Tranfer Path Research On Multiple Fault Vibration Signal Of Wind Turbine Gearbox

As wind energy is an important part of the new energy, the wind energy industry has developed rapidly to be a larger scale. But wind power equipment is in the extremely poor operating environment, which easily causes system failure. Wind turbine gearboxes are the key component of wind power equipment and have a significant influence on the health of the entire wind turbine. Therefore, the condition monitoring and fault diagnosis of wind turbine gearboxes is necessary to improve the reliability of wind turbines.Sensitive measuring point and transfer path analysis is the basis of the mechanical equipment condition monitoring and fault diagnosis and has been focused by researchers. Currently, wind turbine gearboxes mostly contain planetary transmission mechanism, whose several planet gears not only rotate around their own centers but also revolve around the center of the sun gear, and once planetary gears have faults, transfer paths of the fault vibration signals are time-variant, which has brought great challenges to fault diagnosis of wind turbine gearbox. So, the study on transfer paths of the fault vibration signals is particularly important. For the same fault, different measuring points cause different transfer paths of the fault vibration signals, and its different sensitivity to the fault vibration signals. Thus, the research on sensitive measuring points of vibration signal will help to extract fault features and reveal failure mechanism of wind turbine gearboxes, and have important theoretical significance and engineering application value.This paper firstly describes the transmission scheme of wind turbine gearboxes, the working principle, components and operating conditions, etc, and summarizes fault types of wind turbine gearboxes and determine the outer race spalling of the planet carrier bearing and the local spalling of a planetary gear to be the object of study, and analyzes the influence of structural characteristics of wind turbine gearbox on vibration signals. Secondly, vibration signal of such faults are acquired from five acceleration sensors arranged on the wind turbine gearbox housing. In order to better compare the sensitivity of each measuring point, the fault vibration signal is decomposed into high- and low-resonance components and redundant component using the adaptive RSSD. In the signal decomposition process, the quality factor and weighting coefficients simultaneously are optimized to obtain good decomposition effect. Then, the original signal and the high resonance component containing fault information are analyzed and evaluated according to the relative kurtosis index for determining the position where sensitive measuring points are located. Finally, to rank the importance of transfer paths of multiple fault vibration signals between the sensitive measuring point and fault points, this paper develops the method for calculating the contribution of transfer path based on the power flow, and analyzes the six transfer paths of multiple fault vibration signals of the wind power gearbox, and use the power flow finite element method to simulate and analyze the transfer paths of the fault vibration signals of the wind power gearbox. According to the proposed method, the total contribution of each transfer path is calculated and ranked to determine the main fault vibration signal transfer path.