Sudan National Grid Monitoring System

Acknowledgements

    I would like to express my thanks to my supervisor Dr. A/Rahman A. Karrar, for his advice and generous assistance and encouragement during the whole course of this project.

And words of thanks to the N.E.C authorities and staff engineers who never hesitated to supply information that has generously helped me, and I am greatly indebted to Engineer Salah Elgabo, and Eng. Nasreldin F. Gali for their great help that steered this work to its final stages.

I have received continuous help and support through out the project from my colleague Eng. Yassin M. Yassin, who participated in data recording and in the program aspects of the study. I must also mention the Electronic Laboratory staff at the Department of Electrical Engineering, U. of K, who kindly permitted me to access all the laboratory facilities.

I would like to express my great thanks to the Sudanese Atomic Energy Commissions (SAEC), for their great help in the fabrication of the printed circuit board (PCB) designed in this project. Also I would like to express my thanks to the department of Information Technology in Mobil Company, for their great help in providing the communication equipment used in this project.

Finally, I reserve a special word of thanks for Austaz Saif Derrar, Dr. Mutasim A. Mahmoud, and Engineer Khalid M. Yassin for their willingness to provide help whenever needed.

Abstract

    The role of electrical energy is becoming more important in the energy supply of our society. This means that we are becoming more vulnerable to disturbances and power failures. Rising fuel costs and the increasing awareness of large environmentalist movements means that the scarce electrical power production resources for electric power must be utilized in the best way. This leads to a tighter interconnection, stricter joint operation between utilities and smaller operating margins. The flow of information plays a vital part in the secure and economic operation of the electrical utility.

The Sudan National Grid Monitoring System is a computerized system developed here for monitoring the status of the remote generation stations. The system represents an incomplete SCADA system (Supervisory Control And Data Acquisition). The monitoring is achieved by reading the desired data of the specified station that is transmitted to the central control building. There the data can be processed i.e. by recording, printing, ... etc.

The work done on this study was an experimental one, and the main target was to design and implement a monitoring system that utilizes most of the criteria needed for a small scale SCADA system.

The implementation of the system can be divided into three parts:

• The first part was concerned with the data acquisition and processing of the data at the remote station. For this part the required interfacing hardware was designed and fabricated in a Printed Circuit Board (PCB), and the software associated with it was programmed.
• The second part dealt with the communication system, i.e. the media, the protocol, and the equipment used. The hardware and software needed to achieve the communication system was developed.
• The last part was concerned with the database system needed for the recording of the received data. The database system also allows the data to be transferred to other programs for further studies and analysis. In general, this part describes and presents the skeletal of the database system for the NEC logging, reporting and analysis requirements.

The main obstacles confronted was the high cost of implementing such a system, so the trend was to make use of all available equipment and devices in order to bring the work to success. The study succeeded in that respect, and the targeted goal was achieved and a basis was made for the future design and implementation of a large SCADA system for the Sudanese National Grid.

Conclusions

Although the study was carried out on only one RTU representing Dr. Sharief Steam Power Station Unit 3, the outcomes of the study are valuable in formulating a general picture of the expected real time SCADA system to be implemented.

On the basis of what was done, and the study results, the following concluding remarks can be outlined:

1. The type of PC chosen for use at the RTU was an IBM XT or compatible. The aim of this was to use the cheapest PC to decrease the cost of the SCADA full-scale system implementation.
2. The hardware interface card to the PC computer for the 32 input signals was designed and fabricated. The interface card was subjected to continuous practical testing in the present power network. The results obtained were quite good and encouraging.
3. The software that reads the input channels of the interface card and sends them from the RTU to the central station was designed and programmed. The aim of the design was to make the program operates as a TSR which give the DOS (Disk Operating System) some of the features of multitasking. This enables the engineer at the RTU control room to use the PC in which the interface card is inserted to run any other program.
4. The generating machine features of Dr. Sharief Steam Power Station were studied and Unit 3 was selected to be the one for implementation of the RTU. Also the available signals and status indicator of Unit 3 were studied, and a selection of four signals was carefully made. The four chosen signals were the revolution per minute, the generator voltage, the generator current, and the output generated power.
5. A careful study was made of the present system of recording and logging the station data in the reports of the National Electricity Co-operation (NEC), and specifically the reports that concern Dr. Sharief Steam Power Station.
6. The communication system to be run at the central station was designed. The main aim of the communication system was to receive the data sent from the RTU. In the design of the communication system the protocol and data format was chosen. The duration of which the data is sent from the RTU to the central station was selected to be 2 minutes. The communication system was tested and gave good results, and the data was received correctly.
7. A database system was designed that ran at the central station. The main aim of this database system is to store the data received from the RTU in database files. These database files can be used by other programs that may be made in the future, or imported to Windowsä applications such as Microsoft Wordä and Microsoft Excelä for further analysis and forecasting studies to the system that are needed.
8. The database system automatically creates these database files when they are not found. And it generates a daily report for each station, this report will contain all the data received during the day. This data is logged by date and time, so a history of the station status is saved in a database file. This history is of valuable importance for the maintenance and rehabilitation of the machines in the stations.
9. The communication and database systems were included in one program package, and this package runs under Windowsä 3.x or Windowsä 95. Windowsä is an operating system that supports multitasking. This implies that the package made can be loaded while other programs were running.
10. The complete package contains a descriptive on-line help, that helps the user in configuring the program.
11. Two practical experiment were made and reports were printed out on two different days.

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