Studies on deformation of a 600 kJ modified D-shaped superconducting coil caused by electromagnetic force

As the mechanical causes for instability and loss in superconducting coils become more pronounced as coils increase in scale, it is important to understand the physical behavior of such failure when developing highly reliable and efficient SMES's of a practical scale. However, it is difficult to understand the mechanical behavior of superconducting coils, especially the local deformation or displacement of coil components. It is helpful to use a model to simulate the mechanical behavior of superconducting coils when discussing the instability and mechanical loss caused by such mechanical factors. A simulation model was developed to show the nonlinear mechanical deformation of a modified D-shaped elemental coil with a Rutherford type conductor in a 1 kWh SMES. The nonlinear characteristics of the conductor were explained by the frictional slip between two layers in the conductor. FEM analysis conducted using this model explained well with the mechanical deformations measured in the coil.