Research Of Fuzzy Control Based On PSO In Superheated Steam Temperature System

With the rapid development of science and technology, China’s thermalpower is moving in the direction of high parameters and large capacity, andrequirement of thermal automation is also rising. In various control objects ofthermal automation, superheated steam temperature control is one of the mainparameters, and too high or too low will has a direct impact on the safe andeconomic operation of the unit. According to the characteristics of superheatedsteam temperature with large delay, large inertia, time-varying and non-linear,this paper presents a fuzzy adaptive PID control system based on PSO, and it hasimportant theoretical and practical significance.The thesis firstly introduces the control task of the superheated steamtemperature system, and based on the detailed analysis of dynamic and staticcharacteristics, we select spary desuperheating way as means of controlapplication. Compared the commonly used method, we select cascade control asthe modeling program.For the shortcomings of the PID controller that the parameters can not bechanged once identified, we use the fuzzy PID controller as a cascade control ofthe main controller. Fuzzy adaptive PID controller takes error and error rate ofchange as input, and adjusts the parameters according to the fuzzy control rulesand membership function curve. Compared with conventional cascade control,simulation of fuzzy adaptive PID control of superheated steam temperature hasbetter control performance.Based on the fuzzy PID controller, we optimize parameters by particleswarm optimization. The basic principle and the algorithm flow chart of particleswarm optimization algorithm are given, and the quantization factor and scalefactor of fuzzy PID controller are optimized by PSO. After parameteroptimization algorithm, the controller results improve significantly and are better than the cascade PID controller and fuzzy adaptive PID controller. Simulationresults show that: after the particle swarm optimization, the control effect offuzzy PID controller has been significantly improved, and the optimization ofsuperheated steam temperature control has been achieved.