Electrical machine has non-magnetic outside of rotor envelope with electrical conductivity selected so magnetic fields generated by alternating voltage harmonics are absorbed

摘要

The machine has a machine housing (2) with a stator (4) carrying a stator winding (5) for connection to an a.c. voltage and arranged around a rotationally mounted rotor (6) with a superconducting winding (10) carried by a winding carrier (9). The rotor winding and carrier are arranged in a rotor envelope (12) for thermal insulation. The outside of the envelope is non-magnetic and the value of the electrical conductivity of the outside of the envelope is selected so that the magnetic fields generated by the a.c. voltage harmonics are absorbed.