Abstract

High-temperature superconducting (HTS) flux pumps are a promising candidate for achieving contactless energization of HTS coils, providing the possibility of eliminating bulk current leads and the associated heat burden. HTS flux pump systems contain multiple HTS components, such as an HTS stator or receiver, and HTS coils, all of which can impact the system performance due to their intrinsic non-linear electromagnetic properties. To characterize the overall behavior of flux pump systems while retaining a precise characterization of local superconducting effects, we proposed a methodology to couple different types of superconducting numerical models through a circuit model. Specifically, superconducting constituent parts are presented in the electrical circuit as global voltage parameters obtained by numerical models, and the current from the circuit is fed back to the numerical models to realize strong coupling between each model. Here we verify the effectiveness and versatility of this approach against experimental measurements, for both dynamo-type HTS flux pumps and transformer-type HTS flux pumps. For the dynamo-type HTS flux pump, the 3D minimum electromagnetic entropy production (MEMEP) method is used for modeling the HTS stator; for the transformer-type HTS flux pump, an H-formulation finite-element method (FEM) model is used for modeling the magnetic coupler and HTS bridge. In both cases, we use a T-A formulation FEM model to describe the HTS coil. The results show that, by using the proposed approach, the dynamic charging process can be well reproduced. More importantly, the dynamic losses and the impact of the critical current of the HTS coils can be considered as well.