目 录
1 绪论 ...............................................................................................................................................................1
1.1 变频器恒压供水产生的背景和意义 ............................................................................................1
1.2 变频恒压供水系统理论分析 ...........................................................................................................1
1.2.1 变频恒压供水系统节能原理 ...............................................................................................1
1.2.2 变频恒压控制理论模型 ......................................................................................................2
1.3 恒压供水控制系统构成 ...................................................................................................................3
2 变频恒压供水系统设计 ............................................................................................................................4
2.1 设计任务及要求 ..............................................................................................................................4
2.2 系统主电路设计 ............................................................................................................................5
2.3 系统工作过程 ................................................................................................................................6
3 器件的选型及介绍 ....................................................................................................................................7
3.1 变频器简介 ....................................................................................................................................7
3.1.1 变频器的基本结构与分类 ................................................................................................7
3.1.2 变频器的控制方式 ............................................................................................................7
3.2 变频器选型 ....................................................................................................................................8
3.2.1 变频器的控制方式 ............................................................................................................8
3.2.2 变频器容量的选择 ............................................................................................................9
3.2.3 变频器主电路外围设备选择 ..........................................................................................11
3.3 可编程控制器(PLC) ....................................................................................................................13
3.3.2 PLC 的工作原理 ...............................................................................................................14
3.3.3 PLC 及压力传感器的选择 ...............................................................................................14
4 PLC 编程及变频器参数设置 ...................................................................................................................15
4.1 PLC 的 I/O 接线图 .........................................................................................................................15
4.2 PLC 程序 .......................................................................................................................................15
5.系统安装 ....................................................................................................................................................19
5.1 PLC 安装位置确定 .........................................................................................................................19
5.2 变频器的安装 ................................................................................................................................19
5.2.1 变频器的安装环境 ............................................................................................................19
5.2.2 安装方式 ............................................................................................................................19
5.3 变频器和电机的距离确定电缆和布线方法 ................................................................................20
5.4 系统安装图 .....................................................................................................................................20
6.设计预期与结果分析 ................................................................................................................................21
6.1 设计预期 .........................................................................................................................................21
6.2 结果分析 .........................................................................................................................................21
参考文献 ........................................................................................................................................................22
致谢 ................................................................................................................................................................23
附录 ................................................................................................................................................................24
