A special high-frequency soft-switched DC/DC power supply for GCT gate driver

This thesis is devoted to the development of a novel parallel isolated power supply (PIPS) for the gate driver of integrated Gate Commutated Thyristors (GCT). The proposed PIPS is essentially a special high frequency soft switched DC/DC converter, integrating six parallel isolated power supplies in one module where each power supply generates a regulated dc supply for the GCT gate driver. In commercial GCT power supplies, a high-voltage isolation transformer is indispensable but highly inefficient in terms of cost and size, which can be significantly improved by the optimized transformer. In all, this design strives to achieve a general power supply for powering up the gate drivers of all types of GCT devices in all MV applications with minimal changes in configuration. In this thesis, the configuration of PIPS is presented and its operating principle is elaborated. The transformer optimization procedure satisfying the voltage isolation requirement of GCT gate drivers is extensively discussed. The performance of PIPS, including the front end DC/DC converter, zero voltage switching phase-shift full bridge (ZVS-PS-FB) converter, and the optimization of the transformer, is verified by simulations and experiments where a 360W laboratory prototype is built for the experimental use.