Design method of double-magnetic-core measurement differential leakage current sensor

Abstract

The invention relates to a design method of a double-magnetic-core measurement differential leakage current sensor. The method comprises the following steps: establishing a magnetic induction intensity amplitude model of the double-magnetic-core measurement differential leakage current sensor; establishing a double-magnetic-core measurement differential leakage current sensor optimization model bytaking the intensity and the signal-to-noise ratio SNR of a detection magnetic field as optimization targets; and determining the solution of the magnetic induction intensity amplitude model of the double-magnetic-core measurement differential leakage current sensor meeting the optimization target, and further obtaining the geometric dimensions of the inner magnetic core and the outer magnetic core of the double-magnetic-core measurement differential leakage current sensor. According to the method, a single-phase winding incoming and outgoing line differential current model is established, and an analytical expression of a cable position, a double-magnetic-core size, a material parameter, a load current, a leakage current and magnetic induction intensity in a solving area is given. The method is simple and direct, and the double-magnetic-core leakage current sensor design method based on the differential measurement mode under different power equipment requirements can be provided.

Description

technical field [0001] The invention relates to the technical field of electromagnetic measurement, in particular to a design method for a dual magnetic core measurement differential leakage current sensor. Background technique [0002] The insulation reliability of large-scale power equipment in the power grid system faces the challenge of aging and failure. Therefore, a large number of sensors need to be installed to monitor its operating status in real time after it is put into operation. When the insulation of the equipment to the ground is obviously aged, a leakage current of the milliampere level will generally be generated. At present, leakage current measurement based on a differential method is a generally accepted technology with high signal-to-noise ratio and high accuracy. This technology is mainly used to measure the single-phase-to-earth insulation leakage current of power equipment, that is, to measure the differential current between the incoming cable and o...

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Problems solved by technology

[0004] There is no technical solution to provide an analytical algorithm for the magnetic field distribution in the concentric double-circular magnetic core based on the differential measurement method. There is no technical method to provide guidance for the design of leakage current sensors for different equipment. The current excitation, geometric dimensions, and magnetic core materials have not yet been established. The relationship between the parameters and the magnetic field inside the magnetic ring

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