Static calibration of microelectromechanical systems (MEMS) accelerometers for in-situwind turbine blade condition monitoring

Abstract

As wind turbines get larger, operation and maintenance costs can be expected to rise unless reliability is improved. One important strategy for achieving this is through condition monitoring. Condition monitoring is a preventive type of maintenance based on the actual health of the wind turbine under observation. Its use allows an operational strategy to be employed based on information measured and provided by a condition monitoring system. This paper outlines the procedure for least square static calibration of inexpensiveMicroelectromechanical Systems accelerometers identified and instrumented for detecting and measuring changes in natural frequency (key information useful for condition monitoring) of a 4.5 m long wind turbine blade. The calibration procedure converts the local accelerometer coordinates to the global coordinate system of the blade and eliminates the accelerometer offsets from results. The objective is to enable easier comparison of results obtained from multiple accelerometers positioned arbitrarily along the blade, independent of the accelerometer orientation on the usually curved wind turbine blade surface.