TY - JOUR
AU - Harrowell, R V
AB - Letter to the Editor In his recent review (1972) of superconducting electrical machines Dr Mulhall, referring to turbo-alternators, declares that, 'as in conventional machines, the superconducting field winding must rotate, as the rotor could not be made to carry the full armature current.' He then states that essentially the same conclusion was reached by me in a recent paper (Harrowell 1972). Mr A D Appleton (1972) has also quoted my paper in support of this particular argument. I should like to take this opportunity to set the record straight on our thinking at CERL on the configuration of large superconducting alternators. While we are fully aware of the difficulties besetting a superconducting alternator with a rotating armature, we are not convinced that they are unacceptably greater than the alternative problems presented by a machine with a rotating superconducting field winding. The major objection to the former machine is the difficulty of collecting, at a phase- phase PD of about 30 kV peak, three rotor currents that are about five times greater than the field current that is transferred at present through two sets of brushes and slip rings at 1 kV. There are two major difficulties with the stationary-armature 
TI - Superconducting electrical machines
JF - Physics in Technology
DO - 10.1088/0305-4624/4/1/105
DA - 1973-01-01
UR - https://www.deepdyve.com/lp/iop-publishing/superconducting-electrical-machines-jL6xEcPuRt
SP - 80
VL - 4
IS - 1
DP - DeepDyve
ER -