Development of a load inductor in a single pulse test circuit

Abstract

In this work, with the purpose of reducing the surrounding disturbance field, a to-roidal inductor for a single pulse test circuit is designed and a prototype is manufac-tured. The manufactured toroidal inductor is 355μH while the existing cylindrical in-ductor is 270μH. In addition, the designed inductor together with the existing cylindrical inductor of the single pulse test circuit are implemented in the COMSOL Multiphysics® program in order to make a comparison of the magnetic field and to investigate the disturbance of both type of the inductors on the test results of the single pulse test circuit. According to the test results and the comparison made in COMSOL Multiphysics®, it is observed that the magnetic field of the toroidal inductor is much less than the one of the cylindrical inductor for the same current (1.8kA) and inductance value (270μH). The magnetic field of the toroidal inductor shows a dramatic reduction compared to the magnetic field of the cylindrical inductor. At a horizontal distance of 10cm from the inductors, the magnetic field is reduced from 42.798μT in the cylindrical inductor case to 2.423μT in the toroidal inductor case; likewise at a vertical distance of 10cm from the inductors, the magnetic field is reduced from 15.999μT in the cylindrical inductor case to 0.850μT in the toroidal inductor case. Furthermore, 40A is applied to the inductors in order to measure and compare the magnetic field of the existing 270μH cylindrical inductor and 355μH manufactured to-roidal inductor. The measurement shows that at a distance of 10cm, the magnetic flux density is reduced from 307μT in the cylindrical inductor case to 0.28μT in the toroidal vi inductor case; however the inductor value of the toroidal inductor is higher than cylin-drical inductor (355μH compared to 270μH). Moving the circular loop 10cm away from the cylindrical inductor, the magnetic field reduces by 43%, likewise when the distance increases to 20cm, the magnetic field reduction is 61%. In this thesis a significant reduction of magnetic field in the toroidal inductor com-pared with cylindrical inductor is achieved. At the moment of writing this report, so far, the highest current level and voltage level applied to the manufactured toroidal inductor are 2000A and 3600V, respectively.