Setup and performance of a capacitive 300 kJ pulsed power supply system for ETC-gun investigations

Due to the electrical power supply requirements of electrothermal chemical guns in terms of pulse duration and shape as well as voltage, current and power magnitudes, sophisticated pulsed power supply systems are necessary. Two capacitive 300 kJ pulsed power supply systems have been designed, setup, tested and installed in Sweden by TZN under contract on FMV in order to support the Swedish ETC-Gun programme. Each capacitor bank consists of four 75 kJ units. Triggered vacuum switches, crowbar diode circuits and adjustable inductors with six inductance values are connected to each high voltage discharge capacitor. The design of the capacitors enables an operation at either 11 kV or 22 kV at full energy. A load bypass switch as well as overvoltage varistors are installed in the output terminal of each system. Computer control systems with consequent fibre optic signal transmissions provide a reliable and safe operation of the systems. Each unit can be charged to a different voltage during the charging process. Simultaneous and sequential firing of the units is provided. Both systems are installed in a 20 feet ISO container each providing the entire infrastructure. The computer control system is designed to operate both systems together in order to double the features of the systems. After giving the specifications the design and the technical solutions are described. A number of test results is presented which demonstrate the performance complexity of the system.