Development of high resolution magnetic field measurements for switching arc diagnosis of low-voltage switchgear

A method of switching arc diagnosis by means of magnetic field measurement and iterative determination of current paths is presented. First results, show the feasibility of the proposed method. By measuring the magnetic field outside of the switching device with a high spatial and high temporal resolution magnetic sensor array, information is obtained on switching current behavior. A purpose built magnetic field sensor array is developed. Information on the arc and contact movement during switching is retrieved from magnetic field measurement by iterative 3D FEM field calculation.