Modeling and design of high transient current multicell converter using intercell transformer: Application to HVDC cable diagnostic

This paper presents the design of a new application for parallel multi-cell converters. The aim is to setup a portable system that can inject a 12000 A current within 2s in the conducting core of a HVDC cable, and determinate the distribution of electrical space charge through the insulation using the Thermal Step Method (TSM). The proposed structure will be constituted of ten paralleled coupled multiphase buck converters using InterCell Transformers (ICT). The magnetic coupling used in this structure does not need the use of any additional filters. An analytical model is developed in order to quantify the magnetic flux through the magnetic core and to optimize the ICT design. A prototype was built in order to validate the transient principle and to confirm the magnetic coupler analytical model results. © 2013 Lavoisier.