Flux density curves variations using an FEM model for turbo-generators diagnostics

Flux probe is an on-line tool widely installed in large turbogenerators, used to detect shorted turns in the rotor winding. As the measures of the airgap flux are quite easy to perform, it is more complicated to analyze and give diagnostics. In order to help the operator to detect defects with the variations of the flux density curves, a complementary approach has been realized with FEM simulations. By simulating electrical (shorted turn in the rotor winding) and mechanical defect (rotor eccentricity), and comparing their signature with the healthy machine or with some non modified part of the curves, it is possible to determine the type, the severity, and even the location of the defect.