How Has Reliability Of Technology Developed Through Time?

摘要

This study attempts to obtain more detailed knowledge on failures of wind turbines (WTs), making use of the German '250 MW Wind' test programme database. Specific objectives are to show the reliability of some major components and to analyse how their design has advanced through time, what the main problems are, and which technologies have proven to work. Within the programme, reports on operation and maintenance (O&M) measures are being analysed regarding wind turbine type, size, and technologies used. This paper presents a comparison of component reliability through time, with respect to their technology. The results show significant differences in reliability for certain sub-components depending on size of the WT and especially on type of power control. I.e. induction generators are twice as reliable as synchronous generators. The study includes also reliability of other components that are affected or added due to the use of the components being analyzed. In general, the main results show that failure rates of wind turbine decrease with time. Most of the data present a short period of 'early failures' and later a long period of 'random failures'. However, this is not the case for the mega-watt class: as technology is introduced into the market, wind turbines present a longer 'early failure' behaviour, which has not yet become stable. Furthermore it gets obvious that large turbines, which should be the basis for future offshore WT technology, show a significantly higher amount of annual fault frequencies.