Development of a Compact 450-kJ Pulsed-Power-Supply System for Electromagnetic Launcher

Abstract

A 450-kJ pulsed-power supply (PPS) for electromagnetic launcher has been built up. It consists of six 75-kJ pulse forming units (PFUs). Each PFU is composed of a 75-kJ capacitor (1000 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\mu \hbox{F}$</tex></formula> /12.2 kV), a thyristor stack as main switch, a diode stack as crowbar, a specific pulse-shaping inductor <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$(15\ \mu\hbox{H}/18\ \hbox{m}\Omega)$</tex></formula> , and a coaxial cable. The peak value of the output current of one PFU is 85 kA with a peak time of 190 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\mu\hbox{s}$</tex></formula> . The influencing factors of overvoltages on the series thyristor valves are studied by experiments and simulations based on PSCAD/EMTDC. A proper protection is used to prevent the series thyristor valves from being damaged by overvoltage when a switch is turned on. At the end, the total discharge currents of the PPS test with a short-circuit load and a railgun load are presented, respectively.