Novel Hybrid Excitation High Temperature Superconducting Homopolar Inductor Alternator for Aviation Turbo-Electric System

The high temperature superconducting homopolar inductor alternator (HTS-HIA) connected with a high-speed gas turbine can achieve higher efficiency and higher power density. However, limited by the insulation and quench of the HTS winding, the HTS-HIA cannot change excitation current quickly to meet the requirements of output voltage regulation. To satisfy the load demand of multiple voltage levels, a novel hybrid excitation HTS-HIA (HEHTS-HIA) is proposed in this paper. Its excitation windings include a HTS winding and an adjusting winding made of copper wire. In steady-state operation, only the HTS winding carries the excitation current, while the adjusting winding only operates when the output voltage needs to be regulated. Firstly, the structure and operation principle of the proposed HEHTS-HIA is illustrated. To describe the principle of voltage regulation, the equivalent circuits of HTS winding and adjusting winding are established. Then, the electromagnetic performance of HEHTS-HIA is analyzed, including adjusting characteristics, response speed, transient characteristics and output performance. The results show that the proposed HEHTS-HIA can achieve a full range of voltage regulation under the premise of ensuring the safety of HTS winding, indicating that the proposed HEHTS-HIA is a promising candidate for the application of aviation turbo-electric system.