Detection of Interturn Short-Circuits in the Rotor Winding of a Hydrogenerator

Abstract

A method of detecting interturn short-circuits in the rotor winding by analyzing the magnetic field in the stator-to-rotor gap of a hydrogenerator is discussed. For the purpose of theoretical justification, the magnetic field is analyzed numerically using the finite-element method in the cases of presence and absence of short-circuited turns in the rotor winding. The numerical results are compared with experimental data for a 640 MW hydrogenerator.