Development of Hybrid Excitation Characteristics of Superconducting Homopolar Generator

With the proposal of NASA’s N+3 future aircraft research program in the United States, high-power aviation electric propulsion technology with low fuel consumption and low pollution has increasingly become a hot research direction in the field of aviation power. The superconducting homopolar generator has been studied as an important alternative due to its simple, compact and suitable for high-speed operation. In this paper, a new hybrid excitation superconducting homopolar generator with permanent magnet auxiliary excitation between the rotor pole shoes was proposed for the serious magnetic leakage of superconducting homopolar generator. Firstly, The structure and working principle of the hybrid excitation superconducting homopolar generator were initially presented, followed by the establishment of an equivalent magnetic circuit model. Secondly, a three-dimensional finite element analysis method was established for hybrid excitation homopolar generators, combined with the analytical method, explore the advantages of hybrid excitation compared with a single electric or permanent magnetic excitation. It is found that the output power of hybrid excitation superconducting monopole generator is significantly better than the sum of electric excitation type and permanent magnet type, and the reason is explained from the magnetic circuit.