Modelization of current sensors by finite elements method

Abstract

Accurate high current measurements require the use of devices which are difficult to calibrate since neither it is easy to obtain the current needed nor to set up a proper testing rig in the laboratory. Nevertheless, a straight wire carrying a high current can be replaced by an N-turn coil fed with an N-times lower current. In this paper, the uncertainty associated with the use of N-turn coils in calibration of clamp-type current meters has been estimated using the finite element method (FEM). The wire carrying the current to be measured is often incorrectly located with respect to the sensor. Hence, the effects of excentricity or rotation of the sensor with respect to the straight wire are also analysed by FEM and measured at 50 Hz in our metrology laboratory accredited by European Cooperation for Accreditation (EA).