Modeling and validation of losses due to unbalanced loading of stand-alone generators

The goal of this paper is to evaluate the possibility of deriving a simple lumped electrical model of the additional losses in stand-alone synchronous generators due to unbalanced loading. An in depth analysis will reveal that the additional loss due to unbalanced loading is partially dissipated in the rotor. Because analytical segregation of the individual loss components remains complex due to the skin effect in the rotor bars, Finite Element Modeling is used to accurately model the loss, inherently taking into account the skin effect. The results obtained by Finite Element Modeling are compared to practical measurements and are consequently used to evaluate the possibility of deriving lumped electrical models.