Analysis of Magnetic Field Distribution in a Hall Sensor Based Protection

Abstract

The influence of magnetic field distribution on performance of a Hall sensor based protection is presented and discussed. Noise level at output of the sensor due to asymmetry of 3-phase load as well as due to various location of the grounded phase with respect to the core CT air gap was inspected. Sensitivity of the directional ground fault protection including current and phase errors variations was considered depending on parameters of a magnetic circuit applied. To meet requirements if about selectivity an auxiliary magnetic shield located inside CT directly on the cable feeder was applied. It was found to improve the protection performance significantly. On the basis of both simulations (2D) and results of experimental investigations the conclusions about designing procedure of the effective ground fault protections as well as about further simulations of three dimensional field to make the optimization perfect and easy to handling are formulated. Il. 11, bibl. 2 (in English; summaries in English, Russian and Lithuanian).