A Method to Calculate Turbogenerator End Region Fields and Losses and Validation using Measured Results

Modern turbogenerators are designed with high specific loadings. One of the consequences of this is the requirement to design the machine to minimise the size and effects of stator end region leakage fields. This paper describes a finite element method, including both iron saturation and eddy current reaction, to calculate the losses induced in the stator by these fields. The calculations compare favourably with loss densities measured within the stator core of a full size machine. Axial flux densities calculated by the method also show good agreement with flux densities measured on open and short circuit and at full load leading power factor whilst the machine was in service.