基于遗传算法的循环流化床锅炉床温模糊控制系统

模糊控制系统设计的核心问题是建立控制规则库，遗传算法是模仿自然界生物进化思想而得出的一种全局优化算法，可以用于获取模糊控制规则。然而用标准遗传算法来获取MIMO系统的控制规则库时，由于搜索空间庞大往往导致收敛速度很慢，为了克服这一缺点，该文定义了染色体中的优良模式，以此来控制遗传操作的方式和速度，加快了搜索和收敛的过程，床温是决定循环流化床锅炉安全，连续运行的重要参数，文中结合循环流化床锅炉的运行特性提出一种新的床温调节策略，采用改进后的遗传算法设计床温模糊控制器，将人工操作经验表示为染色体中的优良模式，依据经验和启发性信息来控制遗传操作的方式和速度，提高了生成模糊控制规则的效率，仿真结果表明该系统在满足负荷要求的同时，能够保证主汽压力和床温的稳定。

GENETIC-BASED FUZZY BED TEMPERATURE CONTROL SYSTEM OF CIRCULATING FLUIDIZED BED BOILER

A kernel problem in designing of fuzzy control system is generating the control rules library. Genetic algorithm is a global optimization algorithm bas ed on evolutionism. GA can be used to designing fuzzy controller, but the conver gence process usually takes a great deal of time, especially when the standard G A is used to generate the control rules of MIMO system. It is due to the huge mu ltivariable search space. To overcome this disadvantage, an improved GA is propo sed in which excellent patterns in chromosome are defined and the genetic operat ions in GA are regulated by the excellent patterns, as a result, the convergence of search process is evidently accelerated. Bed temperature, which determines the operation security and continuance of circulating fluidized bed boiler, is a very important parameter of CFB. A new re gulation strategy of bed temperature is put forward according to the working cha racters of CFB, and a fuzzy bed temperature controller is designed using the imp roved GA. In the new designing method, the genetic operations are guided with hu man experience and heuristic information. Consequently, fuzzy control rules are created with higher speed. The simulation results indicate the proposed scheme h as good efficiency. It can keep the stabilization of main steam pressure and bed temperature, at the same time meets the need of load.