Current sensor and its measurement method based on triaxial tunneling magnetoresistive array

Abstract

The invention provides a current sensor based on a three-axis tunnel magnetoresistive array and its measurement method, which can realize accurate current measurement of the wire to be measured when it is not perpendicular to the plane of the magnetic sensor array; the sensor includes a mounting base, and the mounting base is provided with a magnetic field detection Chip, the magnetic field detection chip adopts 4 three-axis tunnel magneto-resistive magnetic sensors; they are evenly arranged along the circumference of the installation base, that is, the three-axis tunnel magneto-resistive magnetic sensors are arranged at intervals of 90°; the magnetic field detection chip is connected to the processing circuit; the measurement method is The three-axis tunnel magneto-resistive magnetic sensor measures the magnetic induction intensity at the measuring point respectively; locates the eccentric position of the wire, that is, calculates the coordinates of the intersection point between the wire and the XOY plane; determines the inclination of the wire; calculates the average value of the current values ​​at the four measuring points, Find the current value of the wire.

Description

technical field [0001] The invention relates to the technical field of current measurement, in particular to a current sensor based on a three-axis tunnel magnetoresistive array and a measurement method thereof. Background technique [0002] With the popularity of electric vehicles, more and more charging piles appear in cities. The current sensor in the charging pile can detect abnormal conditions such as leakage and short circuit inside the charging pile in time to avoid safety accidents and ensure charging safety. At the same time, it can accurately measure the charging amount as the basis for charging. Economic functioning is very important. Since the wiring in the charging pile is in a dense and narrow space, the current sensor in the charging pile must meet the requirements of small size, and at the same time have the characteristics of AC and DC simultaneous measurement, large dynamic range, low power consumption and fast response speed. However, the current sensors...

AI Technical Summary

Problems solved by technology

However, in recent years, the research on the coreless current sensor is based on the model that the wire to be measured is perpendicular to the plane of the magnetic sensor array, such as a coreless Hall current sensor disclosed in Chinese patent CN107015047A, but it cannot be measured in the actual field. Ensure that the two are strictly perpendicular, and the current measurement error introduced when the wire is not vertical has not been eliminated so far

[0004] The technical problem to be solved by the present invention is: how to overcome the current measurement error introduced when the wire is not perpendicular to the plane of the magnetic sensor array, so that the current measurement when the wire is eccentric or inclined is more accurate

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