Instantaneous mesh load factor (K_γ) measurements in a wind turbine gearbox using fiber-optic strain sensors

Journal Article · 01 June 2024 · Journal of Physics. Conference Series

DOI: https://doi.org/10.1088/1742-6596/2767/4/042022 · OSTI ID:2404292

Gutierrez-Santiago, Unai ^[1]; Keller, Jonathan ^[2]; Fernández-Sisón, Alfredo ^[3]; Polinder, Henk ^[4]; Van Wingerden, Jan-Willem ^[4]

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1. Delft Univ. of Technology (Netherlands); Siemens Gamesa Renewable Energy, Zamudio (Spain)
2. National Renewable Energy Laboratory (NREL), Golden, CO (United States)
3. Siemens Gamesa Renewable Energy, Zamudio (Spain)
4. Delft Univ. of Technology (Netherlands)

The mesh load factor, K_γ, describes how loads are shared between planet gears and has become one of the key design challenges in modern wind turbine gearboxes. Planet load sharing directly impacts tooth root stresses, a critical driver of torque density and gearbox reliability. Experimental evaluation of K_γ is typically performed from sun gear tooth root strain gauge measurements, which are complex. Furthermore, such measurements can only provide an average value of load sharing. The present study describes an alternative method to evaluate the mesh load factor in wind turbine gearboxes based on fiber-optic strain sensors installed on the outer surface of the fixed ring gear. We present the results of an extensive measurement campaign to evaluate this novel sensing solution installed on the input planetary stage of a 2-MW wind turbine gearbox at the National Renewable Energy Laboratory's Flatirons Campus (Colorado, USA). The number of strain sensors on the ring gear was selected as an integer multiple of the number of planets, which has enabled an instantaneous evaluation of the mesh load factor. The effect of operating conditions on the planet load-sharing behavior of the gearbox has been investigated. The mesh load factor measured for operating conditions close to rated was below 1.05, well below IEC 61400-4 standard requirements.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Wind Energy Technologies Office
• Grant/Contract Number: AC36-08GO28308
• OSTI ID: 2404292
• Report Number(s): NREL/JA--5000-89037; MainId:89816; UUID:d7848d86-809f-44e4-92e9-0d2a1b54bba5; MainAdminId:72219
• Journal Information: Journal of Physics. Conference Series, Journal Name: Journal of Physics. Conference Series Journal Issue: 4 Vol. 2767; ISSN 1742-6588
• Publisher: IOP PublishingCopyright Statement
• Country of Publication: United States
• Language: English