Investigation on 30MVA IGCT-based high power converter

Nowadays the medium and high voltage high power voltage source AC-DC-AC converters are widely used in various industrial fields. The integrated gate commutated thyristor (IGCT) is applied in these converters on a large scale due to its high rated voltage and current and other excellent characteristics. In this paper the investigation on the 30MVA IGCT-based large power voltage source converter is presented. The 30MVA converter is composed of two 15MVA IGCT-based five-level converters and the outputs of the two converters are in parallel connection. Each phase of the five-level converter is composed of two IGCT-based three-level neutral point clamped (NPC) legs in an H-bridge form. The detailed topology design of the 30MVA large power converter is introduced in this paper. The modularization design is adopted in the converter and the module of IGCT-based three-level NPC legs has been developed. The switching characteristics of IGCT are investigated and experimented on. One type of carrier-based modified in-phase disposition (IPD) modulation scheme is researched and simulated.