The rotating field method applied to damper loss calculation in large hydrogenerators

In this paper, we discuss key aspects of analytical rotating field models that can be used to estimate the damper losses in large hydrogenerators during steady load conditions. Model features of particular importance, like the saturation permeance and the structure of the damper circuit are described in greater detail. Damper currents extracted from the analytic model are found to be in good agreement with currents obtained from coupled field-circuit 2-D finite element calculations. The applicability of the model for damper current prediction during steady unbalanced load conditions is also demonstrated.