A 100 Kilovolt Phase Control Thyristor Switch Stack

A 100 kilovolt phase control thyristor switch stack has been successfully developed and tested at the Madison Symmetric Torus (MST) plasma physics research facility. A set of eighteen thyristors were connected in series and a special gate driver circuit was developed to fire all eighteen thyristors simultaneously. Tests were performed by charging a capacitor to 100 kilovolts and discharging it through the thyristors into a resistive load. Initial tests were successfully performed at an energy of 10 kilojoules. A second device was constructed using twenty four thyristors that is fully operational at 100 kilovolts and 70 kilojoules. These devices are for pulsed power applications and general switching of high voltages up to 100 kilovolts.