Parametric Investigation of Pulse Transformer for Current Enhancement in Capacitive System

The design of a co-axial pulse current transformer has been numerically as well as experimentally investigated to meet the contradicting need of gaining high peak current along with long rise time from a capacitive pulse power system. The crucial design parameters of co-axial pulse transformer such as its loop radius and radius of outer conductor are numerically optimized with respect to its current gain, output voltage and current rise time using COMSOL® Multiphysics software. The versatility of design has been improved by deriving output current in two channels, which may be joined together for current gain or may be used independently as per the need of application. Based on the simulations, a two-channel current transformer is developed and tested with a 0.6 mF capacitor bank. It is found to generate a total output current of 121 kA at an input current of 65 kA of rise time 60 µs at 12.5 kV charging voltage in a short-circuit load.