Wind turbine gearbox fault diagnosis based on symmetrical components and frequency domain

Abstract

The region of Adrar in Algeria is the windiest in the country; it is for this reason the electricity and gas company “Sonelgaz” has placed a wind farm of about 10 MW. Since it is a Saharan region, the wind is sandy, rich in silica that can damage the teeth of wind gearbox. The present work proposes a method which can make an early diagnosis of the broken tooth and its location in the gearbox, before the general breakdown. The modeling of defaults inside the turbine gearbox by symmetrical components technique is proposed successfully and for the first time in the field of diagnostics (usually this technique is used in the power grid lines short circuits analysis), associated with frequency response analysis. In addition, as it is impossible to install sensors at different parts, the increase in temperature and vibration inside the gearbox due to default, a sensor-less fault diagnosis based on the analysis of power signal generated by the wind turbine is presented and detailed. Furthermore, the peculiarity of this work is the modeling of unbalance forces caused by teeth failure on both the slow shaft and the fast shaft of the gearbox, which has never been considered before. It has been proven that this proposal allows a precise location of the broken tooth and the concerned gear inside the gearbox.