Zero offset suppression method based on magnetized micro-asymmetric magnetic core group mirror image matching

Abstract

The invention discloses a zero offset suppression method based on magnetized micro-asymmetric magnetic core group mirror image matching, which comprises the following steps of: calculating a magnetization characteristic evaluation index IKi of each magnetic core by utilizing the characteristics of a hysteresis loop; then, calculating the magnetization characteristic evaluation index difference value between any two magnetic cores, and forming a difference value matrix Dev; obtaining a matching difficulty coefficient Di of each magnetic core according to the difference matrix Dev and an zero offset target IL; and finally, forming a magnetic modulator from two magnetic cores with similar magnetization characteristics in a large batch of magnetic cores in sequence by utilizing the difference matrix and the matching difficulty coefficients. According to the method, the matching difficulty coefficient of each magnetic core is calculated, and the magnetic core with the maximum matching difficulty coefficient is preferentially selected for matching each time, so that the matching result of a large batch of magnetic cores can be obtained in a very short time, the zero offset of the magnetic modulator can be controlled below an expected target, and a foundation is laid for improving the resolution and accuracy of the magnetic modulator.

Description

technical field [0001] The invention belongs to the field of electrical technology, and more specifically relates to a zero-point offset suppression method based on image matching of magnetized micro-asymmetric magnetic core groups. Background technique [0002] In electrical fields such as power management and on-line monitoring, the demand for non-contact measurement of weak DC currents is increasing. Taking power cables as an example, with the widespread application of cables in smart grids, the importance of on-line monitoring of cable insulation has become increasingly prominent. The insulation degradation of the cable will produce a "rectification effect", resulting in a DC leakage current in the cable, which is one of the key indicators for evaluating the insulation status of the cable. However, the DC leakage current signal is very weak, usually in the μA level, so a high-resolution non-contact DC current sensor is required. [0003] Non-contact DC current sensors ...

AI Technical Summary

Problems solved by technology

[0005] Open-loop magnetic modulators usually use a dual-core differential structure to improve measurement resolution. Currently, the resolution has reached tens of microamperes. However, it is difficult to ensure that the two cores are completely consistent, and the weak magnetization asymmetry between the cores will lead to There is a zero point offset in the magnetic modulator, which makes it difficult to further improve the measurement resolution

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