【作者】 张新颖；

【导师】 金慰刚；

【作者基本信息】 华北电力大学（北京） ， 控制理论与控制工程， 2007， 硕士

【摘要】 随着控制技术的不断发展,生产过程自动化程度不断提高,工业过程中采用的自动控制回路也就越来越多。这些控制回路大多在运行初期具有良好的性能,在运行一段时间后,由于受到各种变动因素的影响,控制回路性能将会变差。目前的过程控制中普遍采用DCS系统,很容易从中得到大量的过程运行数据,如何有效利用这些数据分析控制回路的性能就成为很有价值研究课题。本文首先介绍了当前控制系统性能评价和诊断各种不同的方法以及工业应用情况。接着,着重介绍了基于最小方差的控制系统性能评价方法,并对某电厂除氧器水位控制系统进行了性能评价研究,结果表明,这种性能评价方法对实际控制回路性能的监测具有重要的指导意义。最后,本文针对串级控制系统提出了一种基于输出最小方差性能的控制系统故障诊断方法,并对火电厂过热汽温系统进行了仿真研究,结果表明,这种诊断方法可以准确有效的诊断出串级控制系统故障的来源。更多还原

【Abstract】 With the development of control theory and technology, more and more control loops are applied in the process industry. These controllers always can achieve good performance at the beginning, but it will become worse some time later because some factors have been changed. Now it is easy to obtain large amount of data due to widely used DCSs. It is necessary to assess the control performance from these data. Firstly, in this paper, the different methods of control performance assessment and industrial application are introduced. Secondly, the methods of control performance assessment based on the minimum variance control are emphasized. The simulation of the power plant deaerator level control system shows that it is very useful method to monitor the condition of the control loops. Finally, based on the minimum variance of the control output, a fault diagnosis of cascade control systems is introduced. A new scheme to assess the performance of a superheated steam temperature control system is proposed. The simulation results demonstrate that the fault can be diagnosed exactly.更多还原