Evaluation of the GTO for 270 MVA interrupter applications

The fundamental problem of interrupting a direct current is producing a current zero which will allow for the elimination of current flow. Historically, external circuits have been used to extinguish a plasma (arc) conducting medium by counterpulsing the arc current to zero. Preliminary results show that solid-state dc interrupters utilizing gate turnoff thyristors can provide for reduced capacitive energy storage requirements over vacuum interrupters and SCRs in creating a current zero. Additionally, the hardware required in the gate circuit of the GTO is significantly reduced over the counterpulse circuits in vacuum interrupters and SCRs by taking advantage of the turn-off gain available in the GTO. Interrupters designed around the GTO can have applications in the power conditioning and protection circuits of particle accelerators and fusion reactors