High voltage, high current, high di/dt solid state switch

A high voltage, high di/dt, modular solid state switch intended to replace thyratrons in high power modular applications is under development. This paper describes the results of testing a switch module with a 10 kV, 6 kA, 30 kA/microsecond, 3 /spl mu/s PFN, under normal and load fault conditions. Included are data on switching losses and thermal performance during repetition rate operation. Experiments using alternate PFN´s to obtain higher di/dt operation are discussed. Initial results of multiple module tests with a 30 kV PFN are presented. The switch module uses three 5 kV, 15 mm diameter, thyristors connected in series. These thyristors were developed specifically for pulsed power applications, and have an interdigitated gate/cathode geometry to minimize turn-on losses and maximize di/dt. The module´s trigger circuit uses the switched energy to drive the thyristor gates, eliminating the need for an external gate drive power supply. A 35 V, 1 A, 50 ns risetime pulse triggers the module. The total switch inductance is <50 nH, if the case is used as the return current path. The compact, economical, modular package design facilitates the development of drop-in replacement switches for thyratrons with voltage ratings of >60 kV.