electronics from B.L.D.E.A’s

http://www.kptcl.com/



Bijapur under VTU, Belgaum. She obtained M.Tech degree

in Power & Energy System from BEC Bagalkot under VTU,

Belgaum.

She is currently working as Assisstant Professor at

B.L.D.E.A’s V P Dr P. G. Halakatti College of Engg. &

Tech., Bijapur. Her areas of interest are Renewable Energy

Systems, PLC and SCADA,Control Systems, Power systems.

A Case Study on SCADA Implementation in 220 kV Substation

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