锅炉汽包水位模糊PID控制的研究毕业论文

大学学士学位论文-I锅炉汽包水位模糊PID控制的研究锅炉是工业过程中不可缺少的动力设备，为确保安全，稳定生产，对锅炉的自动控制十分重要，其中汽包水位是一个非常重要的被控变量。由于锅炉的水位调节过程难以建立数学模型，具有非线性、不稳定性、时滞等特点。传统的锅炉水位三冲量控制系统大都采用PID控制，其控制效果还可以进一步提高。而模糊控制不要求知道被控对象的精确数学模型，只需要操作人员的经验知识及操作数据，鲁棒性强，非常适合用于非线性、滞后系统的控制。但其静态性能不能令人满意，限制了它的应用。基于锅炉水位控制及模糊控制的特点，本文将Fuzzy-PID引入锅炉汽包水位的三冲量控制中，作了以下一些试探性工作:1)对现有的模糊PID控制器的构成方式进行归纳总结。对汽包水位的模糊PDI控制方式进行结构及性能上的分析和比较。2)提出一种采用以误差e及其积分ei作为输入语句变量，以两个一维的模糊控制器对PID参数进行在线调整的控制方式进行了探讨。仿真结果表明，控制效果有一定的提高。3)微分作用对高频干扰十分敏感，容易导致调节品质下降。锅炉本身具有一定的滞后，若不加微分作用，则控制作用的及时性无法发挥。虽然工业锅炉内扰严重，但适当的加一点微分作用对于锅炉水位的控制有一定好处。本文对采用不完全微分型模糊PID的控制情况进行仿真研究，结果表明，控制效果较为理想。关键词汽包水位模糊;PID;控制三冲量大学学士学位论文-IIBoilerWaterLevelFuzzyPIDControlofResearchAbstractBoilerisnecessarypowerplantintheprocessofindustry.Inordertoensuretheproductionandsecurity,theauto-controlofitisveryimportant.Thedrumwaterlevelisanimportantvariabletobecontrolled,itishardtogetthemathematicmodelofthewaterlevelwithadjustiveprocess.Itischaracteristicofnonlinearity,instabilityandtimelag.ThetraditionalcontrolmodeofthreevariableinthedrumwaterlevelmostlyusePID,theeffectofitcanbeimproved.Thefuzzycontroldoesnotneedprecisemathematicmodelofthecontrolledobject,itonlyneedstheexperienceofoperatorandthedataofoperating,ithasgoodrobustnessandisfittocontrolthesystemwithnonlinearityandlag.Butitsstaticcharacteristicisdissatisfactory,whichlimittheapplicationofit.Basedonthecharacteristicofwaterlevelcontrolinboilerandfuzzycontrol,thispaperdoessomeexploratoryworksasfollowsonapplyingfuzzy-controltothree-variablecontrolmodeinthedrumwaterlevel:1）Thispapersummarizesthepresentformsoffuzzy-PIDcontroller.Itanalyzesandcomparesthestructureaswellasperformanceofwaterlevelinboilercombingthecharacteristicofwaterlevelcontrolinboiler.2)Acontrolmodeisbroughtforward,whichisbasedonadjustingPIDparametersonlineviatwosingle-dimentionalfuzzycontrollerswhichuseerroranditsintegralasinputsentencevariables.Theresultofsimulationshowsthebettereffect.3)Thepartofdifferentialissensitivetohighfrequencynoise,andeasilymakethequalityofadjustdeclining.Boilerhasthecharacteristicoflag,thecontrollerisnotrapidenoughifthereisnotdifferentialitem.Althoughindustrialboilershavemanyinner-noises,itisgoodtowaterlevelcontrolthatproperlyaddsalittleofdifferentialiteminboiler.ThispaperstudiesthesimulationoffuzzyPIDcontrolwithincompletedifferentialtype,theresultofsimulationshowthattheeffectisgood.KeywordDrumwaterlevel;Fuzzy-PID;Three-variable大学学士学位论文-III-目录摘要…….......................................................................................................................IAbstract........................................................................................................................II第1章绪论................................................................................................................11.1锅炉汽包水位...................................................................................................11.2锅炉汽包水位的系统结构...............................................................................31.3汽包水位调节对象的特性...............................................................................31.3.1汽包水位在给水流量作用下的动态特性................................................41.3.2汽包水位在蒸汽流量扰动下的动态特性................................................7第2章锅炉水位PID控制系统设计.....................................................................102.1PID控制原理..................................................................................................102.2PID对控制的影响..........................................................................................112.2.1比例P调节..............................................................................................112.2.2积分I调节..............................................................................................112.2.3微分D调节.............................................................................................112.2.4PID控制器的参数整定...........................................................................122.3汽包水位调节系统的设计.............................................................................132.3.1单冲量水位调节系统..............................................................................132.3.2双冲量水位调节系统..............................................................................142.3.3三冲量水位调节系统..............................................................................162.3.4汽包水位的三冲量PID串级控制系统.................................................182.4本章小结.........................................................................................................19第3章模糊控制......................................................................................................203.1模糊控制的产生与发展.................................................................................203.2模糊控制的基本原理.....................................................................................203.2.1模糊控制系统组成..................................................................................203.2.2模糊控制器的基本结构..........................................................................213.3模糊PID控制器............................