Analysis and detection of turbo-generator stator turn-to-turn fault with multi-loop method

Turn-to-turn fault in the synchronous generator stator winding has been considered the most challenging one since the other types of stator winding related failures are usually the consequence of turn faults. In this paper we studied the turbo-generator in no load and load conditions and utilized the multi-loop method which can consider the asymmetric problem to detect the turn-to-turn fault of stator winding. The multi-loop model of the turbo-generator was established and the permeance analysis was used to calculate parameters of the model. The fault detection accuracy was improved by using the decomposition of wavelet analysis to detect the even harmonics in field current signal. The simulation results show that the stator turn-to-turn fault can be unambiguously detected from the field current signal.