涡流产生的原因
Causes of eddy current
涡流产生示意图
Schematic diagram of eddy current production
从前面我们所学的课程可以得知，通过线圈回路的磁通量发生变化，线圈中就会产生感应电动势，回路中也就产生感应电流（穿过线圈的磁通发生变化而产生的感应电动势）。JFE电机引接线涡流产生的原因
From the courses we learned before, we can learn that the induction electromotive force is generated in the coil by changing the magnetic flux in the coil loop, and the induced electromotive force in the loop (the induced electromotive force generated by the flux change through the coil) is also generated.
如果把一块导体放在变化着的磁场中或相对于磁场运动时，由于导体内部都可构成闭合回路，穿过回路的磁通发生变化，因此在导体中也会产生感应电流，这些电流在导体内自行闭合成旋涡状，故称涡电流，简称涡流。
If a piece of conductor on the changing magnetic field or magnetic field relative to the movement, because the internal conductor can form a closed loop flux through the circuit changes, thus inducing a current in a conductor, the current in the conductor itself closed into a spiral shape, so that the eddy current, referred to as the eddy current.
涡流效应的利弊
The advantages and disadvantages of the eddy current effect
涡流效应
Eddy current effect
如右图（a）所示，由于导体电阻很小，因此涡流一般都很大。由于电流的热效应，涡流会使导体发热，消耗能量，所以涡流有时是有害的。例如通过变压器、电动机和发电机中的交变电流磁场，会使铁心产生涡流，涡流是铁芯发热，这样就造成损耗（俗称铁损）并使设备产生热量，温度升高，绝缘材料容易老化，缩短变压器、电动机和发电机的使用寿命，甚至使他们损坏。
JFE电机引接线涡流产生的原因As shown by the right figure (a), the eddy current is generally very large because the resistance of the conductor is very small. Due to the thermal effect of the current, the eddy current causes the conductor to heat up and consume energy, so the eddy current is sometimes harmful. For example, the alternating current magnetic field transformer, electric motors and generators in the core will produce eddy current and eddy current is the core heat, thus causing loss (commonly known as the iron loss) and the equipment to produce heat, temperature, material easy to aging insulation, transformer, electric machine and shorten the service life of the generator, and even make them damaged.
涡流在各种电机、变压器中是有害的，但也有可用之处，例如工厂冶炼合金时常常用的高频感应炉就是利用金属导体块中产生的涡流来熔化金属。
Eddy current is harmful to all kinds of motors and transformers, but there are also some advantages. For example, the high-frequency induction furnace often used for smelting alloys is melting metal by eddy current generated by metal conductor blocks.
电工测量仪表要求指针的摆动很快停下来，以便迅速读出读数（如电流表、电压表等）。为达到此目的，电流表的线圈要绕在铝框上，当被测电流通过线圈时，线圈带动指针和铝框一起转动，铝框在磁场中转动时产生涡流，磁场对这个涡流的作用力阻碍她们的摆动，于是指针很快地稳定指到读书位置上，这便是涡流效应的应用——电磁阻尼作用。电气阻尼作用还常用于电气机车的电磁制动器中。JFE电机引接线涡流产生的原因
Electrical measurement instruments require the swing of the pointer to stop quickly so that reading readings (such as an ammeter, a voltmeter, etc.) can be read out quickly. For this purpose, the coil current table to around the aluminum frame, when the measured current through the coil, the coil drives the pointer and the aluminum frame rotates, aluminum frame, eddy current rotating in a magnetic field, the magnetic field of the vortex force hinder their swing, so the pointer quickly refers to the stable reading position this is, the effect of the damping effect of eddy current electromagnetic applications. Electrical damping is often used in electromagnetic brakes of electric locomotives.
