Abstract:Gear box is the main actuator for wind turbine unit and its state monitoring is essential for the safety operation of wind turbine unit. Because that wind turbine unit is greatly influenced by wind speed fluctuation, its revolving speed changes in real time, which increases the difficulty of gearbox state monitoring. Through analyzing the gear box vibration signals of two units for a certain wind power plant, this paper revealed the linear relationship between vibration signals and revolving speed. And after that, it proposes the solution of converting the vibration signals under arbitrary speed to rated speed, which effectively reduces the influence of revolving speed to vibration signals, improves the trend of monitoring indictors, and provides effective monitoring indictors for gear box state monitoring.

Keywords:wind turbine unit, gear box, condition monitoring, vibration signal, revolving speed