上海交通大学：《电力系统自动化》课程教学资源（推荐论文）Design, development, and commissioning of a supervisory control and data acquisition（SCADA）laboratory for research and training

1582 IEEE TRANSACTIONS ON POWER SYSTEMS.VOL.19,NO.3.AUGUST 2004 Design,Development,and Commissioning of a Supervisory Control and Data Acquisition (SCADA) Laboratory for Research and Training Mini S.Thomas,Senior Member;IEEE,Parmod Kumar,and Vinay K.Chandna Abstract-This paper reports a state-of-the-art Supervisory to large amounts of current information from the data highway. Control and Data Acquisition (SCADA)Laboratory facility for and also past history from the archived data storage.The system power systems at Jamia Millia Islamia,New Delhi,India.It has engineer can also readily install new hardware for on-line data been designed to function as a research and training center for utilities,faculty members,and students.This paper covers the acquisition and control. design,commissioning,and functioning of the SCADA/EMS The SCADA/EMS laboratory has been set up with the view laboratory facility,based on distributed-processing technology. of providing students and practicing engineers with hands on The SCADA laboratory will provide hands on experience to learning experience on SCADA system,and its applications to students and practicing engineers and will give them an insight into the contemporary SCADA systems.This lab is the first of its the management,supervision and control of an electric power kind to be functional in India. system.The setting up of this laboratory is of utmost importance because SCADA systems,though used extensively by the indus- Index Terms-DCS,energy management system (EMS),eth- ernet,intelligent control,laboratory,real-time systems,SCADA tries,are the proprietary item of each company and hence very systems. few technical details are available to students and researchers. This laboratory is providing research facilities in the form of hardware and software for adaptive and intelligent control of in- I.INTRODUCTION tegrated power systems.Research work on preprocessing data N LECTRICAL power is one of the most important infra- at the RTU level using Fuzzy Logic and Fuzzy-Genetic algo- structure inputs necessary for the rapid socio-economic rithm has already earned recognition [2],[3.The significance development of a country.Currently,it constitutes about 20% of the laboratory is highlighted by the developments in substa- of the total annual energy consumption on a worldwide scale tion automation,which is revolutionizing the automation sce- with an ever-rising demand.This increase in demand has led to nario in power systems [4].One of the unique features of the the installation and incorporation of a large number of electrical SCADA/EMS laboratory,that makes it the only one of its kind, power generation units with increased capacities in a common is the use of a distributed processing system,which supports a power grid,making the operation of the entire system sensitive global database.The use of such a system was favored against to the prevailing conditions.Therefore,the extensive and com- that of personal computers with data acquisition add-on cards plex power systems have become unmanageable using the con- [5-[7],in order to acquaint students with the standard indus- ventional instrumentation and control schemes.Intelligent sys- trial practices.Earlier reports on SCADA systems are limited to tems based on microprocessors and computers have been em- the description of a Greek EMS-SCADA implementation and ployed for online monitoring and control of modern large-scale application of ATM based networks [8],[9]. power systems [1],in generation,transmission and distribution, thereby overcoming the complexities and drawbacks of the con- II.DESIGN OF THE LABORATORY ventional instrumentation schemes. Such an integrated power system thus needs a large amount Large SCADA systems are used in a wide range of applica- of data to be acquired,processed and presented to the operator tions like power station control,transmission,distribution au- and the system engineer for effective operation of the power tomation,and smaller SCADA systems are used for industrial grid.These functions can be handled very effectively using a automation.In the proposed lab we wanted to give a general idea distributed processing system.It provides the system engineer about SCADA systems which would be applicable to any of the and operator with a powerful tool,which gives immediate access above mentioned processes,in particular for substation automa- tion.Hence designing the specifications for the laboratory was quite challenging and satisfying. Manuscript received November 10.2003.The work of the first author was supported by the All India Council for Technical Education (AICTE). SCADA for power systems,distributed in wide geographical M.S.Thomas is with the Electrical Engineering Department,Jamia Millia areas,is an integrated technology comprising of the following Islamia,Jamia Nagar,New Delhi,India 110025 (e-mail:mini@ieee.org). P.Kumar is with the Department of Electrical Engineering,Delhi College of four major components [10]: Engineering,Delhi,India 110042 (e-mail:pramodk2003@yahoo.co.in). i)Master Station:It is a collection of computers,periph- V.K.Chandna is with the Electrical Engineering Department,Inderprastha erals and appropriate input/output (I/O)systems that Engineering College,Sahibabad,Ghaziabad(UP),India 201010 (e-mail:vinay- chandna@yahoo.co.in). enable the operators to monitor the state of the power Digital Object Identifier 10.1109/TPWRS.2004.826770 system (or a process)and control it. 0885-8950/04$20.00©2004EEE

1582 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 19, NO. 3, AUGUST 2004 Design, Development, and Commissioning of a Supervisory Control and Data Acquisition (SCADA) Laboratory for Research and Training Mini S. Thomas, Senior Member, IEEE, Parmod Kumar, and Vinay K. Chandna Abstract—This paper reports a state-of-the-art Supervisory Control and Data Acquisition (SCADA) Laboratory facility for power systems at Jamia Millia Islamia, New Delhi, India. It has been designed to function as a research and training center for utilities, faculty members, and students. This paper covers the design, commissioning, and functioning of the SCADA/EMS laboratory facility, based on distributed-processing technology. The SCADA laboratory will provide hands on experience to students and practicing engineers and will give them an insight into the contemporary SCADA systems. This lab is the first of its kind to be functional in India. Index Terms—DCS, energy management system (EMS), eth￾ernet, intelligent control, laboratory, real-time systems, SCADA systems. I. INTRODUCTION ELECTRICAL power is one of the most important infra￾structure inputs necessary for the rapid socio-economic development of a country. Currently, it constitutes about 20% of the total annual energy consumption on a worldwide scale with an ever-rising demand. This increase in demand has led to the installation and incorporation of a large number of electrical power generation units with increased capacities in a common power grid, making the operation of the entire system sensitive to the prevailing conditions. Therefore, the extensive and com￾plex power systems have become unmanageable using the con￾ventional instrumentation and control schemes. Intelligent sys￾tems based on microprocessors and computers have been em￾ployed for online monitoring and control of modern large-scale power systems [1], in generation, transmission and distribution, thereby overcoming the complexities and drawbacks of the con￾ventional instrumentation schemes. Such an integrated power system thus needs a large amount of data to be acquired, processed and presented to the operator and the system engineer for effective operation of the power grid. These functions can be handled very effectively using a distributed processing system. It provides the system engineer and operator with a powerful tool, which gives immediate access Manuscript received November 10, 2003. The work of the first author was supported by the All India Council for Technical Education (AICTE). M. S. Thomas is with the Electrical Engineering Department, Jamia Millia Islamia, Jamia Nagar, New Delhi, India 110025 (e-mail: mini@ieee.org). P. Kumar is with the Department of Electrical Engineering, Delhi College of Engineering, Delhi, India 110042 (e-mail: pramodk2003@yahoo.co.in). V. K. Chandna is with the Electrical Engineering Department, Inderprastha Engineering College, Sahibabad, Ghaziabad (UP), India 201010 (e-mail: vinay￾chandna@yahoo.co.in). Digital Object Identifier 10.1109/TPWRS.2004.826770 to large amounts of current information from the data highway, and also past history from the archived data storage. The system engineer can also readily install new hardware for on-line data acquisition and control. The SCADA/EMS laboratory has been set up with the view of providing students and practicing engineers with hands on learning experience on SCADA system, and its applications to the management, supervision and control of an electric power system. The setting up of this laboratory is of utmost importance because SCADA systems, though used extensively by the indus￾tries, are the proprietary item of each company and hence very few technical details are available to students and researchers. This laboratory is providing research facilities in the form of hardware and software for adaptive and intelligent control of in￾tegrated power systems. Research work on preprocessing data at the RTU level using Fuzzy Logic and Fuzzy-Genetic algo￾rithm has already earned recognition [2], [3]. The significance of the laboratory is highlighted by the developments in substa￾tion automation, which is revolutionizing the automation sce￾nario in power systems [4]. One of the unique features of the SCADA/EMS laboratory, that makes it the only one of its kind, is the use of a distributed processing system, which supports a global database. The use of such a system was favored against that of personal computers with data acquisition add-on cards [5]–[7], in order to acquaint students with the standard indus￾trial practices. Earlier reports on SCADA systems are limited to the description of a Greek EMS-SCADA implementation and application of ATM based networks [8], [9]. II. DESIGN OF THE LABORATORY Large SCADA systems are used in a wide range of applica￾tions like power station control, transmission, distribution au￾tomation, and smaller SCADA systems are used for industrial automation. In the proposed lab we wanted to give a general idea about SCADA systems which would be applicable to any of the above mentioned processes, in particular for substation automa￾tion. Hence designing the specifications for the laboratory was quite challenging and satisfying. SCADA for power systems, distributed in wide geographical areas, is an integrated technology comprising of the following four major components [10]: i) Master Station: It is a collection of computers, periph￾erals and appropriate input/output (I/O) systems that enable the operators to monitor the state of the power system (or a process) and control it. 0885-8950/04$20.00 © 2004 IEEE

THOMAS er aL:DESIGN.DEVELOPMENT.AND COMMISSIONING OF A SCADA LABORATORY FOR RESEARCH AND TRAINING 1583 包宣凰厚鸟马 Printer Data Highway Master Station AC800F Processor (DPU) AC800F Processor (RTU) EA Profibus Profibus Analog,Digital,Pulse Analog,Digital,Pulse 1/O Units L/O Units FIELD DEVICES FIELD DEVICES RTU-Remote Terminal Unit DPU-Distributed Processing Unit DPU RTU EA-Energy Analyzer OS-Operator Station ES-Engineering Station Fig.2.The DPU and the RTU Fig.1.Overview of the laboratory through the SCADA system,to enable the students to have a ii)Remote Terminal Unit(RTU):RTU is the "Eye,Ear and feel of a real power system. Hands"of a SCADA system.The RTU acquires all the The designing of the lab was done keeping in mind the indus- field data from different field devices,processes it and trial needs,as the laboratory will be used for training on the job engineers and fresh graduates. transmits the relevant data to the master station.At the same time,it distributes the control signals received from the master station to the field devices. III.SYSTEM ARCHITECTURE iii)Communication System:It refers to the communication The architecture of SCADA system used in the laboratory, channels employed between the RTU and the master sta- among the various processors connected to the data-highway, tion.The bandwidth of the channel limits the speed of is of distributed function type.Distributed architecture was pre- communication. ferred as this is modular and expandable in future.The SCADA iv)Human Machine Interface (HMI):HMI refers to the in- system used in the laboratory is microcomputer based with func- terface required for the interaction between the master tional and database distribution.It has open ended system ar- station and the operators/users of the SCADA system. chitecture comprising of the system hardware,the system soft- The proposed laboratory has all the above components of ware and human machine interface,which are discussed in de- the SCADA system with on-line monitoring control facili- tail below: ties as shown in Fig.1.The master station has two engineering consoles for project implementation and four operator consoles for system monitoring.The SCADA hardware includes a dis- A.System Hardware tributed processing unit (DPU),a remote terminal unit(RTU) The system hardware comprises of the processing units,the and a number of analog,digital and pulse input/output units and DPU and RTU,two engineering stations and four operator sta- field equipment. tions.Each of the hardware components is discussed in detail in The communication interface includes the Profibus and Sections IⅢ-B and C. Modbus modules,and the LAN in the laboratory is through 1)Distributed Processing Unit(DPU):The DPU is config- an Ethernet highway.The system software has the facility for ured around a 32-bit Restricted Instruction Set Computer easy online configuration for mimics,trends,reports etc.and (RISC)processor AC800F with 4 MB memory as shown for web navigation.An 11 KV substation,which is supplying in Fig.2.It can support up to 100 master less RTUs.At power to the Faculty of Engineering and Technology,is being present there is only a single RTU communicating to the monitored.The prototype model of a 765 KV transmission line DPU.The DPU has a capability of handling more than and on-load tap changer transformer(with auto-transformer and 1000 inputs and outputs,but it is presently configured stepper motor)have been developed,monitored and controlled for 216 inputs and outputs (digital,analog,and pulse)

THOMAS et al.: DESIGN, DEVELOPMENT, AND COMMISSIONING OF A SCADA LABORATORY FOR RESEARCH AND TRAINING 1583 Fig. 1. Overview of the laboratory. ii) Remote Terminal Unit (RTU): RTU is the “Eye, Ear and Hands” of a SCADA system. The RTU acquires all the field data from different field devices, processes it and transmits the relevant data to the master station. At the same time, it distributes the control signals received from the master station to the field devices. iii) Communication System: It refers to the communication channels employed between the RTU and the master sta￾tion. The bandwidth of the channel limits the speed of communication. iv) Human Machine Interface (HMI): HMI refers to the in￾terface required for the interaction between the master station and the operators/users of the SCADA system. The proposed laboratory has all the above components of the SCADA system with on-line monitoring & control facili￾ties as shown in Fig. 1. The master station has two engineering consoles for project implementation and four operator consoles for system monitoring. The SCADA hardware includes a dis￾tributed processing unit (DPU), a remote terminal unit (RTU) and a number of analog, digital and pulse input/output units and field equipment. The communication interface includes the Profibus and Modbus modules, and the LAN in the laboratory is through an Ethernet highway. The system software has the facility for easy online configuration for mimics, trends, reports etc. and for web navigation. An 11 KV substation, which is supplying power to the Faculty of Engineering and Technology, is being monitored. The prototype model of a 765 KV transmission line and on-load tap changer transformer (with auto-transformer and stepper motor) have been developed, monitored and controlled Fig. 2. The DPU and the RTU. through the SCADA system, to enable the students to have a feel of a real power system. The designing of the lab was done keeping in mind the indus￾trial needs, as the laboratory will be used for training on the job engineers and fresh graduates. III. SYSTEM ARCHITECTURE The architecture of SCADA system used in the laboratory, among the various processors connected to the data-highway, is of distributed function type. Distributed architecture was pre￾ferred as this is modular and expandable in future. The SCADA system used in the laboratory is microcomputer based with func￾tional and database distribution. It has open ended system ar￾chitecture comprising of the system hardware, the system soft￾ware and human machine interface, which are discussed in de￾tail below: A. System Hardware The system hardware comprises of the processing units, the DPU and RTU, two engineering stations and four operator sta￾tions. Each of the hardware components is discussed in detail in Sections III-B and C. 1) Distributed Processing Unit (DPU): The DPU is config￾ured around a 32-bit Restricted Instruction Set Computer (RISC) processor AC800F with 4 MB memory as shown in Fig. 2. It can support up to 100 master less RTUs. At present there is only a single RTU communicating to the DPU. The DPU has a capability of handling more than 1000 inputs and outputs, but it is presently configured for 216 inputs and outputs (digital, analog, and pulse)

1584 IEEE TRANSACTIONS ON POWER SYSTEMS.VOL.19,NO.3.AUGUST 2004 a power system,both during its normal functioning and under fault conditions,as this is the basic tool for fault diagnostics. 3)Input/Output Units:At present the system has 216 input/output channels,including that of both the DPU and RTU.The analog inputs comprise of the signals coming from the voltage and current transducers con- nected to the various field devices like the 3-phase transmission line,3-phase load,etc.The digital in- puts/outputs are the capacitor bank on/off positions in the substation and the circuit breaker positions on the transmission line and the load.Apart from these,there are pulse inputs and outputs. 4)Data Highway:The laboratory incorporates industry stan- Fig.3.The processor,with the Ethernet,Profibus,and Modbus modules dard networking.It has an Ethernet data highway(coaxial cable)operating at 10 Mbps and is currently supporting The RTU.DPU and the input/output units are intercon- a network of four operator stations and two engineering nected through the Profibus module,as shown in Fig.3. stations along with the DPU and the RTU,all connected The DPU has the Modbus module for dedicated commu- in bus topology.The DPU passes real time data to the op- nication with Intelligent Electronic Devices(IEDs). erator and engineering stations via the Ethernet through 2)Remote Terminal Unit(RTU):The SCADA/EMS labo- customized software.The I/O units are connected to the ratory has a single RTU that can be stationed at a re- processor through the Profibus.The Modbus module con- mote location.Presently in the absence of a sufficiently nects the Intelligent Electronic Device,the Energy Ana- remote field,the RTU is functioning inside the labora- lyzer,to the AC800F.The Modbus is incorporated in the tory itself.The RTU is also equipped with I/O channels system for performing dedicated tasks and for better un- (digital,analog and pulse)for capturing the field data, derstanding of the industrial buses. and has the modem for communicating on RS485 link. 5)Operator and Engineering Station:The SCADA system Like the DPU,the RTU is also configured around a 32-bit has six Pentium-IV Computers(running in the environ- RISC processor AC800F.The RTU communicates to the ment of Windows 2000)acting as the operator stations master SCADA system(DPU)through a Profibus.Since and engineering stations,so that,at a given time,a max- the DPU and RTU have the same hardware configuration imum of 10 students/trainees can work in the laboratory, and are at the same location,they can act as a redundant two on each station,one station is left for faculty members system at any time,to depict the actual control room ex- and R&D work.Each of the four operator stations pro- perience. vides a customized,interactive,graphic user interface,de- The DPU and RTU are currently performing the fol- signed using modern software programming techniques. lowing functions in the laboratory: The entire field can be monitored and controlled from a)Data acquisition,system monitoring and control: the operator stations.Presently,as the field equipments The DPU and RTU acquire data(digital,analog and being monitored are not very vast,each operator station pulse)from the field equipment connected to the covers the entire field,but in case of a vast field,each various input channels.These data are then passed operator station can be configured to perform dedicated on to the processor via the Profibus.The processor monitoring of different sections of the field. performs analytical calculations on these data and Two Pentium IV computers are serving as the engineering transmits them to the engineering and operator sta- stations for the system.The engineering station runs the engi- tions via the Ethernet.The various operators can neering software,programmed using Visual Basic 6.0.The com- thus monitor the field signals viz.voltage,current, missioning,adding new hardware,changing the tag settings,and frequency,temperature etc from the control room. associated tasks are performed at the engineering station using The DPU also has analog,digital and pulse output the engineering software modules,through which the operator can give con- trol signals from the operator station to the field de- vices,e.g.,a pulse output signal to rotate the stepper B.System Software motor. Currently,the laboratory utilizes two system software b)Sequence of Events Recording(SOE):All the data programs for better understanding and proper utilization of in the DPU comes with a time stamping.The scan the product available in the market.The first one is hardware rate for digital data is usually 2 ms and for analog specific and dedicated software,whereas the other one is an data it is 10 ms.The scan time can be set to0.5 ms,1 open-ended system software,which can communicate with any ms,2 ms etc.as per the process requirement.SOE hardware device.This is to make the laboratory much more will provide the students a clear understanding of generalized,rather than constrained to a specific hardware.The the various phenomena and events associated with SCADA software being used in the laboratory has provision

1584 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 19, NO. 3, AUGUST 2004 Fig. 3. The processor, with the Ethernet, Profibus, and Modbus modules. The RTU, DPU and the input/output units are intercon￾nected through the Profibus module, as shown in Fig. 3. The DPU has the Modbus module for dedicated commu￾nication with Intelligent Electronic Devices (IEDs). 2) Remote Terminal Unit (RTU): The SCADA/EMS labo￾ratory has a single RTU that can be stationed at a re￾mote location. Presently in the absence of a sufficiently remote field, the RTU is functioning inside the labora￾tory itself. The RTU is also equipped with I/O channels (digital, analog and pulse) for capturing the field data, and has the modem for communicating on RS485 link. Like the DPU, the RTU is also configured around a 32-bit RISC processor AC800F. The RTU communicates to the master SCADA system (DPU) through a Profibus. Since the DPU and RTU have the same hardware configuration and are at the same location, they can act as a redundant system at any time, to depict the actual control room ex￾perience. The DPU and RTU are currently performing the fol￾lowing functions in the laboratory: a) Data acquisition, system monitoring and control: The DPU and RTU acquire data (digital, analog and pulse) from the field equipment connected to the various input channels. These data are then passed on to the processor via the Profibus. The processor performs analytical calculations on these data and transmits them to the engineering and operator sta￾tions via the Ethernet. The various operators can thus monitor the field signals viz. voltage, current, frequency, temperature etc from the control room. The DPU also has analog, digital and pulse output modules, through which the operator can give con￾trol signals from the operator station to the field de￾vices, e.g., a pulse output signal to rotate the stepper motor. b) Sequence of Events Recording (SOE): All the data in the DPU comes with a time stamping. The scan rate for digital data is usually 2 ms and for analog data it is 10 ms.The scan time can be set to 0.5 ms, 1 ms, 2 ms etc. as per the process requirement. SOE will provide the students a clear understanding of the various phenomena and events associated with a power system, both during its normal functioning and under fault conditions, as this is the basic tool for fault diagnostics. 3) Input/Output Units: At present the system has 216 input/output channels, including that of both the DPU and RTU. The analog inputs comprise of the signals coming from the voltage and current transducers con￾nected to the various field devices like the 3-phase transmission line, 3-phase load, etc. The digital in￾puts/outputs are the capacitor bank on/off positions in the substation and the circuit breaker positions on the transmission line and the load. Apart from these, there are pulse inputs and outputs. 4) Data Highway: The laboratory incorporates industry stan￾dard networking. It has an Ethernet data highway (coaxial cable) operating at 10 Mbps and is currently supporting a network of four operator stations and two engineering stations along with the DPU and the RTU, all connected in bus topology. The DPU passes real time data to the op￾erator and engineering stations via the Ethernet through customized software. The I/O units are connected to the processor through the Profibus. The Modbus module con￾nects the Intelligent Electronic Device, the Energy Ana￾lyzer, to the AC800F. The Modbus is incorporated in the system for performing dedicated tasks and for better un￾derstanding of the industrial buses. 5) Operator and Engineering Station: The SCADA system has six Pentium-IV Computers (running in the environ￾ment of Windows 2000) acting as the operator stations and engineering stations, so that, at a given time, a max￾imum of 10 students/trainees can work in the laboratory, two on each station, one station is left for faculty members and R&D work. Each of the four operator stations pro￾vides a customized, interactive, graphic user interface, de￾signed using modern software programming techniques. The entire field can be monitored and controlled from the operator stations. Presently, as the field equipments being monitored are not very vast, each operator station covers the entire field, but in case of a vast field, each operator station can be configured to perform dedicated monitoring of different sections of the field. Two Pentium IV computers are serving as the engineering stations for the system. The engineering station runs the engi￾neering software, programmed using Visual Basic 6.0. The com￾missioning, adding new hardware, changing the tag settings, and associated tasks are performed at the engineering station using the engineering software. B. System Software Currently, the laboratory utilizes two system software programs for better understanding and proper utilization of the product available in the market. The first one is hardware specific and dedicated software, whereas the other one is an open-ended system software, which can communicate with any hardware device. This is to make the laboratory much more generalized, rather than constrained to a specific hardware. The SCADA software being used in the laboratory has provision

THOMAS er aL:DESIGN.DEVELOPMENT.AND COMMISSIONING OF A SCADA LABORATORY FOR RESEARCH AND TRAINING 1585 dtiICo Buder F fact Co Fancion cDE -8 OS (Window 2000/Window NT with OPC Server) gD回色☒a器回？ ☑ Freelance 2000 SCADA Portal (open-ended software) Digivis Digitool Digi DDE Digi Browse (Operator (Engg. module) module) 9 ☑ 00 IEC 61131-3 programming languages Fig.4.Software relational diagram. 从nA01P而9eN0100 for online configuration facilities like creation,modification, 到5孔a国彩空图万nuCon南ol可Docer Fe核 心5里50渊 and deletion of process parameters in database,mimics,trends and reports.A web navigator has been designed using Java, Fig.5.Functional block diagram for the transmission line monitoring. to enable process management via Internet.The software has secured control facilities for executing individual digital output software,as it has in the DPU.All the back end programming is points or group of predefined points with a single command. done in Digitool using functional blocks along with the appro- It is capable of supporting standard power system software priate logic functions.The typical Functional Block Diagram programs like MATLAB and EDSA. (FBD)is shown in Fig.5.Digitool is a highly extensive module The dedicated software used in the system,Freelance 2000. with several useful features such as visual and sound alarms, consists of two main modules:Digivis,the operator software trend display,time stamping etc.Report of all field alarms and and Digitool,the engineering software as shown in the soft- system alarms along with time stamping,description,state,and ware relational diagram in Fig.4.Digivis software offers a current value is generated.Alarms(visual as well as audio)can user-friendly graphical interface in accordance with MS-Win-be set and displayed as per the requirement.All unacknowl- dows standard.It provides a comprehensive,standard and edged alarms remain in flashing mode till they are acknowl- free display logging,graphics and display facilities including edged. trend archiving,system diagnostics,etc.Both free display Trend display is another useful tool of this software.By trend and graphic displays are user-defined and are created using display we mean the display of variation of different parame- the graphic editor in the Digitool.The archived trend and log ters such as voltage,current,frequency,temperature etc.with files are viewed using Digi Browse.Digi DDE(Dynamic Data time.The software can be configured to give both the past and Exchange)permits to convert data to ASCII format,making it the current trends.From these trends,we can predict the next readable by third party softwares. trend also.These trends appear in the form of colorful graphs The Digitool,also known as control builder,is operated in and can be given oscilloscopic form by choosing appropriate configuration mode where,the project is structured,configured, scales.This feature makes the software more user-interactive and documented.Configuration can be processed off-line.The This allows the students to reconstruct the sequence of events in project objects are assigned to the hardware structure as part of case of a fault. the system configuration,and can then be downloaded when the Open ended software:SCADA portal is an open system soft- connection is later made on-line.Digitool can handle all types of ware,which enables one to develop highly interactive HMI for IEC 61 131-3 programming languages like the Function Block remote control and PLC applications.It combines the unique Diagram(FBD),Instruction List (IL),Ladder Diagram (LD). usability features found in HMI with simple integration of con- and Sequential Function Chart(SFC). trol equipment and a variety of IED's.It can communicate with Once a field device is connected/wired to the appropriate locally and geographically distributed devices through commu- input or output channel,depending upon the type of signal,it nication protocols like OPC and Modbus.The applications in has to be configured in the software.Each signal coming from SCADA are based on object oriented principle.In the SCADA the field devices is allocated a tag at the DPU I/O channels.This lab,we have configured SCADA portal using both OPC and tag acts as an address for the signal and also gives an indication Modbus protocols. about the type of signal.For example the tag AIl_C1_DPU in- dicates an analog input (Al)connected to the first channel (1) C.Human-Machine Interface (HMI) of the first analog input unit(C1)of the DPU.When the pro- HMI refers to the communication between Man and Machine gramming is done for a signal,it is allocated the same tag in the and is of utmost importance in modemn computer based con-

THOMAS et al.: DESIGN, DEVELOPMENT, AND COMMISSIONING OF A SCADA LABORATORY FOR RESEARCH AND TRAINING 1585 Fig. 4. Software relational diagram. for online configuration facilities like creation, modification, and deletion of process parameters in database, mimics, trends and reports. A web navigator has been designed using Java, to enable process management via Internet. The software has secured control facilities for executing individual digital output points or group of predefined points with a single command. It is capable of supporting standard power system software programs like MATLAB and EDSA. The dedicated software used in the system, Freelance 2000, consists of two main modules: Digivis, the operator software and Digitool, the engineering software as shown in the soft￾ware relational diagram in Fig. 4. Digivis software offers a user-friendly graphical interface in accordance with MS-Win￾dows standard. It provides a comprehensive, standard and free display logging, graphics and display facilities including trend archiving, system diagnostics, etc. Both free display and graphic displays are user-defined and are created using the graphic editor in the Digitool. The archived trend and log files are viewed using Digi Browse. Digi DDE (Dynamic Data Exchange) permits to convert data to ASCII format, making it readable by third party softwares. The Digitool, also known as control builder, is operated in configuration mode where, the project is structured, configured, and documented. Configuration can be processed off-line. The project objects are assigned to the hardware structure as part of the system configuration, and can then be downloaded when the connection is later made on-line. Digitool can handle all types of IEC 61 131-3 programming languages like the Function Block Diagram (FBD), Instruction List (IL), Ladder Diagram (LD), and Sequential Function Chart (SFC). Once a field device is connected/wired to the appropriate input or output channel, depending upon the type of signal, it has to be configured in the software. Each signal coming from the field devices is allocated a tag at the DPU I/O channels. This tag acts as an address for the signal and also gives an indication about the type of signal. For example the tag AI1_C1_DPU in￾dicates an analog input (AI) connected to the first channel (1) of the first analog input unit (C1) of the DPU. When the pro￾gramming is done for a signal, it is allocated the same tag in the Fig. 5. Functional block diagram for the transmission line monitoring. software, as it has in the DPU. All the back end programming is done in Digitool using functional blocks along with the appro￾priate logic functions. The typical Functional Block Diagram (FBD) is shown in Fig. 5. Digitool is a highly extensive module with several useful features such as visual and sound alarms, trend display, time stamping etc. Report of all field alarms and system alarms along with time stamping, description, state, and current value is generated. Alarms (visual as well as audio) can be set and displayed as per the requirement. All unacknowl￾edged alarms remain in flashing mode till they are acknowl￾edged. Trend display is another useful tool of this software. By trend display we mean the display of variation of different parame￾ters such as voltage, current, frequency, temperature etc. with time. The software can be configured to give both the past and the current trends. From these trends, we can predict the next trend also. These trends appear in the form of colorful graphs and can be given oscilloscopic form by choosing appropriate scales. This feature makes the software more user-interactive. This allows the students to reconstruct the sequence of events in case of a fault. Open ended software: SCADA portal is an open system soft￾ware, which enables one to develop highly interactive HMI for remote control and PLC applications. It combines the unique usability features found in HMI with simple integration of con￾trol equipment and a variety of IED’s. It can communicate with locally and geographically distributed devices through commu￾nication protocols like OPC and Modbus. The applications in SCADA are based on object oriented principle. In the SCADA lab, we have configured SCADA portal using both OPC and Modbus protocols. C. Human–Machine Interface (HMI) HMI refers to the communication between Man and Machine and is of utmost importance in modern computer based con-

1586 IEEE TRANSACTIONS ON POWER SYSTEMS.VOL.19,NO.3.AUGUST 2004 trol systems.The HMI in the laboratory has been developed to make it highly descriptive,interactive and user friendly.This was done in order to enhance the student's perception of elec- trical power systems and their performance.The control ele- ments of the power system and other field devices are graphi- cally modeled on a color monitor.The graphics have been devel- oped in almost an exact replication of the real time field setup, depicting all the field devices exactly as their layout in the labo- ratory.The control fields have been designed in the form of but- tons having different color schemes for depicting different op- erating conditions such as red for"off"'and green for"on."The different visual alarms keep flashing on the top of the screen, till they are acknowledged.The HMI has been designed using both the softwares available,the Digivis and SCADA Portal. IV.FIELD DESIGN The foremost task in the designing of the laboratory was, defining the power system to be monitored and controlled.This Fig.6.Three phase transmission line setup with autotransformer and stepper motor with drive. was done taking into account adequate scope for expansion of the system in future,and the latest facilities available in in- TRANSMISSION LINE MODEL strumentation and monitoring areas.A number of big indus- trial houses involved in power system SCADA were contacted, 107 and detailed discussions were carried out with the experts in the field.Also a study of the available industrial SCADA systems was done.Finally,the power system to be monitored,the con- figuration of the laboratory and the specifications for the field 50喷 500 A device were finalized. VC The laboratory field presently comprises of the following: >>>>> An 11 KV Substation feeding the Faculty of Engineering CONTNUED building,Jamia Millia Islamia. ISOLATOR2 上2000 3 phase transmission line model,complete with reactive 50 A and capacitive compensation. ·Energy Analyzer Prototype model of on load tap changer (OLTC)using stepper motor and autotransformer. ISOLATOR3 L22000 RTD,level Sensors,transducers,contactors 9 AAmpere T0 DC MITAm单Cne迪 Substation monitoring:Provision has been made for the mon- itoring of an 11 kV/440 V substation at Jamia Millia Islamia. Fig.7.Transmission line model graphic. The substation is located about 150 m from the SCADA Lab- oratory.Exclusive cabling has been laid from the substation up to 230 V,5 A range.The parameters for a 10-section II-model to the SCADA Lab with proper grounding.Voltage,current,fre- were computed and the actual inductance values per section ob- quency,phase angle and power factor transducers have installed tained.The inductances were designed and wound in the lab it- and real time values from the L.T side(440 V)of the transformer self and the capacitors were obtained readymade.The entire sec- have been made available in the SCADA Lab.The substation has tion bearing the capacitance and the inductance was enclosed in 8 capacitor banks installed for power factor corrections,which wooden boxes with covers.After assembling the lines,testing are automatically switched on depending on the power factor.was done and satisfactory results were obtained with Ferranti The On/Off positions of the capacitors are also fed in the DPU effect and other line parameter studies.Each of the 3 phases of as digital inputs. the transmission line is connected via autotransformers.The iso- Three-phase transmission line:The transmission line model lators perform the switching operation and are energized from as shown in Fig.6 was built to simulate the real time transmis- the operator stations.Current and voltage transducers are con- sion conditions in the laboratory,so that students could get a nected to sense the incoming voltage and current of each phase hands on experience of phenomenon such as Ferranti Effect,depicting the current and potential transformers on the actual Series and shunt compensation etc.by performing experiments line.Fig.7 shows the transmission line graphics on the HMI on the system.The transmission line model kept in the labo- screen. ratory is a scaled down II-model of a 765 kV.2000 MW.300 To give the students a fair idea of control devices,a 10 kg-cm km long three-phase transmission line.The actual field param- torque stepper motor with autotransformer has been used as eters of the existing line were obtained and were scaled down an On-Load-Tap changer,connected to the transmission line

1586 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 19, NO. 3, AUGUST 2004 trol systems. The HMI in the laboratory has been developed to make it highly descriptive, interactive and user friendly. This was done in order to enhance the student’s perception of elec￾trical power systems and their performance. The control ele￾ments of the power system and other field devices are graphi￾cally modeled on a color monitor. The graphics have been devel￾oped in almost an exact replication of the real time field setup, depicting all the field devices exactly as their layout in the labo￾ratory. The control fields have been designed in the form of but￾tons having different color schemes for depicting different op￾erating conditions such as red for “off” and green for “on.” The different visual alarms keep flashing on the top of the screen, till they are acknowledged. The HMI has been designed using both the softwares available, the Digivis and SCADA Portal. IV. FIELD DESIGN The foremost task in the designing of the laboratory was, defining the power system to be monitored and controlled. This was done taking into account adequate scope for expansion of the system in future, and the latest facilities available in in￾strumentation and monitoring areas. A number of big indus￾trial houses involved in power system SCADA were contacted, and detailed discussions were carried out with the experts in the field. Also a study of the available industrial SCADA systems was done. Finally, the power system to be monitored, the con￾figuration of the laboratory and the specifications for the field device were finalized. The laboratory field presently comprises of the following: • An 11 KV Substation feeding the Faculty of Engineering building, Jamia Millia Islamia. • 3 phase transmission line model, complete with reactive and capacitive compensation. • Energy Analyzer • Prototype model of on load tap changer (OLTC) using stepper motor and autotransformer. • RTD, level Sensors, transducers, contactors Substation monitoring: Provision has been made for the mon￾itoring of an 11 kV/440 V substation at Jamia Millia Islamia. The substation is located about 150 m from the SCADA Lab￾oratory. Exclusive cabling has been laid from the substation up to the SCADA Lab with proper grounding. Voltage, current, fre￾quency, phase angle and power factor transducers have installed and real time values from the L.T side (440 V) of the transformer have been made available in the SCADA Lab. The substation has 8 capacitor banks installed for power factor corrections, which are automatically switched on depending on the power factor. The On/Off positions of the capacitors are also fed in the DPU as digital inputs. Three-phase transmission line: The transmission line model as shown in Fig. 6 was built to simulate the real time transmis￾sion conditions in the laboratory, so that students could get a hands on experience of phenomenon such as Ferranti Effect, Series and shunt compensation etc. by performing experiments on the system. The transmission line model kept in the labo￾ratory is a scaled down -model of a 765 kV, 2000 MW, 300 km long three-phase transmission line. The actual field param￾eters of the existing line were obtained and were scaled down Fig. 6. Three phase transmission line setup with autotransformer and stepper motor with drive. Fig. 7. Transmission line model graphic. to 230 V, 5 A range. The parameters for a 10-section -model were computed and the actual inductance values per section ob￾tained. The inductances were designed and wound in the lab it￾self and the capacitors were obtained readymade. The entire sec￾tion bearing the capacitance and the inductance was enclosed in wooden boxes with covers. After assembling the lines, testing was done and satisfactory results were obtained with Ferranti effect and other line parameter studies. Each of the 3 phases of the transmission line is connected via autotransformers. The iso￾lators perform the switching operation and are energized from the operator stations. Current and voltage transducers are con￾nected to sense the incoming voltage and current of each phase, depicting the current and potential transformers on the actual line. Fig. 7 shows the transmission line graphics on the HMI screen. To give the students a fair idea of control devices, a 10 kg-cm torque stepper motor with autotransformer has been used as an On-Load-Tap changer, connected to the transmission line

THOMAS er aL:DESIGN.DEVELOPMENT.AND COMMISSIONING OF A SCADA LABORATORY FOR RESEARCH AND TRAINING 1587 model.The stepper motor has been mounted over the autotrans- of the parameters is maintained in the system.No external cir- former and can be driven by the operator console with pulse cuit/device is employed for this function as all the data coming inputs. from the DPU is already time stamped. A 3-phase resistive-inductive/capacitive load has been de- All the graphics as mentioned earlier have been designed in signed and developed to act as the power system load.Voltage an exact imitation of the actual field devices and their layout. and current transducers as well as contactors are connected be- The actual monitoring of the field is done through the Digivis tween the transmission line and the load to measure the voltage module of the software.The graphics are highly interactive and drop in the transmission line and also to perform switching op- easy to understand. erations of the load.The reactive and capacitive compensation A few of the experiments to be performed in the SCADA lab of the line during full load and light load conditions are clearly include on-line study and simulation of: demonstrated using the careful variation of the capacitive and 1)3-phase transmission line. inductive loads. 2)SOE fault diagnostics. Energy analyzer:A three-phase energy analyzer has been 3)Autotransformer tap positions connected to the incoming 3-phase supply through the Modbus 4)Static VAR compensation and Ferranti effect. module to the system.It can monitor up to 25 parameters and 5)Sub-station monitoring. is currently configured for the frequency,3 phase currents (a,I,Ic).three phase voltages (Va:V,Ve),power factor, real power and reactive power.It directly measures the phase VI.CONCLUSION and a neutral voltage,frequency,phase currents and computes other quantities such as voltage between lines,phase power The SCADA/EMS Laboratory has been designed and com- factors,phase active and reactive energies and three phase missioned to facilitate the understanding of real time monitoring system energies etc control of systems for Electrical Engineering students and professionals.The Laboratory is first of its kind where the stu- dents will get hands on experience on the on-line monitoring and control of the Electric Power System.The laboratory was con- V.COMMISSIONING ceived and designed after extensive consultation with Industries and utilities.The components of SCADA systems,master sta- Commissioning of the laboratory involved the following main tion,RTU,different communication channels and a variety of tasks: field equipments are available in the laboratory.The data ac- physical wiring of the devices; quisition is with time stamping,which will lead to sequence ·grounding; of events monitoring.A 3-phase transmission line model with ·tag allocation; on-load tap changer and static VAR are the highlights of the software customization: field equipments.The laboratory gets on-line data from the 11 ·graphic design. KV substation feeding the Faculty of Engineering.The labo- Once all the field devices including the transmission line ratory has two engineering stations and four operator stations model were finalized and obtained in the laboratory,the main at present,with 216 input/output units,which can be expanded task was to connect them to the DPU and provide proper to 1000.Overall,this laboratory will provide the undergraduate grounding schemes.The connection of the various analog and and postgrauduate students with a better understanding of indus- digital devices to the different input/output channels in the trial SCADA systems,especially as SCADA systems at present DPU has already been described in Sections II-IV.Ferrules are proprietary items of each company.It is proposed to add re- bearing the appropriate tags have been attached to all the dundant data highway using fiber optic cable soon. wires connecting the devices to the I/O channels,for easy The SCADA Laboratory will be primarily used for regular identification and tracing,in case any change has to be made. research and training programs for the benefit of Faculty and The entire system has been earthed as per industrial standards. students of Jamia,in order to give them hands on experience Tag allocation for various devices was an easy task as memory on SCADA systems.Another major emphasis is on doing in- mapping in the system is automatic and a device connected to dustrial consultancy and research for the benefit of Industrial the appropriate channel is identified by the system on its own houses.In addition,there will be regular training programs for and the users can provide the tag of their own choice. practicing engineers on SCADA systems.The courses will be Software customization was done by generating Functional modular and would suit both practicing and fresh engineers. Block Diagrams(FBD)for each of the field devices and then ap- Overall,the SCADA lab designing and implementation was a plying the appropriate logic.Audio and visual alarms were set challenging,passionate and fruitful experience. to indicate different conditions in the devices for,e.g.,when the transmission line current exceeds a particular limit,both audio ACKNOWLEDGMENT and visual alarms are generated.Graphical trends were gener- ated for constant monitoring of the different parameter changes The authors wish to thank S.Kumar,General Manager,ESPL. with time.Different parameters such as voltage,current,fre- for the necessary advice from time to time in implementation of quency etc.have been plotted in different colors for easy moni- this project.Thanks are also due to M/s ABB and M/s Industrial toring.Apart from the trends,a second by second record for each IT solutions for the help rendered

THOMAS et al.: DESIGN, DEVELOPMENT, AND COMMISSIONING OF A SCADA LABORATORY FOR RESEARCH AND TRAINING 1587 model. The stepper motor has been mounted over the autotrans￾former and can be driven by the operator console with pulse inputs. A 3-phase resistive-inductive/capacitive load has been de￾signed and developed to act as the power system load. Voltage and current transducers as well as contactors are connected be￾tween the transmission line and the load to measure the voltage drop in the transmission line and also to perform switching op￾erations of the load. The reactive and capacitive compensation of the line during full load and light load conditions are clearly demonstrated using the careful variation of the capacitive and inductive loads. Energy analyzer: A three-phase energy analyzer has been connected to the incoming 3-phase supply through the Modbus module to the system. It can monitor up to 25 parameters and is currently configured for the frequency, 3 phase currents , three phase voltages , power factor, real power and reactive power. It directly measures the phase and a neutral voltage, frequency, phase currents and computes other quantities such as voltage between lines, phase power factors, phase active and reactive energies and three phase system energies etc. V. COMMISSIONING Commissioning of the laboratory involved the following main tasks: • physical wiring of the devices; • grounding; • tag allocation; • software customization; • graphic design. Once all the field devices including the transmission line model were finalized and obtained in the laboratory, the main task was to connect them to the DPU and provide proper grounding schemes. The connection of the various analog and digital devices to the different input/output channels in the DPU has already been described in Sections II–IV. Ferrules bearing the appropriate tags have been attached to all the wires connecting the devices to the I/O channels, for easy identification and tracing, in case any change has to be made. The entire system has been earthed as per industrial standards. Tag allocation for various devices was an easy task as memory mapping in the system is automatic and a device connected to the appropriate channel is identified by the system on its own and the users can provide the tag of their own choice. Software customization was done by generating Functional Block Diagrams (FBD) for each of the field devices and then ap￾plying the appropriate logic. Audio and visual alarms were set to indicate different conditions in the devices for, e.g., when the transmission line current exceeds a particular limit, both audio and visual alarms are generated. Graphical trends were gener￾ated for constant monitoring of the different parameter changes with time. Different parameters such as voltage, current, fre￾quency etc. have been plotted in different colors for easy moni￾toring. Apart from the trends, a second by second record for each of the parameters is maintained in the system. No external cir￾cuit/device is employed for this function as all the data coming from the DPU is already time stamped. All the graphics as mentioned earlier have been designed in an exact imitation of the actual field devices and their layout. The actual monitoring of the field is done through the Digivis module of the software. The graphics are highly interactive and easy to understand. A few of the experiments to be performed in the SCADA lab include on-line study and simulation of: 1) 3-phase transmission line. 2) SOE & fault diagnostics. 3) Autotransformer tap positions. 4) Static VAR compensation and Ferranti effect. 5) Sub-station monitoring. VI. CONCLUSION The SCADA/EMS Laboratory has been designed and com￾missioned to facilitate the understanding of real time monitoring & control of systems for Electrical Engineering students and professionals. The Laboratory is first of its kind where the stu￾dents will get hands on experience on the on-line monitoring and control of the Electric Power System. The laboratory was con￾ceived and designed after extensive consultation with Industries and utilities. The components of SCADA systems, master sta￾tion, RTU, different communication channels and a variety of field equipments are available in the laboratory. The data ac￾quisition is with time stamping, which will lead to sequence of events monitoring. A 3-phase transmission line model with on-load tap changer and static VAR are the highlights of the field equipments. The laboratory gets on-line data from the 11 KV substation feeding the Faculty of Engineering. The labo￾ratory has two engineering stations and four operator stations at present, with 216 input/output units, which can be expanded to 1000. Overall, this laboratory will provide the undergraduate and postgrauduate students with a better understanding of indus￾trial SCADA systems, especially as SCADA systems at present are proprietary items of each company. It is proposed to add re￾dundant data highway using fiber optic cable soon. The SCADA Laboratory will be primarily used for regular research and training programs for the benefit of Faculty and students of Jamia, in order to give them hands on experience on SCADA systems. Another major emphasis is on doing in￾dustrial consultancy and research for the benefit of Industrial houses. In addition, there will be regular training programs for practicing engineers on SCADA systems. The courses will be modular and would suit both practicing and fresh engineers. Overall, the SCADA lab designing and implementation was a challenging, passionate and fruitful experience. ACKNOWLEDGMENT The authors wish to thank S. Kumar, General Manager, ESPL, for the necessary advice from time to time in implementation of this project. Thanks are also due to M/s ABB and M/s Industrial IT solutions for the help rendered

1588 IEEE TRANSACTIONS ON POWER SYSTEMS.VOL.19,NO.3.AUGUST 2004 REFERENCES Parmod Kumar received the B.E.,M.E.,and Ph.D.degrees in 1972,1975,and [1]T.Cegrell,"Power system control technology,"in PHI(UK)Series in 1982,respectively. After post-graduation in measurement and instrumentation,he joined M.P. Control Engineering,1986. [2]P.Kumar,V.K.Chandna,and M.S.Thomas,"Intelligent algorithm for Electricity Board,M.P.,India,as an Assistant Engineer and commissioned telemetry and SCADA instruments at substations,power stations,and the pre-processing multiple data at RTU,"IEEE Trans.Power Syst.,vol.18, p.1566-1572,Nov.2003. central control room.In 1983,he joined the Central Electricity Authority as [3]- -"Fuzzy-genetic algorithm for pre-processing data at RTU,"IEEE a Dynamic System Engineer and designed and configured the load dispatch Trans.Power Syst.,vol.19,pp.718-723.May 2004. centers for electric utilities.Subsequently,he served on various capacities [4]J.D.McDonald,"Substation automation IED,integration&availability to Indian Railway Construction Company,ERCON,ESPL,ESTC,and then entered academic life in 1991.His area of interest is smart and intelligent of information,"IEEE Power Energy Mag.,vol.1,no.2,pp.22-31 Mar./Apr.2003. system design,operation,and control. [5]S.P.Carullo and C.O.Nwankpa,"Interconnected power systems lab oratory:A computer automated instructional facility for power system experiments,"IEEE Trans.Power Syst.,vol.17,pp.215-222,May 2002 [6]K.K.Tan,T.H.Lee,and C.Y.Soh,"Internet-based monitoring of Vinay K.Chandna graduated from Nagpur University,India,in 1994 in elec- distributed control systems-an undergraduate experiment,"IEEE Trans. Education.vol.45.pp.128-134,May 2002. tronics and power.and received the M.E.degree in power systems from Walc- [7]B.Qiu and H.B.Gooi,"Web-based SCADA display systems (WSDS) hand College of Engineering,Maharashtra,India,in 1997. His employment experience includes Walchand College of Engineering. for access via internet,"IEEE Trans.Power Syst.,vol.15,pp.681-686, May2000. Sangli (MAH),and Ramdeo Baba Kamla Nehru Engineering College,Nagpur [8]D.T.Askounis and E.Kalfaouglou,"The greek EMS-SCADA:From the (MAH).He is presently a Senior Lecturer with Inderprastha Engineering contractor to the user,"IEEE Trans.Power Syst.,vol.15,pp.1423-1427 College.Ghaziabad.His areas of interest are fuzzy logic,SCADA,design Nov.2000. operation,and control of systems. [9]S.-J.Huang and Chih-Chieh,"Application of ATM -BASED network for an integrated distribution SCADA-GIS system,"IEEE Trans.Power Syst,vol.17,Pp.80-86,Feb.2002. [10]"Fundamentals of Supervisory Systems,"IEEE Tutorial Course, 91EH0337-6PWR,1991. Mini S.Thomas(M'88-SM'99),graduated from the University of Kerala in 1984 and received the M.Tech.degree from the Indian Institute of Technology (IIT).Madras,in 1986 (both with gold medals)and the Ph.D.degree from IIT, Delhi,in 1991.All degrees were in electrical engineering. Her employment experiences include Regional Engineering College,Calicut. Kerala and Delhi College of Engineering,New Delhi.She is presently a Pro- fessor in the Faculty of Engineering,Jamia Millia Islamia,New Delhi.She has published over 30 papers in international/national journals and conferences.Her current research interests are in SCADA/EMS systems and intelligent protection of power systems. Dr.Thomas received the prestigious"Career Award"for young teachers,in- stituted by AICTE,Government of India,in 1999

1588 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 19, NO. 3, AUGUST 2004 REFERENCES [1] T. Cegrell, “Power system control technology,” in PHI (UK) Series in Control Engineering, 1986. [2] P. Kumar, V. K. Chandna, and M. S. Thomas, “Intelligent algorithm for pre-processing multiple data at RTU,” IEEE Trans. Power Syst., vol. 18, pp. 1566–1572, Nov. 2003. [3] , “Fuzzy-genetic algorithm for pre-processing data at RTU,” IEEE Trans. Power Syst., vol. 19, pp. 718–723, May 2004. [4] J. D. McDonald, “Substation automation IED, integration & availability of information,” IEEE Power Energy Mag., vol. 1, no. 2, pp. 22–31, Mar./Apr. 2003. [5] S. P. Carullo and C. O. Nwankpa, “Interconnected power systems lab￾oratory: A computer automated instructional facility for power system experiments,” IEEE Trans. Power Syst., vol. 17, pp. 215–222, May 2002. [6] K. K. Tan, T. H. Lee, and C. Y. Soh, “Internet-based monitoring of distributed control systems-an undergraduate experiment,” IEEE Trans. Education, vol. 45, pp. 128–134, May 2002. [7] B. Qiu and H. B. Gooi, “Web-based SCADA display systems (WSDS) for access via internet,” IEEE Trans. Power Syst., vol. 15, pp. 681–686, May 2000. [8] D. T. Askounis and E. Kalfaouglou, “The greek EMS-SCADA: From the contractor to the user,” IEEE Trans. Power Syst., vol. 15, pp. 1423–1427, Nov. 2000. [9] S.-J. Huang and Chih-Chieh, “Application of ATM -BASED network for an integrated distribution SCADA-GIS system,” IEEE Trans. Power Syst., vol. 17, pp. 80–86, Feb. 2002. [10] “Fundamentals of Supervisory Systems,” IEEE Tutorial Course, 91EH0337-6 PWR, 1991. Mini S. Thomas (M’88–SM’99), graduated from the University of Kerala in 1984 and received the M.Tech. degree from the Indian Institute of Technology (IIT), Madras, in 1986 (both with gold medals) and the Ph.D. degree from IIT, Delhi, in 1991. All degrees were in electrical engineering. Her employment experiences include Regional Engineering College, Calicut, Kerala and Delhi College of Engineering, New Delhi. She is presently a Pro￾fessor in the Faculty of Engineering, Jamia Millia Islamia, New Delhi. She has published over 30 papers in international/national journals and conferences. Her current research interests are in SCADA/EMS systems and intelligent protection of power systems. Dr. Thomas received the prestigious “Career Award” for young teachers, in￾stituted by AICTE, Government of India, in 1999. Parmod Kumar received the B.E., M.E., and Ph.D. degrees in 1972, 1975, and 1982, respectively. After post-graduation in measurement and instrumentation, he joined M.P. Electricity Board, M.P., India, as an Assistant Engineer and commissioned telemetry and SCADA instruments at substations, power stations, and the central control room. In 1983, he joined the Central Electricity Authority as a Dynamic System Engineer and designed and configured the load dispatch centers for electric utilities. Subsequently, he served on various capacities to Indian Railway Construction Company, ERCON, ESPL, ESTC, and then entered academic life in 1991. His area of interest is smart and intelligent system design, operation, and control. Vinay K. Chandna graduated from Nagpur University, India, in 1994 in elec￾tronics and power, and received the M.E. degree in power systems from Walc￾hand College of Engineering, Maharashtra, India, in 1997. His employment experience includes Walchand College of Engineering, Sangli (MAH), and Ramdeo Baba Kamla Nehru Engineering College, Nagpur (MAH). He is presently a Senior Lecturer with Inderprastha Engineering College, Ghaziabad. His areas of interest are fuzzy logic, SCADA, design operation, and control of systems