Investigation on IGCT-based NPC/H-bridge large power converter

Abstract

Nowadays the medium and high voltage large power AC-DC-AC converters are widely used in various industrial fields. The integrated gate commutated thyristor (IGCT) is applied to these converters on a large scale due to its high rated voltage and current and other excellent characteristics. In this paper the investigation on IGCT-based NPC/H-bridge large power converter is proposed. The converter is composed of two IGCT-based five-level NPC/H-bridge converters and their outputs are in parallel connection. Each phase of the five-level NPC/H-bridge converter is composed of two IGCT-based three-level neutral point clamped (NPC) legs in an H-bridge form. The converter adopts modular design and the module of IGCT-based three-level NPC legs has been developed. The turn off characteristics of IGCT are investigated and tested. At last one type of carrier-based modified in-phase disposition (IPD) modulation scheme is simulated.