Effect of saturation on rotational flux distribution in hydro generators

Uprating of hydro generators requires studies into the potential areas of failure like hotspots within the machine core. Rotational core losses cause localized heating of the core therefore understanding the distribution and behavior of rotational flux in the machine is key. This paper studies the distribution of rotational flux in a hydro generator as the core material is saturated. The percentage of rotational flux in the stator increases as the material is saturated especially for aspect ratios above 0.6. This can affect the loss distribution in the machine. Moreover experimental core loss data of non-sinusoidal flux densities in various parts of the machine at no load and full load operation are also presented.