GB1395152A - Altering current dynamo-electric machine windings - Google Patents

Abstract

1395152 AC dynamo-electric machines INTERNATIONAL RESEARCH & DEVELOPMENT CO Ltd 1 May 1972 [1 Feb 1971] 3620/71 Heading H2A In an A.C. dynamo-electric machine, e.g. a superconducting alternator shown in Fig. 2 or an iron-wired machine having an air-gap armature winding, having a stationary A.C. winding carried by a non-magnetic hollow cylindrical support structure coaxial with a rotor, the winding includes two coaxial cylindrical layers of conductors X 1 , X 2 , Y 1 , Y 2 , Fig. 1, or 11, Fig. 2, each of which conductors is composed of one or more helical sections with each conductor of a layer having the same lateral relationship to the other conductors of the winding as every other conductor of that layer and all conductors of each layer being at the same radius from the rotor axis substantially throughout the conductor lengths and, between the ends of the conductors of the two layers, end connections which complete the turns of the winding each of which turns comprises at least one conductor of the first layer connected in series with at least one conductor of the second layer each end connection extending substantially radially between a conductor end of the first layer and an adjacent conductor end of the second layer. Each conductor may form a single helical section as shown, or two equal length sections of opposite sense, and may be finely divided and twisted, directly fluid cooled via a water manifold 20, and overlap the rotor winding by a considerable amount. The support structure of Figs. 3 and 5 comprises an assembly of non-conducting, e.g. densified hardwood rings 25 each having two circles of helically inclined holes 21, 22 through which preformed helical winding conductors are threaded. Alternatively, each such ring may be sequential (Fig. 6), or the structure may comprise three juxtaposed hollow cylinders having winding - receiving helical grooves (Figs. 7 ... 10). In the alternator of Fig. 2 the stator conductors 11 are non-superconducting and the rotor field winding 10 is cooled by liquid helium circulated through a refrigerator 14 via supply and return connections 15, the space within the rotor being evacuated via a vacuum connection 16; a rotor outer part 13 serves as a vacuum casing and an eddy current screen, and a Cu screen 19 surrounds both windings.