Crosstalk in Circular Arrays of Magnetic Sensors for Current Measurement

Circular arrays of magnetic-field sensors are of high interest in the field of power electronics for use in galvanically isolated dc current sensing. The low power consumption, high sensitivity, and mechanical flexibility of modern circular arrays of magnetic sensors for current measurement are an improvement over older closed-loop high power consumption systems. Due to their high sensitivity, such magnetic sensor arrangements are strongly influenced by magnetic fields originating not only from a targeted conductor but also from sources of interference. In this paper, we present a theoretical and experimental evaluation of the crosstalk interference in a circular array of fluxgate sensors for current measurement. We attempt to improve the modeling and the experimental setup of the state of the art method by applying a displacement in the angular position of the sensing array. Utilizing our techniques in the experimental evaluation of the rejection method, we have seen an improvement in error rejection and in turn an increased measurement accuracy of our target current source. In the best case, we have seen accuracy to within 0.02% of the current measured.