文档介绍：摘要
目前,火电厂过热汽温控制中,过热蒸汽出口温度控制要求高、可控性差,工艺上对过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。由于过热器具有大滞后、非线性、时变、多变量和有自平衡能力等特点,如何提高过热汽温的控制质量,是热工过程控制领域的重要研究课题。
本文对被控对象过热器进行了特性分析,较为详细的描述了Smith预估控制和模糊控制的系统结构及原理。论文针对过热器具有的诸多特点及火电厂对过热汽温控制的要求,提出了对火电厂过热汽温,采用Fuzzy-Smith控制的控制策略。其主要目的是使Smith预估控制和模糊控制的优势结合、互补,探索进一步提高过热汽温控制质量的有效途径。
仿真结果表明,过热汽温Fuzzy-Smith控制系统不依赖被控对象的数学模型,控制质量超过过热汽温常规PID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:过热器;汽温控制;模糊控制;Smith控制
Abstract
At present,control of steam-gas exit temperature has high requirements and bad controllability in the process of superheated steam temperature control in power are very strict requirements to the quality of superheated steam temperature control in craft work,which plays an important role in security and economy run of power to the characteristics of super-heater such as great lag,nonlinear,time-varying,multivariable and self-balance,that how to improve the control quality of superheated steam temperature has e the significant research topic in thermal process control field.
It analyzes the characteristic of super-heater which is the controlled object in the article,depicts mon paratively detailed,Smith predictive control and the system configuration and the theory fuzzy puts forward Fuzzy-Smith control strategy according to the characteristics of super-heater like great lag,nonlinear,time-varying,multivariable and the control requirements of superheated steam temperature in power main objective is to bination plementary of advantages in order to explore the effective approach to improve the control quality of superheated steam temperature.
The result of simulation indicates that super-heated steam temperature its control quality is better than superheated steam temperature cascade control system after being added into gas,steam disturbance and super-heater,the changed controlled object,which is beneficial to power plant to realize safe,economic,credibly, optimized, environment