The problems with the existing static excitation systems of SM in "Solvay Sodi" and other factories from the heavy industry in Bulgaria are the irrevocably old eqipment and old control schemes leading to decreases of the reliability, making the technological pozition a precarious element of the whole technological structure of the factory. In addition in this type of systems we are speaking of controlling heavy-duty powers over 1MW. On the other hand in contrast to the controllers, the synchronous motors (SM) are mostly with an unexhausted technological resource and their replacement would have been economicly unjustified. The performed technico-economical analyz in this case gave priority to the introduction of SES 320A RETROFIT with the following parameters:
1. Keeping the power elements - transformers, starting resistrance, power thyristor;
2. Complete change of the electronic controllers;
3. Extension of the technological possibilities of the system;
4. Adapting the SES to the requirements of technical safety standards for operatign the system;
5. Inclusion of SES / SM in an automated system for maintaining constant levels of the power factor of the energy system of the factory.
Constructivly SES 320A RF‚¬ RETROFIT is performed in a Rittal box with dimensions 1800x800x800mm (without the transformer), with practically one-side maintaince. The dimensions of the sysyems are caused by the use of power elements - thyristors, starting resisitance. In comparison the dimesions of SES 300Ãƒâ‚¬ are 1600x600x600mm.
The main functions of the SES controller and the visualization of the processes are carried out by Allen Bradley's MicroLogix 1200 industrial controller and PanelView 300 Micro. In the controller program are included PID regulators working at real time and a program following the starting and stopping processes.
The analogical part of the control of the system is constructed modolusly - drivers, controling the thyristors, measuremental and transformational modolus.
This project dramaticly increaces the reliability of the SES, reduces the diagnostics and repairs time, improves the visualization and makes the staff's work easier.
An important moment in the realized project is the settled power factor maintainig rhythm. The presence of synchronous powers makes it possible to develop an effectiv maintaining system. Using the abilities of MicroLogix 1200 for working in a network on a later stage the whole SM group will be included in the factory's enegry system for compensation of COS.