Electromagnetic design of turbogenerator stator end regions

The authors review the electromagnetic design of turbogenerator end regions. Three-dimensional finite element analysis is employed to investigate existing design concepts and evaluate their effectiveness in reducing stator core end losses. The solution method includes both eddy current reaction and magnetic nonlinearity effects. Concentration is made upon the various sources of axial flux, their relative magnitudes and their vector addition during load conditions. A number of design features are considered in some detail, illustrating how the manner in which they influence losses on load is generally very complex. In many cases it is shown that these features result in a number of important effects which were not perceived at the time of their introduction