What
is Skin Effect and how does it happen?
§ According to faradays
law of electromagnetic induction, a conductor placed in a changing magnetic
field induces an emf. The effect of back emf is maximum at the centre because
of maximum lines of field there. Hence the maximum opposition of current at
inner side of conductor and minimum opposition at the surface. Hence the
current tries to follow at the surface. It is due to this reason that we take
hollow tube conductors in bus duct.
§ Taking into account
the inductance effect, its simple consider the DC current. Since its constant
& not varying hence no back emf but if we gradually start increasing the
frequency then the flux cutting the conductor goes on increasing, hence greater
the frequency greater the alternating flux cutting the conductor & hence
greater the back emf & therefore greater the skin effect.
No comments:
Post a Comment