Diagnosis and detection of dynamic eccentricity fault for permanent magnet transverse flux generator

The authors analyse no‐load and full‐load performance of a permanent magnet transverse flux generators (PMTFGs) in fully aligned condition as well as under different types of mechanical faults including static eccentricity (SE), dynamic eccentricity (DE), inclined rotor (IR) and run‐out (RO) faults. An analytical model is developed to calculate the air‐gap permeance. This permeance is used to estimate the flux density and back‐electromotive force in the healthy and faulty machine. Performance of the machine is predicted using the proposed analytical model and verified by comparing it with the results obtained using three‐dimensional time stepping finite element method. Finally, the spectra of stator current in the PMTFG under SE, DE, IR and OR faults are determined through which the amplitude of side‐band components with a specific frequency pattern is extracted. It can detect the eccentricity fault precisely, recognise its type and determines its severity.