【作者】 张小娟；

【导师】 马炫；

【作者基本信息】 西安理工大学 ， 控制理论与控制工程， 2008， 硕士

【摘要】 除氧器是将溶解在水中的有害气体尤其是水中的溶解氧从水中除去,以免这些有害气体进入锅炉系统造成热力设备腐蚀,从而影响锅炉系统的正常运作,所以除氧器在热力发电厂中起到了很重要的作用。除氧系统具有滞后、时变、非线性等特点,对此常规PID控制器无法获得满意的效果,为了保证除氧器能达到很好的除氧效果,就需要采用先进的控制方法。很多学者研究了如何对除氧器的压力、水位进行控制,本论文以除氧器为被控对象,分析了PID控制和模糊控制的优缺点,将PID控制和模糊控制的优点结合起来,采用模糊规则在线整定PID的k_p、k_i、k_d三个参数的模糊PID技术设计了除氧器的温度控制系统。文中以模糊PID控制算法为基础,设计了以AT89S51单片机作为核心的嵌入式系统,并配有键盘和显示组成小型操作系统,并介绍了硬件电路设计和软件程序设计,针对嵌入式系统的硬件和软件方面介绍了一些工程上实用的抗干扰措施。文中使用MATLAB软件对PID控制、模糊PID控制分别进行了仿真研究,仿真结果表明参数模糊PID控制能满足调节时间短、超调量小且稳态误差在104±3℃内的控制要求；在实验室条件下,模拟现场环境,对系统进行了软件的调试及实验仿真。实验结果表明,系统能够达到预期的指标。更多还原

【Abstract】 Deaerator plays an important role in thermodynamic power plants because it can remove the harmful gas, especially oxygen in water. Deaerator system has the characteristic of delay, non-linearization and time-variable, thus normal PID can not achieve desired effect. In order to accomplish the good effect, people design the auto control system of deaerator which based on the advanced control method. Many researchers give the control strategies based on pressure and water level of deaerator system. It is designed based on control PID theory, which involves fuzzy control rules, is employed to make real-time adjustments to the three parameters kp,kj and kd of the PID of the temperature of deaerator here.Accordingly, the embed system with the core of AT89S51 is designed on the base of fuzzy PID controlling arithmetic. What’s more, a small system with keyboard input and Light Emitting Diode is designed for the system which has the function of signal collecting, data displaying, keyboard controlling, data computing. The design of the hardware and software are described in detail. And some practical hardware and software reliability measures of embedded system are introduced. First, simulations of PID control and fuzzy PID control concerning their respective control quality are done by MATLAB 6.5. Moreover, the simulation results show that its robustness is good, because effective control makes the regulating time short, the overshoot and the steady-error very little. At the same time, used AT89S51 debugging system to carry out an experiment on control system.更多还原