Calculation method of mutual inductance coefficient of pcb planar spiral coil current transformer

Abstract

The invention provides a mutual induction coefficient calculation method of a PCB (printed circuit board) planar spiral coil current mutual inductor. A space around a primary conductor is divided into a plurality of tetrahedron units; the magnetic field intensity of four vertexes of any one tetrahedron unit is obtained; in addition, the area defined by each strand of coil of any one group of PCB plane spiral coils is used as the effective area a; the sum of magnetic flux of the same group of PCB plane spiral coils is calculated according to the magnetic field intensity H<Epsilon>; the influence of the irregular plane spiral coil, the self-outer diameter of the primary conductor and the distance between the primary conductor and the plane spiral coil on the mutual induction coefficient can be effectively avoided; the calculation precision is greatly improved; the calculation workload is reduced.

Description

technical field [0001] The invention relates to a method for calculating the mutual inductance coefficient of a current transformer, in particular to a method for calculating the mutual inductance coefficient of a PCB planar spiral coil current transformer. Background technique [0002] Current transformers are extremely important equipment in modern industry and are widely used in relay protection, current measurement, etc. Traditional current transformers have the following disadvantages: complex insulation technology requirements, flammable and explosive; magnetic saturation problems, and dynamic range Small, narrow frequency band, large error; strict requirements on the secondary side, etc., therefore, people have gradually proposed a PCB planar spiral coil current transformer (hereinafter referred to as PCB current transformer), but the existing PCB current transformer The calculation method of the mutual inductance coefficient has the following disadvantages: the calcu...

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Problems solved by technology

[0002] Current transformers are extremely important equipment in modern industry and are widely used in relay protection, current measurement, etc. Traditional current transformers have the following disadvantages: complex insulation technology requirements, flammable and explosive; magnetic saturation problems, and dynamic range Small, narrow frequency band, large error; strict requirements on the secondary side, etc., therefore, people have gradually proposed a PCB planar spiral coil current transformer (hereinafter referred to as PCB current transformer), but the existing PCB current transformer The calculation method of the mutual inductance coefficient has the following disadvantages: the calculation of the mutual inductance coefficient of the existing PCB current transformer adopts the traditional numerical calculation method, but this method is only for the square or polygonal shape of the PCB planar spiral coil. However, when the shape of the helical coil is irregular, the calculation is complicated and the workload is large, resulting in large errors in the calculation results. Moreover, when the distance between the primary conductor and the helical coil is relatively close, due to the outer diameter and shape of the primary conductor itself It will have a serious impact on the calculation of the mutual inductance coefficient, which further affects the calculation result of the mutual inductance coefficient

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