Superconducting high current magnetic Circuit: Design and Parameter Estimation of a Simulation Model

The Large Hadron Collider (LHC) utilizes superconducting main dipole magnets that bend the trajectory of the particle beams. In order to adjust the not completely homogeneous magnetic feld of the main dipole magnets, amongst others, sextupole correctcorrector magnets are used. In one of the 16 corrector magnet circuits placed in the LHC, 154 of these sextupole corrector magnets (MCS) are connected in series. This circuit extends on a 3.35 km tunnel section of the LHC. In 2015, at one of the 16 circuits a fault was detected. The simulation of this circuit is helpful for fnding the fault by applying alternating current at different frequencies. Within this Thesis a PSpice model for the simulation of the superconducting corrector magnet circuit was designed. The physical properties of the circuit and its elements were analyzed and implemented. For the magnets and bus-bars, sub-circuits were created which reflect the parasitic effects of electrodynamics and electrostats. The inductance values and capacitance values of the magnets and the bus-bars were defined by geometric calculation, geometric simulation and evaluation of circuit simulations. PSpice and Matlab are the used software programs for simulations and evaluations. The real fault in the circuit is defined as a ground fault. By integration of the inductive coupling between the bus-bars, it is also possible to mimic the behavior of the circuit at ground fault conditions. Through the final simulations it was possible to determine the possible position of the real earth fault on a small part in the tunnel section.