Current measurement with 3-D coreless TMR sensor array for inclined conductor

Magnetic sensor arrays have been widely used in current measurement, due to their advantages of small size, low power consumption, high sensitivity, wide bandwidth, and large dynamic range. However, they all assume that the conductor is perpendicular to the plane of the sensor array and the error introduced by un-perpendicularity has not been eliminated until now. In this paper, a 3-D tunnel magnetoresistance (TMR) sensor array scheme with its correction algorithm for eccentric, inclined current-carrying conductor is proposed. The simulation comparison of the relative error caused by the inclined angle between 1-D, 2-D, and 3-D TMR sensor arrays is performed, where the maximum errors are 25%, 20.5%, and 1.39%. It is obvious that the correction algorithm of 3-D TMR sensor array can significantly improve the accuracy. Four 3-D TMR sensors are used in the experimental prototype to verify the accuracy and reliability of the correction algorithm.