火电超临界机组鲁棒控制器设计与降阶

发布时间：2018-02-26 16:17

  本文关键词： 超临界机组 协调控制系统 鲁棒控制 LMI 系统辨识 控制器降阶 协调-主汽温联合控制　出处：《浙江大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着超临界火力发电机组逐渐成为我国火电领域的重要发展方向,对其控制的要求也不断提高,然而机组具有较高的温度与压力,并且伴随着非线性、强耦合等复杂特点,因此需要不断深入对超临界协调控制系统的研究。本文在总结了协调控制方案已有成果的基础上,完成了超临界机组鲁棒控制器设计及控制器降阶方法的研究,并提出了协调控制与主汽温的联合控制方案。其主要研究成果为:1)使用鲁棒控制作为理论框架,设计了适用于超临界协调控制系统的多变量鲁棒控制器:按照系统定值跟踪的控制目标,引入期望闭环响应矩阵与输出加权滤波器,构建了系统的广义对象,并基于线性矩阵不等式(Linear Matrix Inequality,LMI)方法求解该对象的鲁棒控制问题,获取满足闭环系统H∞范数最小的控制器,确保系统符合鲁棒稳定性条件。通过与模型预测控制的仿真对比,验证了此方法的优越性,能满足电厂复杂的控制需求。2)由于高阶控制器在分布式控制系统(Distributed Control System,DCS)中实现困难,给出了基于系统辨识理论的控制器降阶方法:将高阶控制器作为待辨识模型,采用广义二进制噪声(Generalized Binary Noise,GBN)信号开环激励控制器,获取辨识实验中控制器的输入输出数据,在满足辨识相对误差较小的前提下,选择低阶模型进行辨识。此外针对PID控制器在实际电厂的普及,提出了低阶模型转换为PI以及基于离散PID结构的参数辨识方法,仿真结果表明,辨识结果令人满意,并且能基本保留降阶前的控制品质,为电厂PID的结构与参数整定带来了全新的思路。3)通过对超临界机组主汽温的特性及现有控制方法的分析,提出了协调-主汽温联合控制系统:引入与主汽温存在耦合关系的物理量,该变量与协调控制系统相关,因此构建联合控制系统,充分考虑对主汽温产生影响的因素来实现对其更全面的控制。之后,采用鲁棒控制及降阶框架对该系统设计控制器,通过仿真验证了该控制系统优于传统方法,减少耦合变量对主汽温干扰的同时,保证对其控制的快速与稳定。
[Abstract]:With the supercritical thermal power generating set gradually becoming an important direction of development in the field of thermal power in China, the requirements for its control are also increasing. However, the unit has a higher temperature and pressure, and accompanied by nonlinear, strong coupling and other complex characteristics. Therefore, it is necessary to study the supercritical coordinated control system deeply. On the basis of summarizing the existing achievements of the coordinated control scheme, the design of the robust controller for the supercritical unit and the method of reducing the order of the controller are studied in this paper. A joint control scheme of coordinated control and main steam temperature is proposed. The main research result is: 1) robust control is used as the theoretical framework. A multivariable robust controller suitable for supercritical coordinated control system is designed. According to the control target of constant value tracking of the system, the expected closed-loop response matrix and the output weighted filter are introduced to construct the generalized object of the system. Based on the linear matrix inequality (LMI) method, the robust control problem of the object is solved, and the controller satisfying the minimum H 鈭，

本文编号：1538744