1、三相异步电动机正反转控制线路,授课人 ：俞佳义,班级： 122电气,在实际生产中 机床工作台需要前进与后退； 起重机的吊钩需要上升与下降； 正转的控制线路能否满足这些生产机械的控制要求？为什么？,三相笼型异步电动机正反转 如何实现,将接至交流电动机的三相交流电源进线中任意两相对调，电动机就可以反转,改变电源相序,L1-U L2-V L3-W,L1-W L2-V L3-U,接触器联锁正反转控制线路,利用交流接触器，改变电源接入电动机的相序来实现电动机正反转控制。,为防止两个接触器同时得电，主电路发生短路事故在控制电路中分别串接一对对方的辅助常闭触头,接触器联锁正反转控制线路,KH,SB2,SB3
2、,SB1,KM1,KM2,KM1,KM2,KM2,KM1,联锁触头,联锁触头,当一个接触器得电动作，通过其辅助常闭触头使另一个接触器不能得电动作，接触器之间这种互相制约的作用叫做接触器联锁或互锁。,L1L2L3,FU1,FU2,KM1,KM2,KH,U,V,W,QS,如果KM1和KM2同时得电会怎么样呢,接触器联锁正反转控制线路,主电路电源短路！,熔断器熔断,L1L2L3,FU1,FU2,KM1,KM2,KH,SB2,SB3,SB1,KM1,KM2,KM1,KM2,KH,U,V,W,QS,KM2,KM1,接触器联锁正反转控制线路,如何实现电机“正转停止反转”？,低压器件动作过程如何？,按下SB
3、1, KM1线圈失电 KM1自锁触头断开,解除自锁 KM1主触头断开,电机停转 KM1联锁触头闭合，解除联锁,KM1自锁触头闭合, 自锁 KM1动合主触头闭合,电机正转 KM1联锁触头断开 对KM2联锁,合上电源开关QS,L1L2L3,FU1,FU2,KM1,KM2,KH,SB2,SB3,SB1,KM1,KM2,KM1,KM2,KH,U,V,W,QS,KM2,KM1,接触器联锁正反转控制线路,按SB2 KM1线圈得电,联锁,松开SB2 电机继续正转运行,按下SB1, KM1线圈失电 KM1自锁触头断开,解除自锁 KM1主触头断开,电机停转 KM1联锁触头闭合，解除联锁,L1L2L3,FU1,F
4、U2,KM1,KM2,KH,SB2,SB3,SB1,KM1,KM2,KM1,KM2,KH,U,V,W,QS,KM2,KM1,接触器联锁正反转控制线路,松开SB1,L1L2L3,FU1,FU2,KM1,KM2,KH,SB2,SB3,SB1,KM1,KM2,KM1,KM2,KH,U,V,W,QS,KM2,KM1,松开SB1,接触器联锁正反转控制线路,按SB3 KM2线圈得电,KM2自锁触头闭合,自锁 KM2主触头闭合,电机反转 KM2联锁触头断开 对KM1联锁,松开SB3 电机继续反转,联锁,L1L2L3,FU1,FU2,KM1,KM2,KH,SB2,SB3,SB1,KM1,KM2,KM1,KM2
5、,KH,U,V,W,QS,KM2,KM1,按下SB1, KM2线圈失电 KM2自锁触头断开,解除自锁 KM2主触头断开,电机停转 KM2联锁触头闭合，解除联锁,接触器联锁正反转控制线路,松开SB1,L1L2L3,FU1,FU2,KM1,KM2,KH,SB2,SB3,SB1,KM1,KM2,KM1,KM2,KH,U,V,W,QS,KM2,KM1,松开SB1,接触器联锁正反转控制线路,L1L2L3,FU1,FU2,KM1,KM2,KH,SB2,SB3,SB1,KM1,KM2,KM1,KM2,KH,U,V,W,QS,KM2,KM1,接触器联锁正反转控制线路,元件布置图：,QS,KM1,KM2,FR,端子排,总 结,1、三相笼型异步电机正反转实现方法,2、互锁、联锁的概念及实现方法,3、接触器正反转工作原理,THANK YOU VERY MUCH ！,本次课到此结束，感谢您的光临！,
