Application Study On Fuzzy PID Controller In Temperature Control System With Large Inertia And Time Delay

Temperature control system is widely used in every field of industrial control, such as steel mills, chemical plants, coal fired power plant and so on. The temperature control system always has large inertia and time delay and it is complicated and uncertain. Therefore, it requires advanced control technology and control theory.PLC temperature control system is the most widely used temperature control system at present, and PID controller was commonly used in this system. PID controller is a linear controller applied in linear system, in order to remain the control performance it must adjust parameters continually. However, the actual temperature control is usually nonlinear. Through the study we found that intelligent control algorithm will have better control output. MATLAB is so powerful that it contains a lot of advanced control algorithms, such as the self-tuning fuzzy PID control. If we could integrate the advantages of both will achieve better control output.The self-tuning fuzzy PID control adjusts three parameters of PID control adaptively based on fuzzy control. It makes parameters adjusted with the change of the controlled object, and has no effect the system at the same time. This paper is to use this algorithm to realize accurate control of temperature.An automatic temperature control system is designed in this paper based on Siemens S7-300PLC. It not only realized the real-time data communication between the PLC and MATLAB using OPC technology, but also achieves the goal of real-time monitoring, alarm and analysis take advantage of WinCC configuration software. The main work of this paper is as follows:This paper first introduces the research background and status of temperature control system, then introduces in detail the design, assembly and configuration process of the hardware system and software system, including hardware selection, commissioning, connection, the installation of software system, settings, etc. Finally, we use the MATLAB toolbox which has powerful and flexible programming ability to design an advanced self-tuning fuzzy PID controller and set up a control system model. Through the simulation, we achieved the purpose of automatic temperature control.This system combined with the PLC, MATLAB toolbox, and WinCC configuration software together. Through the communication and monitoring between them, it has realized the automatic control of temperature. The experimental results show that this structure is conducive to enhance the automation level of the system and improve the efficiency of the control. In addition, it has a profound practical significance and application value.