Performance Degradation And State Assessment Consideration The Working Condition Of Wind Power Gearbox

Gearbox is one of the key components of large doubly-fed wind turbine; its performance directly determines the performance of wind turbine. The working environment of wind turbine is severe; the gearbox sustains highly dynamic load and fatigue cycle under random wind,accompanying intense heat and extreme temperature difference, so it has the highest failure ratio in wind turbine. Therefore, research on performance degradation process and state assessment of gearbox considering working condition has important theoretical significance in predicting the trend of the wind turbine running state, making wind farm maintenance plan, and improving the wind turbine working reliability.This paper takes gearbox as the research object and studies its performance degradation and state assessment under the influence of working conditions(wind speed, temperature). The detailed research contents are listed as:1、The Hidden Markov Model(HMM) is applied to the gearbox in the study of the performance degradation, and the recognition framework of different degradation degrees is set up. Then, using wind machine simulation experiment platform to simulate different failure types and different extent of gearbox which verifies the validity of the model.Finally,the model is applied to performance degradation assessment of the gearbox of #1 wind turbine in Shanghai Chongming wind farm.2、A failure rate model of gearbox considering working conditions is set up using the markov process. Working conditions which focus on the weather(wind speed, temperature) could be obtained by the IEEE three state of weather model based on weighted average method. This model canpredict fault ratio in the future in the case of known current aging rate and future working condition changes of gearbox.3、The fuzzy comprehensive evaluation method is used to build state assessment model of wind turbine gearbox. The current life and fault hazard degree of gearbox are taken as a health evaluation index because the same fault causes different damage in different periods. Finally,through the calculation and analysis of monitoring data in the actual wind farm, the results based on assessment model which includes health evaluation indicators are verified to be much more accurate.