Design and implementation of a non-contact magnetic field measurement based fault location system for overhead transmission line

As the rapid development MEMS (micro-electromechanical systems) packaging technology and magnetoresistance material technology, MR (magnetoresistive) sensors based on magnetoresistance effect which can carry out point measurement of magnetic field may change the measurement techniques in power systems. The currently available fault location of overhead transmission line approaches are mainly based on traveling-wave technique and impedance-based measurement technique. The novel approach based on non-contact measurement of magnetic field is advantageous over traditional approaches in that it is independent of the distributed line parameters and has a location error smaller than one span. In this paper, after a brief reviewing of the whole system architecture, design of a sensor prototype and the associated monitoring software are presented, and tests are performed to verify the functionalities of the designed system. The sensor is developed based on a 3-D AMR (anisotropic magnetoresistance) sensor and the software supports GIS interface, making the fault location intuitively clear and convenient.