Analysis of faults in synchronous generators are so important to protect the generators and the power systems. In this paper, double line-to-ground fault analysis in unloaded synchronous generator is presented. Apart from the similar studies in the literature, the synchronous generator is considered in unbalanced operation in this study. For this aim, new sequence circuits are obtained for synchronous generator. Thus, new equivalent circuit for short circuit consisting of the obtained sequence circuits is obtained to analyze short circuit of double line-to-ground fault in unbalanced and unloaded synchronous generator. The proposed short circuit model is applied to a sample fault system and the obtained results are given.

Keywords - double line-to-ground fault, short circuit, synchronous generator, symmetrical components, sequence circuits

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