A New Kind of Superconducting Machine

The aim of this paper is to present a new concept of superconducting inductor for a synchronous machine. This inductor consists of two superconducting coils. These coils have the same axis and are fed by the same current. A superconducting bulk is placed between the two coils in order to obtain a variation of the flux density in the air gap. This bulk is surrounded by a ferromagnetic material to improve the distribution of the air-gap magnetic field. With the proposed superconducting inductor, we obtain an electrical machine which presents two poles with a high value of the magnetic field in the air gap. In order to show the feasibility of this new superconducting inductor, a prototype has been built, and experimental results are given in this paper.