Numerical Multiscale Model For Ac Loss Calculation Of Large-Scale Hts Solenoid Magnets

A numerical multiscale model is used for the calculation of ac loss in a two-dimensional (2-D) planar model and proves advantageous with regard to time and memory requirements. In this study, we improve the calculation accuracy and apply a multiscale model to a 2-D axisymmetric model of a high-temperature superconducting solenoid magnet by using an iteration method for the background field estimation. The calculation results are compared with those of the H-formulation model, homogenization model, and multiscale model with a J(0) uniform background field estimation method. The iteration method speeds up the calculation by 7.7 to 12.9 times and reduces the error of the average ac loss to 6.71% and the error of the ac loss peak value to 5.95%. In addition, the iteration method is superior to the homogenization model in terms of calculation speed and accuracy as the computational complexity increases.