摘要主蒸汽温度是现代火力发电厂机组运行过程中需要监视及控制的主要参数之一， 它直接关系到整个机组能否正常安全运行，主汽温过高，将导致汽轮机的高压缸和 过热器因为承受高温而损坏，从而直接危及机组的安全运行；主汽温过低，则会使 得机组热效率降低，从而影响机组的经济性。同时，过低的主汽温会增加蒸汽的含 水量，使得汽轮机叶片使用寿命缩短。因此，我们必须严格控制主汽温在给定值附 近，并且能保证温度不会发生剧烈变化，这样才能既保护整个机组设备的安全运行， 同时也能保证电厂的经济效益。81113

常规 PID 调节器是一种应用广泛，技术已相对成熟的控制方法。但在过程控制 领域中尤其是对于再热汽温这种复杂的控制对象，因为 PID 控制器的局限性，控制 参数难以自行调整，所以控制效果不佳。模糊控制理论能够有效方便的实现人的控 制经验和制定策略，而且对控制对象的依赖性不大，并且模糊决策具有明显的非线 性对于复杂的控制对象控制效果要更好。本文将针对火电机组过热汽温控制的特点， 选用 FUZZY-PID 复合控制和模糊自整定 PID 控制两种方案对常规 PID 串级控制系统 进行改进。并通过 MATLAB 进行仿真实验，仿真结果表明：加入了模糊控制策略的控 制器能有效实现对再热汽温等复杂对象的在线控制，并且能将快速性和稳定性统一 起来，具有较强的鲁棒性和抗干扰能力。

毕业论文关键词: 主蒸汽温度，模糊控制，串级控制，PID 自整定，仿真

Abstract The safe operation of the main steam temperature is in the running process of the modern thermal power plant unit to monitor and control one of the main parameters。 It is directly related to the entire unit can run normally and safely, the main steam temperature is higher, so that the steam turbine high pressure cylinder and a superheater and damage due to withstand high temperatures, and thus directly threaten units; main steam temperature is low, it will reduce the unit thermal efficiency, thus affecting the economy of the unit。 Therefore, we must the main steam temperature controlled strictly in the vicinity of a given value, and can ensure the temperature does not change drastically, so as to not only protect the safe operation of the whole unit equipment and ensure the benefit of the power plant。

Conventional PID regulator is a kind of widely used, technology has been relatively mature control method。 However, in the field of process control, especially for the reheating steam temperature, because of the limitation of the PID controller, the control parameters are difficult to adjust, so the control effect is not good。 Fuzzy control theory can be effective and convenient for the realization of people's control strategy and experience, the object is not dependent on, and fuzzy nonlinear for complex control object control effect is better。 In this paper, according to the characteristics of the superheated steam, the control system of the conventional PID cascade control system is improved by using FUZZY-PID composite control and fuzzy self-tuning PID control。 And through MATLAB simulation。 The simulation results show that: adding fuzzy control strategy controller to realize on-line control of reheat steam temperature of complex objects, and the rapidity and stability of unity and has strong robustness and anti-interference ability。

Key words: main steam temperature, fuzzy control, cascade control, PID auto tuning, simulation

目录

第一章 绪论 1

1。1 选题背景及意义 1

1。2 课题研究现状 2

1。2。1 火电厂主蒸汽温度控制的研究现状