Fluxgate current sensor and current measuring method

Abstract

The invention provides a fluxgate current sensor and a current measurement method, and the fluxgate current sensor comprises an auxiliary magnetic core and at least two closed-loop magnetic circuits. The closed-loop magnetic circuits are symmetrically coupled; and the auxiliary magnetic core is arranged at the coupling joint of the closed-loop magnetic circuit. The fluxgate current sensor is provided with a symmetrically coupled closed-loop magnetic circuit, a magnetic field environment for symmetrical measurement can be provided, the influence of higher harmonics caused by the position of an eccentric conductor is reduced, the production error between different sensors is reduced, and the measurement precision is improved.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and in particular relates to a fluxgate current sensor and a current measurement method. Background technique [0002] The current sensor based on the fluxgate principle is a magnetic field sensing device that is affected by an external magnetic field, an auxiliary driving magnetic field generated by an alternating current, and a compensation magnetic field generated by a feedback current, and can generate an excitation signal for obtaining external magnetic field information. The positive and negative directions are symmetrical when the excitation signal is only driven by the auxiliary alternating current. Under the action of an external magnetic field, the asymmetry of the excitation signal is related to the magnitude and direction of the external magnetic field, and the vector information of the external magnetic field is fed back and read after the compensation magnetic field is use...

AI Technical Summary

Problems solved by technology

[0003] Some known fluxgate current sensors have a magnetic field detection device surrounding the current conductor to be measured, for a ring or other closed or nearly closed shape around the current conductor to be measured, there is a possibility of proximity to the conductor side due to differences in conductor position and eccentricity And the uneven distribution of the magnetic induction intensity of the magnetically permeable material away from the conductor side, which in turn affects the measurement accuracy of the sensor

[0004] In particular, small currents generate weak magnetic fields and are susceptible to external magnetic fields

Therefore, the accuracy of current sensors used to detect small currents or small differential currents is generally low

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