large wind turbines will require more cost-effective operations
based on optimised levels of Reliability, Availability, Maintainability
and Safety (RAMS).
Blanco [2] showed that the Operation and Maintenance (O&M)
costs can be 20%e30% of the total Level Cost of Electricity (LCOE)
over the project's lifetime. Although larger turbines may reduce the
O&M costs per unit power, the cost per failure increases due to the
combined cost associated with emergency corrective maintenance
and loss of production during downtime [3]. By employing a suitable
Condition Monitoring (CM) technique, many faults can be
detected and controlled under operational conditions. Early
detection of incipient faults prevents major component failures and
allows for the implementation of predictive repair strategies [4].
Therefore, appropriate actions can be planned in time to prevent
major failures which in the case of corrective maintenance