| This paper aims at failure problems occurred in operational process of a large of domestic doubly-fed wind turbines and carry out researches on failure modes, mechanisms, causes and diagnosis method on different levels. By statistical analysis of large-scale field failure data, the failure modes and distribution of main components in wind turbines can be formed. The failure modes and failure causes of main components in wind turbines can be obtained by using fault tree analysis method. Taking envelopment analysis on vibrations of main components like gears and bearings, than extract failure feature information of gear and bearing from vibration signals to achieve fault diagnosis. Such researches can improve operation and maintenance levels of wind turbines and provide technical supports for technological capabilities. The main research contents in this paper are as follow:(1) Statistical analysis on failure modes of large-scale equipment of wind farms: Taken domestic region-scale wind power companies as research objects, collect the failure data of equipment on wind farms since they were put into operation, get the failure rates and downtime distributions of main components in wind turbines, and form failure modes in a component level. The research can provide references and technical supports for carrying out a reasonable operation and maintenance management on wind turbines.(2) Fault tree analysis on typical failure of key components in wind turbines: Applying fault tree analysis method on failure analysis of wind turbine equipment. Based on statistical analysis of failure data on wind farms, the failure types, failure frequency, failure modes and failure severities of parts are analyzed according to the failure statistic data recorded by corresponding wind power company departments. Then, confirm the typical failure types, failure mechanisms, and developing modes of main components, and establish the fault tree of wind turbines.(3) An envelopment analysis method on gear and bearing faults of wind turbine: envelopment analysis based on Hilbert transform and envelopment analysis based on broad detection and filter method are applied to analyze fault features of gear and bearing of wind turbine. Both methods are studied in simulation research. According to the analysis on vibration mechanism of gear and bearing faults, the methods are applied to practical signal to prove good practical effect of envelopment analysis.(4) Engineering construction overseeing technology for wind farm:On the basis of management experience and technical documents of wind plant constructing, several suggestions are proposed to improve engineering construction overseeing technology through analyzing and summarizing construction overseeing regulations of internal large-scale wind farm. This part is presented as appendix. |
