Design on the protection inductor for the capacitor bank of Wuhan Pulsed High Magnetic Field facility

For the protection of the thyristor switches of the 12 MJ, 25 kV capacitor bank at the Wuhan Pulsed High Magnetic Field Center, inductors are designed to be placed in series with the switches to limit the current at 30 kA when the magnet is short in the circuit. To lower the interference of the stray field of the inductor to the environment, the inductor is designed as a toroidal system consisting of bitter coils evenly distributed in the perimeter of the circle. The structure of the system and the electromagnetic and mechanical analysis are described in this paper.