【作者】 席学军；

【导师】 姜学智；

【作者基本信息】 清华大学 ， 动力工程及工程热物理， 2004， 硕士

【摘要】 循环流化床锅炉(Circulating Fluidized Bed Boiler, CFBB)燃烧系统具有非线性、多变量耦合、参数时变以及大惯性、大延迟等特点,使其自动控制的实现非常困难。本文采用自抗扰控制策略 (Auto Disturbance Rejection Control, ADRC),为这一问题的解决提供了新的思路。ADRC具有不依赖于对象精确数学模型以及较好的抗干扰性、解耦性、鲁棒性,因此本文的部分内容围绕纯滞后对象的ADRC策略展开。研究和探讨适于类似于循环流化床锅炉燃烧系统特点的ADRC结构改进与参数整定方法是论文的主要工作。首先,深入研究了循环流化床锅炉的结构和工艺流程,在此基础上总结CFBB系统各个部分的数学模型,以及基本控制量。前人对CFBB为对象的动态建模仿真实验和理论研究,为ADRC应用于循环流化床燃烧系统提供了保证。然后,详细讨论了ADRC控制器的结构形式和算法实现,结合典型一阶二阶大惯性纯时滞系统对参数整定以及ADRC的结构进行了改进,并引入时间尺度的方法,简化同类对象的ADRC的参数整定。在此基础上,通过球磨机的实例,与原型ADRC的方法进行比较,仿真结果表明该控制策略优于原型ADRC,能有效应用于非线性时变纯滞后系统,即使在模型不确定、存在外部扰动和测量噪声的情况下,也能表现出良好的动态性能。最后,以CFBB炉燃烧系统为对象,研究ADRC在复杂热力系统中的应用。控制系统的设计以CFBB燃烧系统数学模型,以及相对增益矩阵解耦分析为基础。设计基于解耦矩阵的ADRC结构以及ADRC控制器参数,并与传统PID控制以及先进神经网络自适应跟踪策略进行对比。研究结果表明,在模型不确定、变工况和变量强耦合情况下,ADRC控制具有更好的解耦控制性能、抗干扰性以及鲁棒性。更多还原

【Abstract】 Characterized by nonlinearity, multivariable coupling, time variation of parameters and large inertia, large time delay, circulating fluidized bed boiler (CFBB) combustion system face a hard work in the control implements. In this thesis, auto disturbance rejection control (ADRC) is proposed to solve the difficulties in this field. ADRC is concerned the advantage of independence on mathematical models, decoupling, adaptive and robust in rejecting. The main task of the thesis is to study and develop parameters tuning and control approaches applied to the characters of circulating fluidized bed boiler combustion system using ADRC. First, deep study of the structure of circulating fluidized bed boiler and technical flow and summarize all kinds of CFBB mathematic models. Predigesting the progress of CFBB combustion system model is thoroughly investigated and a viable control parameter and algorithm of models is developed for practical uses. The theoretical analyses and simulation experiments, set for CFBB nonlinear dynamical systems, guarantee the engineering applications of ADRC.Second, the structure and algorithm of ADRC controller is discussed in detail and modified the structure and parameters tuning of the ADRC applied to the typical large inertia and large time delay characters of first order and second order plants. Time scale was introduced to tune parameters and simplify the ADRC controller of plants in same type. So comparing the new type ADRC to the old one on example of the ball mill system, the result of numerical simulation was presented that new type ADRC is better than the old one applied to the large inertia and large time delay plants with good dynamic performance.Finally, applications of ADRC controller in a practical thermal system are studied in the combustion system of circulating fluidized bed boilers. The control system is based on the CFBB combustion mathematic model and <WP=5>decoupling analysis with related gain matrix, design the structure of ADRC with decoupling matrix and the control parameters of ADRC. Comparing to the traditional PID control and advanced PID neural-network adaptive-tracing control, the study results demonstrate that the ADRC possesses better decoupling control qualities,adaptive adaptive and robust in rejecting in rejecting under time variation of parameters,model uncertainties and strong multivariable couplings.更多还原