High frequency resonance of AC machine windings, analyse of current and electromagnetic fields. Application to predictive maintenance
Résumé
The paper analyses the high frequency (HF) behaviour of an AC machine winding. The goal is to detect slight resonance frequency changes due to dielectric aging. The proposed monitoring system injects a low level HF voltage in the stator winding of the running machine and performs measurements on the corresponding current and external magnetic field. The analysis is carried out with an HF electrical equivalent circuit, which explains the choice of the frequency used by the monitoring system.