课题七 多速异步电动机的控制线路,三相异步电动机的转速公式 可知，改 变异步电动机转速可通过三种方法来实现： 一是改变电源频率f1； 二是改变转差率s； 三是改变磁极对数p。 改变异步电动机的磁极对数调速称为变极调速。变极调速是通过改变定子绕组的连接方式来实现的，它是有级调速，且只适用于笼型异步电动机。,U1,U2,V2,W1,W2,W2,L1 L2 L3,U2 V2 W2,U1 V1 W1,V2,V1,U2,L1 L2 L3,U1 V1 W1,U2 V2 W2,U1,V1,W1,1.双速异步电动机定子绕组的连接,一、双速异步电动机的控制线路,L1L2L3,KH,SB1,KM1,KM2,SB2,KM1,QS,FU1,FU2,KH,KM1,KM2,KM3,SB3,KM3 KM2,KM3 KM2,KM1,KM3,U1,V1,W1,U2,V2,W2,低速,高速YY,2.按钮和接触器控制双速电动机,L1L2L3,SB1,KM1,SB2,KM1,FU1,KM1,KM2,KM3,SB3,KM3 KM2,KM3 KM2,U1,V1,W1,U2,V2,W2,合上QS 按下SB1 KM1线圈得电,KM2,QS,FU2,KM1,KM3,低速,高速YY,KH,KH,2.按钮和接触器控制双速电动机,L1L2L3,SB1,KM1,SB2,KM1,FU1,KM1,KM2,KM3,SB3,KM3 KM2,KM3 KM2,U1,V1,W1,U2,V2,W2,KM1触头动作 电动机 联接,低速启动,KM2,QS,FU2,KM1,KM3,低速,高速YY,KH,KH,2.按钮和接触器控制双速电动机,L1L2L3,SB1,KM1,SB2,KM1,FU1,KM1,KM2,KM3,SB3,KM3 KM2,KM3 KM2,U1,V1,W1,U2,V2,W2,按下SB2 KM1线圈失电KM2,KM3线圈得电 联接,低速启动,KM2,QS,FU2,KM1,KM3,低速,高速YY,KH,KH,2.按钮和接触器控制双速电动机,L1L2L3,SB1,KM1,SB2,KM1,FU1,KM1,KM2,KM3,SB3,KM3 KM2,KM3 KM2,U1,V1,W1,U2,V2,W2,KM2,KM3触头动作 电动机YY联接,电动机高速运行,KM2,QS,FU2,KM1,KM3,低速,高速YY,KH,KH,2.按钮和接触器控制双速电动机,低速,L1L2L3,SB1,KM1,SB2,KM1,FU1,KM1,KM2,KM3,SB3,KM3 KM2,KM3 KM2,U1,V1,W1,U2,V2,W2,松开SB2 电动机继续高速运行,KM2,QS,FU2,KM1,KM3,高速YY,KH,KH,2.按钮和接触器控制双速电动机,L1L2L3,KH,SB1,KM1,KM2,SB2,KM1,QS,FU1,FU2,KM1,KM2,KM3,SB3,KM3 KM2,KM1,KM3,U1,V1,W1,U2,V2,W2,低速,高速YY,3.时间继电器控制双速电动机,KT,KM1,KT,KT,KT,电路组成分析,KH,L1L2L3,SB1,KM1,KM2,SB2,KM1,QS,FU1,FU2,KM1,KM2,KM3,SB3,KM3 KM2,KM1,KM3,U1,V1,W1,U2,V2,W2,KT,KM1,合上QS 按下SB1 KM1线圈得电,KT,KT,KT,低速起动 低速运行,低速,高速YY,KH,KH,3.时间继电器控制双速电动机,L1L2L3,SB1,KM1,KM2,SB2,KM1,QS,FU1,FU2,KM1,KM2,KM3,SB3,KM3 KM2,KM1,KM3,U1,V1,W1,U2,V2,W2,KT,KM1,KM1触头动作 电动机三角形联接低速起动 松开SB1继续低速运行,KT,KT,KT,低速起动 低速运行,低速,高速YY,KH,KH,3.时间继电器控制双速电动机,L1L2L3,SB1,KM1,KM2,SB2,KM1,QS,FU1,FU2,KM1,KM2,KM3,SB3,KM3 KM2,KM1,KM3,U1,V1,W1,U2,V2,W2,KT,KM1,KT,KT,KT,停: 按下SB3 或过载,低速起动 低速运行,低速,高速YY,KH,KH,3.时间继电器控制双速电动机,L1L2L3,SB1,KM1,KM2,SB2,KM1,QS,FU1,FU2,KM1,KM2,KM3,SB3,KM3 KM2,KM1,KM3,U1,V1,W1,U2,V2,W2,KT,KM1,按下SB2 KM1线圈得电 KT线圈得电,KT,KT,KT,低速起动 高速运行,低速,高速YY,KH,KH,3.时间继电器控制双速电动机,L1L2L3,SB1,KM1,KM2,SB2,KM1,QS,FU1,FU2,KM1,KM2,KM3,SB3,KM3 KM2,KM1,KM3,U1,V1,W1,U2,V2,W2,KT,KM1,KM1，KT各触头动作电动机低速起动 松开SB2,KT,KT,KT,低速起动 高速运行,低速,高速YY,KH,KH,3.时间继电器控制双速电动机,L1L2L3,SB1,KM1,KM2,SB2,KM1,QS,FU1,FU2,KM1,KM2,KM3,SB3,KM3 KM2,KM1,KM3,U1,V1,W1,U2,V2,W2,KT,KM1,经KT整定时间 KT延时触头动作, KM1线圈断电 KM2,KM3线圈得电 动作电动机 高速运行,KT,KT,KT,低速起动 高速运行,低速,高速YY,KH,KH,3.时间继电器控制双速电动机,L1L2L3,SB1,KM1,KM2,SB2,KM1,QS,FU1,FU2,KM1,KM2,KM3,SB3,KM3 KM2,KM1,KM3,U1,V1,W1,U2,V2,W2,KT,KM1,KT,KT,KT,停: 按下SB3 或过载,低速起动 高速运行,低速,高速YY,KH,KH,3.时间继电器控制双速电动机,三速电动机定子绕组接线图,中速Y接法 高速YY接法,二、三速异步电动机的控制线路,三速电动机的两套定子绕组,低速接法,1.接触器控制三速电动机的控制线路 形低速 Y形中速 YY形高速,L1L2L3,KM1,QS,FU1,FU2,KM2,KM1,低速,Y 中速 YY 高速,KM3,KM3,KM2,KM3,KM1,KM3,KM1,KM2,SB4,KM1,KM2,SB2,SB3,SB1,U3,W1,V1,U1,V2,V4,U4,U2,W2,W4,KM4,KM4,KM4,KM2,KM3,KM4,