Research on Electromagnetic Simulation Method of Fusion High-Temperature Superconducting Magnet System

ObjectivesThe application of high-temperature superconductivity (HTS) magnet system is an important technical route for future tokamak devices. However, the magnetic field anisotropy of the HTS tape and the complex conductor structures greatly increase the complexity of the simulation in the electromagnetic design stage of the HTS magnet system of the fusion device. It is necessary to carry out the corresponding research on the electromagnetic simulation and simplified methods.MethodsThe finite element simulation software COMSOL was used to establish the overall electromagnetic simulation model and various simplified models of the HTS magnet system, and the related electromagnetic properties were simulated and compared.ResultsThe calculation results of the central magnetic field and the maximum ripple of plasma are mainly controlled by the magnetic field generated by the toroidal field (TF) coil. However, the TF coil has little influence on the magnetic field distribution on the central solenoid (CS) coil. When the detailed structure of the conductor is combined and the magnetic field anisotropy of the HTS tape is considered, the calculated results of the vertical magnetic field show a large difference compared with the overall model.ConclusionsThe TF coil can only be considered in the calculation of the relevant electromagnetic parameters in the plasma region, and the TF coil can be ignored in the analysis of the magnetic field on the CS coil. In addition, by combining the average current distribution of the conductor structure, the simulation error of the vertical magnetic field of the HTS tape can be effectively reduced.