Electromagnetic Analysis of Double-Rotor Direct-Drive Permanent Magnet Generators Under Eccentricity Faults

Permanent Magnet Synchronous Generators (PMSGs) have acquired a pivotal role in recent years, owing to their high-power density, high efficiency, and ability to operate in direct-drive configurations. Despite these advantages, such machines are susceptible to mechanical faults, particularly airgap eccentricity, with axial flux topologies being more vulnerable due to their high ratio of axial to radial length. Given the rapidly increasing deployment rates of these generators, this paper focuses on the electromagnetic analysis of a coreless axial flux dual-rotor direct-drive PMSG, with the analysis focusing on eccentricity faults. Static (SE) and dynamic (DE) eccentricities are investigated under a specific load condition using 3D finite element analysis (FEA) models. For the investigation of the fault scenarios, this work utilizes traditional signature analysis methods, namely Current Fast Fourier Transform (FFT), Voltage FFT, and Electromagnetic Torque Analysis.