Chapter two DC Tachogenerator 2.1 直流电机基本结构和工作原理saw1
(The Basic Structure and Operation Principle of a DC Machine)
直流发电机工作原理
直流电动机工作原理
2.2 直流电机的电势和电磁转矩(EMF and MMF of DC machine )
电势:n a pN n C E e a φφ60=
= 电磁转矩:a a T I a
空气净化风扇pN I C T φπφ2== 磁场分布和电刷电势
图2 - 13 直流电机磁路图2 - 14 气隙中磁通密度分布图
图 2 - 2 磁场分布和电刷电势糠硫醇
2.3 直流测速发电机(DC Tachogenerator)
PRINCIPLE OF OPERATION :
The DC Tachogenerator is a speed transducer, which develops DC voltage proportional to speed of the motor connected to it. Permanent Magnetic field eliminates the need of external excitation and offers extremely reliable and stable outputs. The accuracy of the tachogenerator decides the maximum accuracy of speed of the controlled machine. They are widely used for feedback and display purposes. 直流测速发电机及其输出特性 1) 对直流测速发电机要求:
(1)输出电压与转子转速之间的关系(称为输出特性)应为线形,如图2-17;
图2-17 测速发电机的理想输出特性
干手器(2)输出特性的斜率要大;
乙醇汽油添加剂
(3)温度变化对输出特性的影响要小;
(4)输出电压的纹波要小;
(5)正、反转两个方向的输出特性要一致。
2)输出特性
图2-18 直流测速发电机接上负载
a a a a R I E U -=
L毛辊清洗机
a a R U I = a L a a a R R U E U -
=