Magnetic Crosstalk Minimization in Optical Current Sensors

We demonstrate that the magnetic crosstalk-induced errors associated with point-type optical (Faraday) current sensors working in three-phase electric systems may be minimized by properly designing the geometry of the system. We propose a novel architecture in which the optical path inside the magnetooptical material is parallel to the direction of the neighboring conductors, except in a small loop around the sensor head. This renders the crosstalk effect at least one order of magnitude smaller than in conventional Faraday sensor architectures.