Fault diagnostics of wind turbine electric pitch systems using sensor fusion approach

Abstract

Failures in wind turbine pitch systems can cause significant outages in offshore wind turbines due to the finite weather windows for maintenance. In a complex system such as the pitch system, a fault in the gearbox can contaminate the motor current signals and result in a misdiagnosis. This paper investigates a sensor fusion technique to reliably diagnose faults in pitch motors and multistage planetary gearboxes in pitch drives. A support vector machine classifier is used for fault diagnosis based on features extracted from motor currents and gearbox vibration signals. The approach is validated with three commonly occurring pitch drive faults, namely, the stator turns fault in the pitch motor, input shaft bearing and planet gear fault in the planetary gearbox. The developed diagnostic method is validated with artificially seeded faults in a laboratory setup of a scaled pitch drive.