过渡循环对风力机疲劳评估的影响及修正

Effects and correction of transition cycles on fatigue assessment of wind turbine

随着风力机的装机容量和尺寸的不断增大,其运行环境更为复杂,疲劳问题突出,需要准确预测风力机结构遭受的实际疲劳损伤。通过对1.5 MW风力机的塔底应变进行长期监测,研究了不同方法在处理雨流计数后残余数据点问题上的准确性。首先,通过采用不同的计算时窗,分析过渡循环对疲劳损伤的影响,选择的计算时窗越短,得到的疲劳损伤误差越大,当计算时窗为10 min时,误差达到了20.7%。然后,使用残波串联法处理残余数据点,此时选择不同的计算时窗得到的损伤值均与将监测时段内所有数据作为连续序列得到的结果相同,证明了该方法在处理雨流残余数据时的准确性。该成果为风力机结构疲劳损伤在线预测提供了解决方法,可以更加准确的得到构件的实时损伤。

With installed capacity and size of wind turbines continuing to increase,their operating environment becomes more complex,and fatigue problems are prominent.It is necessary to correctly predict actual fatigue damage suffered by wind turbine structure.Here,through long-term monitoring tower bottom strain of a 1.5 MW wind turbine,the correctness of different methods to deal with residual data points after rain-flow counting was studied.Firstly,by using different calculating time windows,effects of transition cycles on fatigue damage were analyzed.It was shown that the shorter the selected calculating time window,the larger the fatigue damage error obtained;when the length of calculating time window is 10 minutes,the error reaches 20.7%.Then,the residual wave series method was used to process residual data points.At this time,damage values obtained by selecting different calculating time windows were the same as the results obtained by taking all data within the monitoring period as continuous series to prove the correctness of this method in processing rain-flow residual data.the results showed that this achievement can provide a solving method for online prediction of fatigue damage of wind turbine structures,and more accurately obtain real-time damage of components.