HTS Motor Performance Evaluation by Different Pulsed Field Magnetization Strategies

A fully high temperature superconducting motor has been built in the EPEC laboratory at the University of Cambridge, U.K. Two different pulsed field magnetization (PFM) strategies have been implemented for studying the magnetization of a cylindrical rotor designed by an asymmetric array of superconducting bulks. Asymmetric or uneven distribution of superconducting bulks could occur when the size of the superconducting bulks is compromised due to the curvature of the rotor and the design aims to cover the largest area as possible for the magnetic poles. It is certainly an unusual design which nevertheless deserves to be explored, as possible misalignments between the superconducting poles to be magnetized by PFM can be studied when an uneven arrangement of columns of superconducting bulks is implemented for along a cylindrical shaft. In the first of the PFM strategies, only six out of 15 columns of superconducting bulks have been effectively magnetized, and the performance of the resulting rotor has been compared with the case when the PFM strategy leads to the magnetization of up to 93% of the superconducting bulks. The advantages and disadvantages of each of the PFM strategies are discussed.