【作者】 刘斌；

【导师】 刘丁；

【作者基本信息】 西安理工大学 ， 电气工程， 2002， 硕士

【摘要】 本文研究了新型DCS在燃气／蒸汽联合循环电厂的应用方案。 文中首先综述了目前国内外DCS的发展概况和趋势，分析了目前分散控制系统(DCS)的缺陷，并着重分析了DCS在火电厂监控系统中的应用情况，提出了采用基于现场总线技术的现场总线控制系统(FCS)实现DCS控制的设计方法。并把这一控制方法用于杨凌电厂DCS控制系统中，针对现有具体情况提出了详细方案设计。 火电单元机组由锅炉、汽轮机、发电机、电网和负载等设备组成，是一个具有不确定性的复杂多变量受控对象，要建立其精确的数学模型是非常困难的。采用常规控制方法设计的协调控制系统，其参数是在一定的工况下经人工试凑得到的，当系统工况发生变化时，控制品质变差甚至会导致机组不能正常工作。针对这一问题，本课题中提出基于神经网络解耦控制方法，并针对单元机组的负荷控制进行了系统设计和仿真研究，验证了该方法的可行性。 此外，在杨凌电厂DCS控制系统中通讯设备种类较多，各类设备的通讯协议／规约不同(主要有RS232、RS485、MODBUS、PROFIBUS-DP以及OPC 摘要 技术），造成不同控制系统间的通讯存在一定的囚难，导致机组的整体监控数据 不全，存在协调性的问题。冈此在保证处理好控制性能的同时，解诀好系统间 的通讯问题娃整个设计方案的关键一环，为此本课题中对该系统中的通讯硬／ 软什设计进行了详细分析，并提出了可靠合理的通讯设计方案，以降低系统的 造价，并有利丁提高系统的囱动化水平。更多还原

【Abstract】 In this thesis applications of novel-type DCS in fuel gas/steam-combined circular power plants are studied and discussed.First the development and the trend of DCS are overviewed to analyze the existing defects of DCS and to emphatically discuss its applications in monitoring control systems of thermal power stations as well. In the thesis a method to implement DCS control is formulated based on PCS in field bus technique and applied into DCS control systems of Yang Ling Power Station. Meanwhile, aiming at the practical situations a detailed project design is presented.The thermal power unit plant, which is a complex multivariable controlled system with uncertainty, is composed of boilers, steam turbines, dynamos, power networks, loads and such other equipment. Therefore, it is very difficult to accurately construct its mathematical model. For coordinated control system designed using general control methods, the parameters are made up artificially in certain operating situations. When the situation changes, control performance will change for worse or even lead to abnormal operation of the unit. A decouplingcontrol method based on neural networks is formulated for the problem and aiming the problem of load control over the unit plant, system design and simulations are made to verify the feasibility of the method.Moreover, in DCS of Yang Ling Power Station, various communication equipment as well as the different communication protocols / agreements for varied equipment (mainly including RS232, RS485, MODBUS, PROF1BUS-DP and OPC technique) lead to considerable difficulty in communicating among diverse control system, incomplete overall monitoring data of the unit plant and incoordination. Therefore, communication among control systems is the key problem of the whole design while ensuring good control performance. Therefore communication hardware / software designs in the systems are discussed in detail and reasonable communication design scheme is presented in the project so as to reduce system cost and help increase system automation level.更多还原