Analysis of a Zero-Flux Type Current Sensor Using a Hall Element

Various types of clamp-on current sensor have long been in use, because they are so easy to handle. Recently, power instruments such as inverters have come into wide use, and clamp-on sensors have been adopted in industry. Current sensors should offer such high-performance characteristics as a wide frequency band, wide measurement range, and high accuracy. In this study, we used FEM to calculate the magnetic flux of an ac/dc zero-flux current sensor equipped with a Hall element and analyzed the mechanism of operation. The analytical results agree well with experimental data. The clamp-on current sensor that we developed has a wide operating frequency range, from dc to 1 MHz, as well as high accuracy, to within ±0.5%.