“…These modifications will increase the losses and reduce the dynamic performance, so a system with fewer GTOs connected in series provides better voltage sharing, and improves efficiency and dynamic performance [51]. Recently, however, the technology that allows the robust, reliable and cost-efficient series connection of GTOs is industrially mature [100]. Especially, in [102] , with a digital control circuit for extremely accurate adjustment of gate turn-off timing in units of 0.1 μs, the up to 16 GTOs connected in series shared the voltage uniformly in the turn-off period.…”