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EDDY CURRENT LOSSES IN TRANSFORMER WINDINGS AND CIRCUIT WIRING

EDDY CURRENT LOSSES IN TRANSFORMER WINDINGS AND CIRCUIT WIRING
By: Lloyd H.Dixon Jr.

As  switching  power  supply  operating  frequencies  increase,  eddy  current  losses  and parasitic inductances  can greatly  impair  circuit performance.  These  high  frequency  effects  are caused  by  the  magnetic  field  resulting  from current  flow  in transformer  windings  and circuit wiring.This  paper is intended  to provide  insight  into these  phenomena  so  that  improved  high  frequency. performance  can  be  achieved.  Among other  things,  it  explains  (I)  why  eddy  current losses increase so dramatically  with  more  winding  layers,  (2)  why  parallelling  thin  strips  doesn't  work,  (3)  how  passive conductors  (Faraday shields  and  C. T .windings)  have  high  losses, and  (4)  why  increasing  conductor  surface  area
will  actually  worsen  losses and  parasitic  inductance  if  the  configuration  is  not  correct.

SIMULATION OF EDDY CURRENT EFFECTS IN TRANSFORMERS
From: IEEE Org.

This paper describes the development of an electromagnetic transient model to represent the eddy current effects in transformer magnetising current. The magnetising current of a transformer is both nonlinear and frequency dependent. The frequency dependence is due to eddy currents. The most commonly used method to represent losses in a transformer model is to add a shunt resistance across one winding. In this paper we have extended a hysteresis model based on the Jiles Atherton theory of ferromagnetic hysteresis to include the effects of eddy currents. A comparison of simulation results and test results is presented in the paper.

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ANALYSIS OF EDDY-CURRENT LOSSES OVER CONDUCTIVE SUBSTRATES WITH APPLICATIONS TO MONOLITHIC INDUCTORS AND TRANSFORMERS
By: Ali M. Niknejad, Member, IEEE, and Robert G. Meyer, Fellow, IEEE

Abstract—In this paper, a closed-form integral representation for the eddy-current losses over a conductive substrate is pre-sented. The results are applicable to monolithic inductors and transformers, especially when such structures are realized over an epitaxial CMOS substrate. The technique is verified against measured results from 100 MHz to 14 GHz for spiral inductors.

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Comments

  1. Amelia AilesFebruary 8, 2023 at 7:39 PM

    Thank you for sharing this blog. Keep posting
    For more information, visit: Eddy Current Massachusetts

    ReplyDelete

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