Physics-Based Gearbox Failure Model for Multi-MW Offshore Wind Turbines

Abstract

This study proposes an analytical methodology to assess the risk to the operation of an offshore wind turbine in order to identify critical assemblies. The gearbox is one of the critical assemblies regarding maintenance costs and downtime. Failure investigation shows that the high speed shaft bearings are one of the gearbox components with a higher probability of fatigue damage. A physics-based model is developed to calculate the accumulated damage and to estimate the remaining useful life. The model is created for a 3 stage gearbox with two planetary and one parallel helical gear. This paper summarises the methodology and results of a damage accumulation calculation under a load spectrum derived from 1 year of SCADA data. The final results are consistent with the damage levels found in the failure investigation.

A review of failure prognostics for predictive maintenance of offshore wind turbines

“…S-N curve is a plot that describes the relationship between stress (S) and the number of cycles to failures (N). S-N curve can be directly used to calculate the RUL [25,26] or with Miner´s rule to forecast the lifetime of bending gear tooth root, high speed shaft bearings (HSSB), and blades [27][28][29][30]. The number of stress cycles can be counted by the rainflow counting algorithm.…”