الفهرس Only 14 pages are availabe for public view
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Abstract
Electrostatic precipitators play an important role in environmental protection. This research is concerned with improving the performance of electrostatic precipitators. Controlling the currents inside the fields of the precipitator was the main purpose of this work. Measuring and thyristors- triggering circuits are built and connected to a high voltage unit feeding a field inside an electrostatic precipitator. Interfacing of the high voltage unit to a personal computer is accomplished using an interfacing card. A state-space model of the high voltage unit is practically identified. A PI optimal controller is designed to control the high voltage field current based on choosing the controller with the best practical result. A fuzzy logic controller that does not depend on the model is designed based on some knowledge and experience about the high voltage unit. The design of the fuzzy logic controller is improved by tuning the controller. Several experiments are done to ensure the validity of the control scheme. The results prove the potency of the fuzzy logic controller.
The thesis is composed of seven chapters. Chapter 1 is an introductory chapter containing some historical background and thesis objectives and thesis layout. Chapter 2 describes electrostatic precipitators in general. The chapter discusses theory of operation, fields of application, basic components of electrostatic precipitators and how they are energized and controlled. In Chapter 3, the electrostatic precipitator containing the high voltage unit to be controlled is described. Techniques for measuring feedback signals and triggering the thyristors feeding the unit are explained. The interfacing methods with a PC are shown. In Chapter 4, practical identification of the system around an operating point using a reliable technique is described. In Chapter 5, several optimal controllers for the unit are designed based on the identified model. The best design is chosen based on experimental results. Chapter 6 discusses fuzzy logic controller design for the high voltage unit. Attempts made to reach a design giving the system the most acceptable response are shown together with the experimental results. This proposed design is subjected to various experimental tests to ensure its validity. Chapter 7 contains the conclusions with recommendations for future work.