A new generation emitter turn-off (ETO) thyristor to reduce harmonics in the high power PWM voltage source converters

This paper introduces the new generation emitter turn-off (ETO) thyristor, which improves the output waveform quality of the high power PWM voltage source converters. Besides its 4000 A snubberless turn-off capability, high di/dt turn-on capability, and short turn-off storage time, the new generation ETO has a unique function: when the upper and the lower ETOs within a converter phase leg are connected with two optical fibers, the ETOs can receive the ideal complimentary (without dead-time) PWM signals and solve shoot-through problem. The new generation ETO is able to eliminate the dead time requirement and reduce harmonics in the PWM voltage converters. In this paper, the principle of the new generation ETO is described, and the experimental results of the ETO based PWM voltage source converters are presented