A Simplified Tilt-Resilient Probe Design for Noninvasive Current Measurement Using Magnetic Sensors

This article presents a new simplified design of a noninvasive current probe that accurately measures current flowing through a conductor using magnetic sensors. The innovative design incorporates four magnetic sensors on the base of a 3-D printed current probe. A suitable interface circuit processes the output of the magnetic sensors of the probe to accurately determine the unknown current. The probe head is suitably designed to have a pointed axis of axial length $R$ to accurately place the magnetic sensors at a calibrated distance $R$ from the center of the conductor. Experimental validation was conducted on a prototype of the proposed current probe and the effect of the tilt of the probe in three-dimensional space was studied. The prototype of the current probe was designed for a range of (0–50) A. The accuracy of the designed current probe is observed to be 1.83 % when measuring a current range of (0–15) A and 0.93 % for a current range of (16–50) A. The proposed design ensures accurate positioning and orientation of the current probe for current measurement with fewer positional adjustments required to compensate for the effect of tilt compared to previous topology.

I. Introduction

The significance of non-invasive current measurement meth-ods is on the rise, owing to their non - galvanic connections to the measurand equipment and adaptable placement [1], [2]. This approach has seen success, owing to advancements in the development of highly sensitive magnetic sensors [3] and innovative mechanical and electronic interface designs for current probes employing these sensors [4]–[7]. Several notable methods have emerged, including placing a magnetic sensor in the loop of a magnetic core around the current-carrying conductor [8], core-less designs with circular arrays of magnetic sensors [6], and non-enclosure based current probes [5], [9].