Studies on Deformation of a Modified D-shaped Superconducting Coil caused by Electromagnetic Force

Abstract

As mechanical causes for instabilities and losses of superconducting coils become dominant with a scale of them, it is important to understand mechanical behaviors of them in developing a practical scale SMES with high reliability and high efficiency. But to know the mechanical behaviors in the superconducting coil, especially local deformation or displacement of components of it is difficult. Therefore it might be helpful to use a model which can simulate the mechanical behavior of superconducting coil for a discussion of the instability and mechanical loss caused by the mechanical effects.
In this paper, a simulation model which is developed for the nonlinear mechanical deformation of a modified D-shaped elemental coil with a Rutherford type conductor for a 1 kWh SMES is shown. The model uses nonlinear mechanical characteristics of the conductor measured by a 3-point bending test. The nonlinear characteristics of the conductor are explained by the frictional slip between two layers in the conductor. FEM analysis with this model agreed well with measured mechanical deformation of the coil.