A Method to Improve Volume Energy Density for HTS Coil

This paper investigates strategies to improve the volume energy density of superconducting solenoidal energy storage coil. A multiple population genetic optimization algorithm combined with MATLAB and COMSOL is used to optimize the structural parameters of the solenoid coil with rectangular cross section. The maximal radial magnetic flux densities, critical currents, volume energy densities, and tapes utilizing rates of rectangular and other three different step-shaped cross-sectional solenoidal coils are analyzed and compared. The coil with inner and outer step-shaped cross section is proposed as the topology to improve the volume energy density. The current injection strategy that different step coils are supplied with different currents according to the magnetic flux density distribution is employed to further improve the volume energy density.