Fault Diagnosis of Wind Turbine Gearboxes using Enhanced Tacholess Order Tracking
Health monitoring of wind turbines is crucial to support their sustainability and economic operation. Gearbox
failures contribute significantly to the cost of wind turbine maintenance. These failures are typically monitored by vibration
sensors attached to external housing. Non-stationary vibration is induced by the variable-speed operation of the wind turbine.
In this paper, a new technique is introduced to enable the extraction of a speed reference from the vibration signal, which can
be utilized to remove speed fluctuations and diagnose faults in the gearbox. High speed variations of the shaft, i.e., tacho
signal, have been extracted from the vibration signal of an accelerometer mounted on the casing of the gearbox. The epicyclic
mesh frequency has been used to construct the speed reference by an enhanced order tracking technique comprising
auto-adjustable phase demodulation (APD). APDis aimed at improving fault detection efficiency by accommodating
highspeed fluctuations. The effectiveness of the proposed APD performance has been successfully demonstrated by using
vibration measurements from commercial in-service wind turbines.
Index Terms - Computed order tracking, Phase demodulation, Planetary gearbox, Non-stationary vibration