陕西工业职业技术学院基于PLC的变频器多段速调速系统设计专业:机电一体化班级:机电1105班姓名:冯志超指导教师:司老师1陕西工业职业技术学院目录1绪论...............................................................................................................................................12课题的背景...................................................................................................................................1背景分析..........................................................................................................................................23PLC和变频器的介绍...................................................................................................................54PLC的结构及特点.......................................................................................................................55PLC的工作原理...........................................................................................................................76PLC的应用...................................................................................................................................77PLC发展趋势...............................................................................................................................88PLC控制变频器带电机多段速运行...........................................................................................89变频器的介绍................................................................................................................................810变频器的控制方式......................................................................................................................911变频器的应用..............................................................................................................................912PLC与变频器的组合...............................................................................................................1013变频器和PLC进行配合时所需注意的事项...........................................................................1014变频调速系统............................................................................................................................1115变频调速的基本控制方式........................................................................................................1116系统的控制要求........................................................................................................................1217方案的确定................................................................................................................................1218S7-200PLC.................................................................................................................................219MicroMaster420变频器.............................................................................................................1320外部电路设计............................................................................................................................1421变频开环调速...........................................................................................................................1422.按项目控制要求设计PLC和变频器....................................................................................1523PLC程序设计...........................................