Fuzzy Switching Control of the Complete Oil Cycle of Shiraz Solar Power Plant

摘要

In this paper fuzzy control, PID switching and fuzzy switching control of the complete oil cycle of Shiraz solar power plant are presented. So far, in the literature, only modeling and control of the collectors' field of a solar power plant, which is a part of the complete oil cycle, have been studied. In this work the complete oil cycle is considered. Based on the layout of the oil cycle components, seven operational working loops are identified. According to various environmental conditions, disturbances and design constraints in some components, changes of working loop become necessary which cause switching in the continuous system.To control such a complex system, two controllers are required: 1- a continuous controller to hold outlet oil temperature of the collectors' field at its desired level and 2- a switching controller to determine suitable loop to be activated. In this paper, Fuzzy Switching is a new approach for decision making on switching actions between various loops which is used to prevent chattering phenomena which may be caused by conditional switching. For the complete controller structure of the system, two combinations of continuous and switching controllers are used: PID switching + Conditional switching and Fuzzy Logic + Fuzzy Switching. Simulation results show that applied control systems can manage the oil cycle in different situations especially in presence of large step disturbances (moving clouds). By applying such control systems, it is found that the behaviour of the controlled system is stable.