Impulse current withstand capability of coaxial cables in high current applications

A coaxial medium voltage cable has been tested as a means to connect the high current pulse generator to the load coil in magnetoforming applications, at single pulses of ca. 100 mus duration, and at amplitudes between 30 and 140 kA. The radial deformation (expansion) of the cable was detected with a high-resolution, high-speed camera as a function of the current amplitude. We observed dynamic changes of the cable diameter at currents above 80 kA, reaching up to 1.26 mm increase in diameter at 142 kA pulse amplitude. The measurements are used to estimate the operating range of these cables.