Optimization of HTS Superconducting Solenoid Magnet Dimensions for Maximum Energy Density

Abstract

Superconducting coil provides enormous amount of stored energy inside its magnetic field. Such a pure inductive superconducting (SC) coil can be designed for high power density or high energy density depending on coil dimensions and inductance based on the prerequisite of application. In this paper, a design procedure is developed to optimize dimensions of a high-temperature superconducting (HTS) coil to store maximum energy for a given length and critical properties of HTS tape. A minimum volume constraint (MVC) is developed to confine the variation of aspect ratios to keep the coil volume constant, thereby limiting the material, cryogenic and vacuum costs of HTS coil. A global optimum inner diameter is established by MVC, with which the optimum dimensions can be reached directly. Multiple constraints such as coil volume, stacked pancake arrangement, HTS tape length and mechanical properties are considered. The electrical, magnetic and mechanical parameters for different dimensions are then found by finite element method (FEM). The proposed method is applied to different lengths of 1G and 2G HTS tapes. The optimum dimensions of maximum stored energy are decided which gives a solenoid coil of maximum energy density.