A 16MJ compact pulse power system for electromagnetic launch

Abstract

This article devotes itself to a compact pulse forming network (PFN) of 16MJ for rail gun. The PFN is composed of 156 pulse forming units (PFU), and each unit stores 103kJ energy. The main components of PFU are energy storage capacitor, pulse-shaping inductor, pulse thyristor, crowbar diode and Rogowski coil for current-measuring. The rated voltage of PFU is 10.8kV. Metallized PP film is used as dielectric material of the pulsed capacitors, whose energy density is 1.5 kJ/L and whose life time is above 2000 shots. The pulse thyristor with a wafer diameter of 4 inches can endure the pulse current of 150kA. For convenience of integral assembling, the crowbar diodes also adopt 4 inches wafers. The trigger device of thyristor takes the energy from the main pulse capacitor of 103kJ, so the common insulating transformer can be abandoned. This mode decreases the volume and weight of the trigger unit greatly. Single PFU produces the pulse current of 120kA, and its energy storage density is 0.88MJ/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . The trigger time of every unit in the 16MJ PFN can be adjusted flexibly for the different shape of the total current. All PFUs discharge at the same time with the load of rail gun so that they can produce the spire current of 3-4MA. And they can be triggered at some special interval in order to achieve the quasi-flat wave, which benefits the manufacture of the rail and the armature. In a whole, the PPS consists of PFN, charging power supply, control system and current junction station. Its configuration is so compact that all components can be placed in 2 big frames. Every frame with size of 7.5m*2.2m*2.3m is suitable to be transported in a container.