Power system management,

Graphical interface, Web application,

Client server architecture

Damir BLAŽEVIĆ[*]

Ninoslav SLAVEK[*]

Marina PEŠUT[*]

MANAGEMENT APPLICATION FOR DISTRIBUTED PRODUCTION SYSTEM ENVIRONMENT

Technical management of power transmission/distribution system is difficult and demanding process. Exact description of each object in power transmission system is necessary. Object's location, type and nature along with technical specification are information of crucial value in management and maintenance. Usually such information are catalogued and stored in database information system. Stored information are available to a smaller number of computer skilled employees due to information retrieving and presentation process.

Specially designed application for effortless data control and graphical validation of power transmission objects and systems is presented. Client-server architecture, cutting edge data driven web technology, native multiple access support and 24/7 availability makes it an excellent insight and support tool in power transmission/distribution system management. Web browser client side interface makes it suitable and ready for a variety of mobile appliances and technologies like hand held computers, mobile phones, etc.

  1. INTRODUCTION

Power transmission system (Croatian National Power Grid Company) is geographically spread and distributed production environment. Backbones of electrical power system are transmission power lines and power stations. There are over twenty power stations and more then thirty-five power line segments in local region. Detail information about power lines such as power line segment length, conductor material, maximum load, impedance etc. are crucial and it must be available to employees (management and maintenance) at any time. Power transmission system stations are objects where power is adjusted for further transmission or transformed for distribution facilities. Usually, distribution power facilities have power transformers, bus bars, circuit breakers, disconnectors, instrument transformers, surge arrestors as well as measuring, protection and communication equipment installed. For detail description of one power line segment a several dozen of data records is necessary. Information about power transmission station can occupy more then several hundreds of data records.

Such information concerning power lines and transmission power stations are catalogued and stored. Storage medium is hardcopy and/or database system. In case of a failure or regular maintenance some equipment are replaced and the new one are installed. According to this, stored information about transmission system also must be altered. Accurate and up to date information about the system and systems objects are necessary. Access to data base system is restricted to a smaller number of computer skill employees due to information retrieving and presentation process.

As mentioned above, power transmission system is consisted of great number of objects and information management is rather difficult but necessary task. This article describes application specially developed to ease the information management in such environment. The goals for this project are as follows: 24/7 availability, multiple simultaneous users, user-friendly environment and simplification of all tasks so that it can be operated with minimum computer skills.

In following section basic architecture and system design of developed application is reviled. Graphical user interface and its features are described in section 3. Future development guidelines and possible use of an application in other industry segments is presented in the last section.

  1. BASIC APPLICATION ARCHITECTURE

The basic goal put in front of a development team was to ensure the availability, multiple simultaneous access and simple use of an application. Every user needs to have up to date information access and system operator's updates are immediately deployed. To ensure the above goals client sever architecture in intranet environment is selected. Chosen technology will allow any user (local or remote) to gain access to application through internet at any time as long as user possess internet connection and application is running.

Application architecture consisted of web server, application server, data base driver and data base management system is shown in Fig. 1. User initially connects to the web server using only web browser (Internet Explorer, Mozilla, Netscape etc.). Web server replies and authorization process begins. After successful authorization process user is able to access the application and information stored in data base management system.

Fig. 1. Applications basic architecture

Varieties of options for user connection are shown in Fig. 2. Remote users can be connected through any existing Internet access technology (POTS, ISDN, xDSL, Mobile Services etc.).

Fig. 2. User access

Two basic user rights levels are defined. The operator level witch allows operator user to select, update, insert information and create new objects. Basic user is capable of retrieving information only.

Graphical user interface used for information presentation is described in the following section.

  1. GRAPHICAL ENVIRONMENT

Application's user interface is specially designed according to the customer's requests. Most of the graphics (data driven content) are made with the Macromedia Flash technology to ensure scalable vector graphics.

Fig. 3. Basic information window

Application's static frame is developed as standard html page. Basic information window is shown in Fig. 3. It is possible to recognize simple command bar at the top of the window containing basic command features as select, draw power line, create new power station object, zoom in, zoom out, delete and save. Power stations are represented with blue circles and power lines are represented with black lines. Shown window is also called level one information window because it represents the first and fundamental information about the power transmission system.

Click at the yellow line at the right corner opens additional information window witch purpose is to give more information about selected object and object under the "on mouse over" event. Mentioned above is showed in Fig. 4.

Fig. 4. Additional information window

Double click on selected power line bring us the pop up window represented in Fig. 5.

Fig. 5. Detail information about specific power line segment

Double click on a selected power station lead us to the information level two as shown in Fig. 6. Schematic drawings of power station are stored here. It is possible to see every object installed inside selected power station. Objects can be recognized as bus burs, circuit breakers, disconnectors, energy transformers, instrument transformers, etc.

Fig. 6. Power station's information level two

Double click on a selected object brings pop up window containing detail information about desired object as shown in Fig. 7. Information contained here allows user an insight to nature of device, its type, model, location, manufacturer, default voltage, current, power and all other necessary information about selected object. The amount of information contained in this pop up may vary according to the object's nature and type.

Fig. 7. Detail information about selected object at level two

When system operator is assigned to enter information about new power station it is necessary to create a power station object at information level one. Entering level two and drawing an electrical schematic follows. Possible scenario for altering and/or creating a new power station schematic is shown in Fig. 8. It is possible to see that additional information window is turned in to a toolbox containing predefined drawing objects witch are easily dragged into the drawing area.

Fig. 8. Schematic editor

After its first deployment Graphical Environment Application for Power Transmission Management System was suppress under several series of demanding tests. The experts of the Power System Department at Faculty of Electrical Engineering Osijek performed most valuable tests focusing on the simple and efficient use of an application.

  1. CONCLUSION

Next step in applications life cycle is to deliver and deploy it to the Croatian National Grid Company. Application will be on a trail use for a certain amount of time so it can be tested in a real production environment. Additional features will be added according to the customer's actual needs. For instance GPS features are planed to add in next release. Also it is possible to include some data gained through on line monitoring and telemetric equipment.

Expected benefits of applications use are more then obvious. With this system operational every employee is up to date information access granted. All system information is available in seconds to multiple simultaneous users. All above reduces time for gathering and deployment of information resulting in time and money preservation.

The full impact of presented management application on production system and operations is rather difficult to anticipate due to novelty of an approach and the fact that there are no similar systems in mentioned production environment.

With a small effort it is possible to adopt presented application for use in other industries. For example, district gas and heating system, water supply and other demanding distributed systems.

REFERENCES

[1] JOVIĆ F., FILIPOVĆ M., BLAŽEVIĆ D., SLAVEK N., Condition Based Maintenance in Distributed Production Environment, Machine Engineering 4 (2004), 1-2;180-192.

[2] JAGNJIĆ Ž., SLAVEK N., BLAŽEVIĆ D., Condition Based Maintenance of Power Distribution System, The 5th EUROSIM Congress on Modeling and Simulation, Marne la Vallee: ESIEE groupe, 2004.

[3] SLAVEK N., JOVIĆ F., BLAŽEVIĆ D., Quality Factors for the Real-time Embedded and Safety-critical Software Systems, The 5th EUROSIM Congress on Modeling and Simulation, Marne la Vallee: ESIEE groupe, 2004.

[4] JOVIĆ F., SLAVEK N., BLAŽEVIĆ D., Development of a Model and Simulation in Decision Making Process, Proceedings of the 7th WSEAS International Multiconference CSCC, Corfu: WSEAS, 2003.

[5] JOVIĆ F., SLAVEK N., Toward Total Quality Management Model to Ensuring the Quality of Software, DAAAM International Scientific Book 2002, DAAAM International Vienna, 2002.

[*] Faculty of Electrical Engineering Osijek

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