Stator core fault diagnosis for induction motors based on parameters adaptation

A novel on-line stator core fault diagnosis method for induction motors (IM) is proposed. This approach is based on an adaptive state observer; it is derived from the IM dynamic model considering stator iron losses. In this model the iron losses are represented by an equivalent iron loss resistance (R_Fe). Stator core fault causes important variations on iron losses and these variations are reflected on the R_Fe. Therefore the proposed adaptive state observer estimates R_Fe with the objective of diagnosing stator core fault. Simulation and experimental results for different fault severity conditions are showed. These results demonstrated the validity of the method. In addition, simulation results proved that the proposal is not sensitive to load torque variations.