An efficient HTS electromagnetic model combining thin-strip, homogeneous and multi-scale methods by T-A formulation

Abstract

Recently, combination models, in which two or more advanced methods are employed, have been studied to explore various approaches to simulating large-scale ReBCO coils efficiently. However, modeling the combinations could be more complex if the methods are not integrated well. In this paper, an ingenious combination of thin-strip, homogeneous and multi-scale methods is presented. In particular, we build the thin strips as both the analyzed HTS tapes and the boundaries of the homogeneous bulks where the non-analyzed tapes are merged. Thus, the coil geometry is re-constructed with several bulks, but the bulks’ boundaries and domains are tackled with different electromagnetic properties, and solved by T and A formulations, respectively. Firstly, we introduce the modeling process and highlight the differences and advantages over the previous models. Then, the accuracy of the proposed model is validated by comparing the results with those from the reference model based on a 2000-turn coil. The distributions of normalized current density, magnetic flux density and hysteresis losses from the two models are highly consistent, and the error of the total loss is less than 1%. Besides, the combination model is the most time-saving among all the advanced models. Furthermore, the proposed method can be applied in 3D simulations, and the high accuracy and efficiency are validated by simulating a 50-turn racetrack coil. The study shows that the combination method is a feasible approach to simulating large-scale HTS coils, and can be a powerful tool to design and optimize HTS systems.