IGCT for Induction Heating
A. Weber, E. Carroll, M Frecker
Today Integrated Gate Commutated Thyristors (IGCT) are widely used for different applications such as medium voltage drives (MVD) and interties. Application specific devices have been developed such as reverse conducting IGCT for voltage source inverters (VSI) and reverse blocking IGCT for current source inverters (CSI). MVD switching frequencies are in the range of 500 Hz to 1kHz and the trade-offs between switching losses and on-state voltage drop are optimised accordingly. For other applications, such as inverters for induction melting and breakers, the switching frequency is lower and can range from a single shot (static breakers) to a few hundred Hz and IGCT with very low on-state voltage drop have recently been developed for these applications. While low on-state 4.5kV devices for breakers have been available for some time new 6kV IGCT have recently been developed for induction melting and will be presented at the end of this paper.