基于状态观测器的锅炉过热汽温反馈控制

发布时间：2018-06-26 11:44

本文选题：过热汽温 + 状态观测器　；参考：《华北电力大学》2016年硕士论文

【摘要】：在当今火电机组控制领域,过热蒸汽温度(简称过热汽温,或者主汽温)是锅炉的重要参数之一,其控制要求十分严格。但该系统具有大迟延、大惯性、参数时变等特性,并且随着装机容量的不断增大,过热器的管道也在不断加长,皆导致了热惯性和调节滞后性的大大增加,使得被控系统复杂程度和控制难度都相应增大。尤其大型机组的运行参数值与其金属材料可承受的极限值之间的余地越来越小,使得维持蒸汽参数的稳定尤为重要,是机组安全、稳定、经济运行的重要保证。大多数大型机组的汽温控制系统仍选用经典PID串级控制方式,基于输出反馈校正的原理,对于大迟延对象的调节不够及时,往往会造成很大的超调量,而且固定参数的控制器在多变的生产环境中,控制效果也不够理想。考虑到过热汽温控制对象复杂的特性,本文将两种基于观测器的状态反馈控制方案应用于过热汽温控制系统中:(1)带有误差积分反馈的观测器-状态反馈控制:针对被控对象数学模型构造不同阶次的状态观测器,并基于观测器获得的状态信息构成状态反馈控制,使被控对象的动态特性得到改善,然后引入误差的积分反馈作用,消除稳态偏差。仿真研究表明,将带有误差积分反馈的观测器-状态反馈控制方案应用到过热汽温控制系统中,具有较好的控制品质和较强的鲁棒性,且当构造观测器的阶次与被控对象阶次相等时控制效果最好。(2)基于增量式函数观测器(IFO-KΔx)的状态反馈控制:将基于增量式函数观测器的状态反馈控制与PID控制相结合,使得被控对象的大滞后特性得到了改善,同时又保留了PID控制鲁棒性强的优点。仿真研究表明:将该方案应用于过热汽温控制系统时,具有较强的抗干扰性和鲁棒性,且验证了在选择同样的观测器参数条件下,增量式函数观测器的鲁棒性要优于全维状态观测器。
[Abstract]:In the field of thermal power unit control, superheated steam temperature (or main steam temperature) is one of the important parameters of boiler, and its control requirements are very strict. However, the system has the characteristics of large delay, large inertia and time-varying parameters, and with the increasing of installed capacity, the pipeline of superheater is also lengthening, which leads to the increase of thermal inertia and adjustment lag. The complexity of the controlled system and the difficulty of control are increased accordingly. Especially, there is less and less room between the operating parameter value of large unit and the limit value of metal material, so it is very important to maintain the stability of steam parameter, which is an important guarantee for the safe, stable and economical operation of the unit. The classical pid cascade control method is still used in most steam temperature control systems of large scale generating units. Based on the principle of output feedback correction, the adjustment of large delay objects is not timely enough, which often results in a very large overshoot. Moreover, the control effect of the controller with fixed parameters is not ideal in the changeable production environment. Considering the complex characteristics of superheated steam temperature control objects, In this paper, two state feedback control schemes based on observer are applied to superheated steam temperature control system. (1) Observer with error integral feedback is used to construct different order state observer for mathematical model of controlled object. The state feedback control is formed based on the state information obtained by the observer, which improves the dynamic characteristics of the plant under control, and then introduces the integral feedback of the error to eliminate the steady-state deviation. The simulation results show that the application of observer-state feedback control scheme with error integral feedback to superheated steam temperature control system has good control quality and strong robustness. When the order of the observer is equal to the order of the controlled object, the control effect is the best. (2) the state feedback control based on the incremental function observer (IFO-K 螖 x): the state feedback control based on the incremental function observer is combined with the pid control. The large delay characteristic of the controlled object is improved, while the robustness of pid control is preserved. Simulation results show that the proposed scheme has strong anti-interference and robustness when applied to superheated steam temperature control system, and verifies that under the same observer parameters, the proposed scheme can be applied to the superheated steam temperature control system. The robustness of the incremental function observer is better than that of the full order state observer.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TP273;TM621

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