Detailed study on error characteristics of core-less hall-effect current transducer

摘要

A critical study on the error characteristics of the core-less Hall-Effect current transducer is presented in this paper. Current transducer that is formed using Hall-Effect sensing elements arranged in the form of a circular array, around the current carrying conductor, has been reported in the literature. This scheme has many benefits as no magnetic core is used, but the accuracy of the system depends on various factors, including the positioning of the conductor at the center of the circular array and positioning of the individual Hall sensing elements. Positioning includes the alignment of the axis of sensitivity of the Hall sensor to the tangential component of the field and the position of the sensor in the predefined circle. When the sensor unit is made, there will be misalignments for each Hall sensor from its predefined position and direction of sensitivity. In addition, any deviation of the sensors array from the circular shape, say an oval shape, will introduce errors. Also, the normal of the plane of circular array should be parallel to the axis of the conductor. This may not be the case in practice. In order to analyze the effect of the above mentioned parameters and to quantify the error due to each in the final output, a suitable prototype of the Hall Effect current transducer has been developed and the above listed parameters have been tested in the laboratory, one by one. Along with the experimental studies, ANSYS Maxwell tool has been used for conducting the Finite Element Method (FEM) analysis and to support the experimental observations. This study will help the sensor designer to get detailed insights into the effect of various misalignments in the output.