Electric field shield and manufacturing method thereof

Abstract

The invention relates to an electric field shield and a manufacturing method thereof. The method comprises the steps of providing plural narrow conductors to form a comb-like or grid-like electric shielding plane; and choosing a point on each narrow conductor, electrically connecting the points and connecting the points to the needed points on the circuit by outgoing lines. The shield can effectively shield the electric fields of the magnetic elements, without bringing eddy current caused by the high-frequency alternating current magnetic fields on an electric shielding conductor and the losscaused by the eddy current and without changing distribution of the high-frequency magnetic fields inside and around the magnetic elements and the magnetic parameters of the magnetic elements.

Description

technical field [0001] The invention relates to the field of electric field shielding technology, and is especially suitable for applications where there is a high-frequency AC magnetic field on a magnetic element and electric field shielding is required. Background technique [0002] Electromagnetic Conduction Emission (Electromagnetic Conduction Emission) is one of the important indicators for various electrical equipment, especially power electronic power converters to meet electromagnetic compatibility specifications. Electromagnetic conduction emission is divided into differential mode and common mode emission. The electromagnetic noise emitted by common mode conduction is mainly caused by the formation of induced charges through the distributed capacitance between conductors or devices with potential change parts in the circuit or between ground conductors with zero potential. The common-mode conduction emission conduction path is complicated, and it is the most diffi...

AI Technical Summary

Problems solved by technology

At the same time, because there are AC high-frequency magnetic fields in electrical equipment, such as magnetic components in power electronic power converters, such as magnetic fields in inductors, transformers, etc., in order to reduce the electromagnetic induction eddy current loss generated by high-frequency magnetic fields in shielded conductors, Generally, very thin copper foil is used. Since the magnetic field inside the transformer is generally parallel to the thin plane of the electric shielding copper foil, the use of thin copper foil can effectively reduce the eddy current loss caused by the AC magnetic field in the copper foil, but at high frequency (hundreds of kilohertz), it will still cause a certain eddy current loss in the shielded copper foil, which will cause heat generation and a decrease in efficiency

However, in many cases, the magnetic field in electrical equipment is not all parallel to the plane of the electric shielding copper foil, and the use of electric shielding copper foil will cause a large eddy current loss

At the same time, due to the electromagnetic induction eddy current effect of copper foil at high frequency, it will change the original magnetic field distribution characteristics, resulting in changes in the magnetic parameters of electromagnetic components and affecting performance

[0004] Therefore, the existing technology uses copper foil conductors as electric field shielding conductors, and there are two problems. One is that it will bring additional high-frequency eddy current loss under the action of an AC magnetic field, causing loss and heat, and the other is that there will be no copper foil shielding. There are changes in the magnetic field and changes in the parameters of the electromagnetic components

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