Magnetic Field Distribution Around Superconducting Coils in Ferromagnetic Environment

Abstract

There are two kinds of high temperature superconducting motor (HTS) according to the angle of the superconductor's shape, one with the superconducting bulk and the other with the superconducting tapes. Using the superconducting tapes, HTS motors, whose superconducting magnets are located in the rotor, have been researched by many researchers and institutes. This paper research a novel HTS structure that the superconducting coils are placed in the slots of the stator made of ferromagnetic materials. This paper researches the magnetic field distribution of the superconducting coil in the slots and teeth of the stator. The electromagnetic field distribution under the influence of rotating magnetic field and ferromagnetic material is presented firstly. Then, considering the effect of coupling of AC current that flow in the superconducting coils, the distribution of magnetic field is further analyzed. Finally, in order to reduce the alternating current loss, a ferromagnetic slab is added beside the superconducting coils and the improved magnetic field distribution is researched. The simulation result shows that this method is instrumental in harvesting a decrease of the perpendicular flux density from the 0.34 T to 0.06 T.

AC loss in ReBCO pancake coils and stacks of them: modelling and measurement

“…First, the sign of the current density, J, influences J c through equation (5). This is in order to describe the surface barrier effect, responsible for the difference in the height of the peaks close to the ab direction (90 o and 180 o in figure 2) [33].…”

“…Although using DC superconducting coils in the rotor already provides many advantages for superconducting rotating machines [3], superconducting stators with sufficiently low AC loss further increase the efficiency and power per unit weight in all-superconducting motors [4]. In addition, using superconducting windings in the stator only, with permanent magnets in the rotor, requires a much simpler cryogenic system [5,6]. Actually, the DC winding of the rotor is under the influence of a certain ripple magnetic field from the stator; that is, a small AC field on a DC background.…”

Basic Study of IPMSM with High-Temperature Superconducting Wire Rod

“…Most HTS motors use superconducting magnets as rotor poles. However, this study discusses a HTS interior permanent magnet synchronous motor (IPMSM) with superconducting armature coils [1]- [5].…”