自动化专业毕业设计-基于Fuzzy-PID控制的火电厂再热器温度控制系统设计.doc

摘 要 目前，火电厂热汽温控制中，热蒸汽出口温度控制要求高、可控性差，工艺上对热汽温控制的质量有非常严格的要求在火电厂安全性和经济性运行中有着重要的作用。由于热器具有大、非线性、时变、多变量和有自平衡能力等特点，如何提高热汽温的控制，是热工过程控制领域的重要研究课题。 本文对被控对象热器进行了特性分析，较为详细的描述了控制和模糊控制的系统结构及原理。论文针对热器具有特点及火电厂对热汽温控制的要求，提出了对火电厂热汽温采用Fuzzy-的控制策略。其主要目的是使控制和模糊控制的优势结合、互补，探索进一步提高热汽温控制质量的有效途径。 仿真结果表明，热汽温Fuzzy-控制系统不依赖被控对象的数学模型，控制热汽温常规控制系统，这有利于火电厂实现安全、经济、可靠、优化和环保的要求，具有广阔的应用前景。 关键词：控制控制模糊控制Abstract At present, the control of steam-gas exit temperature has high requirements and bad controllability in the process of reheated steam temperature control in power plant. There are very strict requirements to the quality of reheated steam temperature control. The relatively stable of reheated steam temperature plays an important role in security and economy running of power plant. Due to the characteristics of re-heater such as large inertia, nonlinear, time-varying, multivariable and self-balance, that makes how to improve the control quality of reheated steam temperature has become the significant research topic in thermal process control field. ?In this paper, it analyses the characteristic of reheater which is the controlled object, describes the configuration and the theory in common use of PID control and fuzzy control system comparatively detailed. Paper puts forward Fuzzy-PID control according to the characteristics of reheater like large inertia, nonlinear, time-varying, multivariable and the control requirements of reheated steam temperature in power plant. Its main objective is to make combination and complementary of advantages of PID control and fuzzy control in order to explore the effective approach to improve the control quality of reheated steam temperature. The result of simulation indicates that the Fuzzy-PID reheat steam temperature control system does not rely on mathematical models of controlled objects, and that the quality of Fuzzy-PID control system is better than conventional PID system. This control strategy is beneficial to realize safe, economic, credibly,