New Developments in Armature Winding Arrangements for Large Turbine Generators [includes discussion]

The designer of electric machinery is continually challenged to obtain greater output from each pound of material. He is also challenged to further the search for successful design solutions to unsolved problems of long standing. Recent developments in armature winding design for turbine generators have made possible substantial progress in these directions. Two new classes of generators have been developed which make machines of a given rating physically smaller and which greatly extend the possible ratings of the largest machine. The first class, which this paper proposes to cover, increases the capability of the stator without altering cooling methods. This is accomplished by new electric arrangements of the armature windings. The second class, which will be discussed here briefly for comparison, deals with a stator design with improved means of heat removal. New methods of field winding ventilation have also been developed which make possible rotors which match the increased capability of the stator. Progress in this direction is discussed in a companion paper.1 In the design of double-winding generators, many restrictions of long standing have been removed by the development of new armature winding arrangements.