Interference rejection algorithm for current measurement using magnetic sensor arrays

Solid state magnetic sensors can measure a current by sensing the field nea r the conductor. Means are required to distinguish between useful and inter ference fields and that are those of conductors near the current under meas urement and environmental fields. Starting from analytical expressions of the magnetic field, spatial harmoni c analysis is performed. It is then possible to separate the effects of the field generated by the current under measurement from those of interferenc e fields. A new algorithm based on spatial Discrete Fourier Transform (DFT) capable o f calculating the current to be measured is presented. The algorithm can be implemented by a DSP that processes output signals of solid state magnetic sensors forming a circular array centred in the current conductor. (C) 200 0 Elsevier Science S.A. All rights reserved.