Evaluation of damage mechanics of industrial wind turbine gearboxes

In recent years, global wind power capacity has grown steadily at an annual rate of around 20%. This has led to wind energy becoming the most important renewable energy source on a global scale, with the total installed capacity reaching 430 GW. However, the strong growth of offshore wind power has been somewhat inhibited due to a number of operational challenges that are yet to be addressed in full. The most important of these challenges appears to be the reliability of the wind turbine gearbox (WTG). WTGs are currently unable to survive their anticipated design lifetime of 20-25 years. Most of them hardly reach a useful operational lifetime of more than seven years without serious refurbishment or replacement and, for offshore wind turbines, failures have been reported as early as within one to two years. In this paper, the damage mechanisms influencing WTGs supported by finite element analysis have been considered and presented in the context of condition monitoring diagnosis and prognosis.