Summary
Main bearing failures in induction and DFIG wind turbine generator powertrains were initially identified as a concern around 2011 by National Laboratory of the Rockies (NLR formerly
Read more Read lessNREL) in reliability statistics. Since 2019, field investigations of both doubly-fed induction generators (DFIG) and full-inverter induction wind turbines have revealed pervasive circulating currents, composed of both fundamental and higher order harmonic, inter-harmonic, and supraharmonic components, flowing through key drivetrain loops. These loops include the shaftbearing interface, gearbox housing and components, generator to structure, electronics and tower base. Peak shaft currents exceeding 150 Amps-peak have been detected at these frequencies with commercial and specialty electrical and current signature analysis technologies. These currents drive electrical discharge erosion in rolling elements and gears and initiate electrical degradation in insulation systems, leading to 60% of main bearing failures and half of generator insulation faults in a study sample of 200 turbines. To translate spectral measurements into actionable maintenance and design decisions, this paper introduces the
Relative Harm Index (RHI), a nondimensional metric that correlates current amplitude and frequency to damage potential.
Additional informations
| Publication type | Session Materials |
|---|---|
| Reference | A1_10180_2026 |
| Publication year | |
| Publisher | CIGRE |
| Country | United States of America |
| Study committees | |
| File size | 2 MB |
| Price for non member | 30 € |
| Price for member | 30 € |
Authors
PENROSE Howard W. - MotorDoc LLC, United States of America
Keywords
