Comparative Investigation of Three Diagnostic Methods Applied to Direct-Drive Permanent Magnet Machines Suffering from Demagnetization

Abstract

Direct-drive permanent magnet machines are ideal candidates for remote renewable applications, due to their independence from gearboxes and minimization of maintenance needs. However, faults may still appear in the generator of such a machine and affect its operation and production. Not only can demagnetization cause a catastrophic breakdown if left unchecked, but it also directly impacts the output quality of generators. As such, demagnetization is a topic of great interest. This paper investigated the sensitivity of three diagnostic methods—current signature analysis (CSA), Park’s vector approach (PVA), and extended Park’s vector approach (EPVA)—for demagnetization fault detection on a coreless permanent magnet generator.

Diagnostics of Interior PM Machine Rotor Faults Based on EMF Harmonics

“…They effectively applied continuous wavelet transform (CWT) and discrete wavelet transform (DWT) methods to detect and discriminate demagnetization faults in PMSM motors under nonstationary conditions. The next article [21] focuses on the diagnostic techniques for identifying demagnetization faults in direct-drive permanent magnet machines. They compare the efficacy of three different methods, Current Signature Analysis (CSA), Park's Vector Approach (PVA), and Extended Park's Vector Approach (EPVA), in detecting these faults.…”