Architecture and driver section of software system for electrical power systems management.

Moraru, Sorin Aurel ; Sisak, Francisc ; Cinca, Cristian 等

Abstract: Today many industrial facilities have a lot of industrial control software systems used in various ways. These systems work in all kinds of architectures, starting from the simple "one application on one computer attached to a process" to more complex systems such as client-server-database, multi-tier applications, etc. The system created by us has three main levels of application: (i) The data source, having two main parts: software applications that communicate with the equipment and a connector to the system; (ii) The server, gathering all the data from the data sources, processing and storing it into the database; (iii) The client applications, including the interface of the system with the user. There are detailed the driver and server sections.

Key words: software system, power systems management, communication protocol, monitoring.

1. INTRODUCTION

Industrial software applications have an important role in improving very consistently the work efficiency in industry. The effectiveness of industrial electronics is increased by remote control of processes.

Distributed applications systems allow very easy access to the information, by simply using a web-browser (such as internet explorer), from any computer which can communicate, through LAN or internet, with the application servers that manage all the information into a unified manner (Moraru et al., 2005).

In this paper we introduce a software system for electric power management, which we have developed to meet the new trends in information management and communications.

2. STATE OF THE ART

The importance of software remote surveillance is provided in papers such as (Rolim et al., 2006), where the authors present an analysis and software implementation of a robust synchronizing circuit, designed for use in the controller of active power line conditioners, and (Cho et al., 2005), where the authors present an automatic vision-based system for the quality control of web textile fabrics.

The need for interoperability is prominent in the industrial enterprise environment. Different applications and systems that cover the overall range of the industrial infrastructure from the field to the enterprise level need to interoperate.

In the article (Kalogeras et al., 2006) there is described a distributed system architecture that utilizes dominant state-of-the-art standard technologies in order to address the above issues in an efficient way.

The based remote control scheme for networked control systems is presented from the point of view of the quality-of-service (QoS) in the paper (Lee et al., 2006).

The important issue of an energy monitoring system, consisting of a digital energy meter, a supervisor and manager software, and a database to store the measurements, is treated in the paper (Libano et al., 2006).

3. OUR MONITORING SOLUTION

3.1. The advantages of our software system for power management are:

* Unified manner for managing and maintaining the data and information resulted from processing;

* The possibility to have secured access to the information from anywhere (using the fixed or mobile communication networks);

* The reduced costs for using the additional software needed to run our system, which can even be reduced to zero by using free and open-source technologies, starting with the server and finalizing with the visual components presented to the user.

* The possibility to implement the exact requests that the clients may have, depending on their needs;

* The modules that compose the system can be used independently, or can be connected together as needed. This is possible by using high performance and compatible technologies.

* The system is completely scalable and flexible.

3.2. Monitoring industrial equipments

Generally speaking, the industrial equipments deliver data into a cryptic form, hard to be interpreted by a human operator, especially when the amount of data is huge. The raw data, acquired from the equipment by special programs that run on Personal or Process Computers, must be processed in order to be transformed in useful and human readable information.

By using our system, viewing such information is being done on any computer in the factory, if that computer is connected in the same network with the main server. The information is processed in order to make it contain the maximum amount of information into a form that is as easy as possible to be interpreted by humans.

4. THE SYSTEM AND RESULTS

4.1. The hardware system

The electric cells (SEPAM and PECA type), connected to the power consumers (6.4 and 0.4 KV), are grouped within the production sectors at two big cement factories, measuring the phase voltages, phase currents, frequency, power factor, active energy and reactive energy.

For each group, we realized RS485 serial connection between the cells and, by optic fibers and specific converters RS485/FO, FO/RS485 and RS485/RS232, the connection to LAN computers through RS232 serial port. The data is passed through the driver computers to the server and database computers.

4.2. The software application levels in the monitoring system

The monitoring system is organized in three levels:

* On the first level we have the Driver programs, which gather the raw data from the industrial network of counters using the serial port (the data can be acquired by other ways as well).

* On the second level we have the Server application, which centralizes, unifies and processes the raw data received from the Drivers, with which it communicates using a local network (LAN) or the Internet.

* The third level is represented by the Client applications, which are accessed by the user through a web-browser, such as Internet Explorer. These connect to the server and get the information required by the user, which can select certain criteria, and presents it back to the user into a human readable form.

4.3. Connecting the Driver to the electric-cell network

The Driver allows the use of any serial port, with the possibility to customize the communication parameters as needed. The customization is being done using the upper-left combo-boxes located in the driver's main window, presented in the upper line of the Fig. 1.

After setting the serial port communication parameters and choosing the serial port, you can press the "open port" button, to open the serial port for communication. If the parameters are not correct, you must close the serial port by clicking the "close port" button. Then, you can set other parameter values and try to reopen the port with the new configuration. In order to be open-able, the serial port must be free (no other application that runs on the computer uses it). In the Fig. 1, the area marked with a red rectangle represents the controls associated with the serial connectivity section. This section implements the whole set of reading functions from the JBUS protocol and it is very useful in testing the electric-cells for verifying if these work correctly from the serial communications point of view.

The event log section represents an event log and is the mechanism by which the Driver sends feedback on the status and events to the human operator. The received information, events and errors are listed in the zone marked with red.

The monitoring section has the role of controlling the monitoring process for the electric-cells network to which the driver is connected. In the "Counters" field will be specified the electric-cells network addresses that will be monitored with this driver. The Driver's monitoring module will acquire data from the counters in the order in which they are in the list specified here.

[FIGURE 1 OMITTED]

After all the data from all the specified addresses has been read, the whole data acquisition process will start again from the first address.

The delay between acquisitions from individual counters is set in milliseconds in the "Time to wait between readings [ms]" field.

The timeout for waiting an answer from a counter represents the period of time, in milliseconds, which passes from the sending of a request to a counter until the response from that counter is received and processed.

The server communication section is used for managing the driver's connection with the server. Independently from the connection with the electric-cells network and the monitoring process, the driver can be connected or disconnected from the server. The condition to be met in order to successfully connect the driver to the server is that the server is started and the driver knows the server address. The driver allows changing the address and port at which the server is located.

If the driver can make the connection with the server, the "disconnect from server" button will be activated and a message confirming the successful connect operation will be listed in the log. If the connect operation fails and "auto connect" is checked, the driver will keep trying to connect to the server until it succeeds. This is useful when the server is restarted, because all the drivers will automatically reconnect and then the server is available. Data communicated on the serial port section presents the most recent data sent and received on the serial port, as specific to the JBUS protocol telegrams.

5. CONCLUSION

The proposed system architecture can provide very powerful tools to control the resources of an industrial enterprise, while maintaining low costs in the implementation of such a system. Having an integrated software tool as industrial control system eliminates the problems related to administrating different solutions and reduces the effort in personnel training.

6. REFERENCES

Cho, C.-S.; Chung, B.-M. & Park, M.-J. (2005). Development of Real-Time Vision-Based Fabric Inspection System. IEEE Trans. on Industrial Electronics, vol. 52, no. 4, pp. 1073 - 1079.

Kalogeras, A.P.; Gialelis, J.V.; Alexakos, C.E.; Georgoudakis, M.J. & Koubias, S.A. (2006). Vertical Integration of Enterprise Industrial Systems Utilizing Web Services. IEEE Trans. on Industrial Informatics, vol.2, no. 2, pp. 120-128.

Lee, K.C.; Lee, S. & Lee, M.H. (2005). QoS-Based Remote Control of Networked Control Systems Via Profibus Token Passing Protocol. IEEE Trans. on Industrial Informatics, vol. 1, nr. 3, pp. 183-191.

Libano F. et al. (2006). Power Energy Meter in a Low Cost Hardware/Software. 2006 IEEE International Symposium on Industrial Electronics, pp. 1712 - 1715, Digital Object Identifier: 10.1109/ISIE.2006.295828.

Moraru, S.A.. Pelcz, A.. Bujdei, C. & Perniu, L. (2005). Web-oriented Applications of Databases Used in Electrical Domain. The 14th International Scientific and Applied Science Conference Electronics' 2005, Sozopol, Bulgaria, book 3, ISBN 954-438-519-3.

Rolim, L.G.B.; da Costa Jr., D. R. & Aredes, M. (2006). Analysis and Software Implementation of a Robust Synchronizing PLL Circuit Based on the pq Theory. IEEE Trans. on Industrial Electronics, vol.53, no. 6, pp. 1919-1926.