[AP6] Rotating machines 2

10:30 AM - 10:45 AM JST(1:30 AM - 1:45 AM UTC)

[AP6-03] Assembly and preliminary tests of a 250 kW partially superconducting machine

Remi DORGET⁴, Walid Dirahoui¹, *Jean LEVEQUE¹, Thierry LUBIN¹, Kevin BERGER¹, Mathis DURAND¹, Adrien CIPRIANI³, Paul GNING², Christophe VIGUIER² (1. Université de Lorraine, GREEN (France), 2. Safran Tech, Electrical & Electronic Systems Research group, Rue des Jeunes Bois, Châteaufort, 78114 Magny-Les-Hameaux (France), 3. Absolut System, 3 rue Raymond Chanas, 38320 Eybens (France), 4. Airbus UpNext SAS, Toulouse (France))

Keywords:

Superconducting Motor,Bulk HTS,Axial field machine,High Temperature Superconductors,Synchronous Machine

Experimental Investigations on the Cooling, Performance, and Equivalent Modeling of a Superconducting Coil at 30 KThe first stage of the experimental campaign is devoted to the characterization of a superconducting coil under cryogenic conditions at 30 K. This intermediate temperature is particularly attractive for high-temperature superconductors (HTS), offering enhanced critical current while avoiding the complexity of liquid helium. The experiments aim to assess cooling behavior, electromagnetic performance, and equivalent modeling as preparatory steps toward system-level applications.Cooling and Thermal ConditionsReaching 30 K requires an efficient cryogenic system combining a cryocooler, thermal links, and adequate insulation. Temperature sensors distributed along the coil ensure uniform cooling and prevent harmful gradients. Once steady-state operation is established, the correlation between thermal stability and electromagnetic response is evaluated, providing insight into the effectiveness of the cooling design and its impact on coil performance.Hall Effect InstrumentationTo capture magnetic dynamics, the superconducting pellets are equipped with Hall effect probes. These sensors, calibrated for cryogenic operation, measure local flux density with high precision. Their distributed arrangement enables mapping of flux penetration and redistribution, offering a detailed picture of the magnetic environment. The instrumentation is critical for linking applied excitations with the coil’s internal field distribution.Shielding VerificationThe superconducting state is further examined through shielding experiments. By applying external magnetic fields and recording the Hall probe signals, the bulk’s ability to screen magnetic flux is quantified. The results confirm efficient shielding, validating both superconductivity and structural homogeneity. This step is essential before subjecting the coil to higher electrical stresses.No-Load and Short-Circuit TestsThe second experimental phase addresses operational performance. No-load tests determine intrinsic parameters such as inductance and flux distribution without external constraints. These experiments reveal the coil’s current-carrying capacity, dynamic stability, and loss mechanisms. The Hall probes provide real-time information on flux redistribution during these regimes.Equivalent Circuit ModelData collected from the above tests are analyzed to establish an equivalent circuit model of the superconducting machine. Parameters such as inductance, residual resistance linked to flux motion, and effective losses are extracted. This model provides a simplified yet accurate representation of the coil, supporting predictive simulations and enabling direct comparison with conventional copper-based systems.ConclusionThe results demonstrate that the system can be cooled and reliably operated at 30 K, exhibiting strong shielding and stable performance under both steady-state and transient tests. Hall effect instrumentation proves essential for magnetic diagnostics, while the equivalent model offers a valuable design tool. These findings confirm the potential of HTS coils for advanced electrical machines and pave the way for further integration studies.
Acknowledgment The authors would like to thank the Direction Générale de l’Armement (DGA), the Agence de l’Innovation de Défense (AID), and the Agence Nationale de la Recherche (ANR).