【作者】 唐义军；

【导师】 徐治皋；

【作者基本信息】 东南大学 ， 动力机械及工程， 2004， 硕士

【摘要】 目前,国内绝大多数300MW以上大型火电机组都采用了DCS 集散控制系统,使电站自动化应用水平得到了提高,使许多新型高级控制算法的实现成为可能,这些算法在理论上已被证明优于传统的PID控制算法。由于DCS已从一个高科技产品变为一种传统工业品,加上市场的激烈竞争,为了降低成本,制造厂大多不再投入大量的力量来从事应用开发研究,DCS中实现的控制策略大多仍是传统的、经典的控制策略,另外PID控制器本身不需要精确的数学模型,PID控制参数的物理关系明确,容易在线整定,主客观两方面的原因,导致在热工控制领域占主导地位的控制器还是PID控制器,限制了先进控制手段在现场广泛应用。本文利用现有的DCS控制系统平台,开展了先进控制策略研究和工程实用化研究,解决了工程上汽温较难控制的应用问题。针对嘉兴发电有限责任公司一期工程2(300MW机组同时存在的过热汽温、再热汽温品质差,易超温问题,用新的控制理念―状态向量控制,对原汽温控制系统进行了重新设计,纠正了原控制回路存在的缺点,详细介绍了各向量回路模型功能:汽温预测功能模型,Ⅱ级减温器进口温度动态控制值模型,Ⅰ、Ⅱ级减温调节器调节任务分配、转移模型,等等。并对如何控制策略提高机组的经济性的途径作了剖析-自动改变主汽温的控制设定值从540℃提高到542℃,取得了较好的工程应用效果。数年的运行结果表明,该控制策略明显好于传统控制策略。更多还原

【Abstract】 Most of domestic 300 MW and more larger thermal powers adopt DCS control system at present, which improves automatic level of plant powers, and makes it possible that many new advanced control strategies could apply in control fields. It theoretically proves that advanced control strategies obviously superior to conventional control strategy in control character.DCS has been becoming conventional industry product from high-tech one, so there is severe competition in DCS price. In order to decrease cost of the products, most manufactories are reluctance to spend a plenty of energy dealing with application of exploitation research, most control strategy of DCS is conventional and classic. While PID controller doesn’t demand exact math model itself, and PID control parameters, which exists definite physics relation, are easy to be adjusted on-line. Based on the two aspect reasons of objective and subjective influences results in limitation of application of advanced control strategy in widely, so dominant controller is just the same PID controller.This thesis utilizes DCS control system platform in being running, develops research of advanced control strategy and engineering practical application, and resolves the problem which steam temperature in power plant is difficult to be controlled. Aiming at the disadvantage quality of both super-heat steam temperature and re-heat steam temperature which used to easily make the units go beyond the limitation of steam temperature operation in Jiaxing Power Generation Co. Ltd., author uses new control idea--- vector-space control, and redesign the steam-temperature control system which has been obviously correcting fault and shortage of original strategy of steam-temperature control system. This thesis also analyzes main functions of sub-modules ,which include module of steam-temperature prediction, second stage attemperator in-let temperature dynamic control, assignment and transfer of first and second stage attemperator regulation task and etc. In the new steam-temperature control system in detail, and discusses how to improve the efficiency of power plants in the application of this new <WP=6>steam-temperature control system-- automatic adjustment of main steam-temperature control value from 540℃ to 542℃. The new steam-temperature control system based on vector-space, which has been performed for several years in a certain 300MW power plant, is better than the classic control system.更多还原