Investigation of the transient behaviour of a superconducting magnetic energy storage (SMES) generating high power pulses

A method for calculating transient voltages in superconducting magnets has been developed. The prediction of over voltages is an essential requirement in avoiding insulation damages in expensive high‐power magnets. A single coil of a modular built Superconducting Magnet Energy Storage (SMES) was modelled as a strongly coupled R‐L‐C network with 8556 mutual inductances. The calculated transient behaviour of the model corresponds well to the measured unit function response of the investigated coil. The coil was designed with respect to the fast repetitive ramping of the SMES. Resonant oscillations are well damped by the mixed matrix Cu/CuNi/NbTi wire used. Due to the high safety margin of the insulation the maximum over voltages could not endanger the winding. A comparison of the results with those of large superconducting fusion coils leads to the recommendation that during the design stage of larger sized SMES a numerical investigation of the resonance behaviour of the system should be performed.