风向变化速度对风力机功率及转速的影响

为了探索风向变化时风力机输出功率及转速的变化情况,以某S翼型三叶片水平轴风力机为研究对象,利用旋转平台模拟风向匀速变化过程,采用IEC61400中规定的极端风向角变化速度5°/s为上限,每间隔1°/s选取1个风向变化速度,即选取1,2,3,4和5°/s这5个风向变化速度,研究不同风向变化速度下风力机输出功率、转速的变化规律.结果表明:风力机在不同风向变化速度下其输出功率与转速总体都呈现波动下降趋势,同一风速下风向变化速度越大,下降速率越快,但在其风向变化过程中对应的下降幅值越小;在风向变化开始与结束时都存在迟滞现象,风向变化开始时风力机输出功率出现小幅度上升,并持续波动3 s左右后才会开始下降;风向变化结束后,风力机需要继续运行一段时间后输出功率与转速才会达到稳定值,风向变化速度越大,该迟滞时间越长,初始尖速比越大,最终稳定后数值越大.

Effect of wind direction changing speed on power and speed of wind turbine

In order to explore the change of wind turbine output power when the wind direction changes, an S-airfoil three blade horizontal axis wind turbine was taken as the research object. The rotating platform was used to simulate the process of uniform change of wind direction. The upper limit is the speed of extreme wind direction angle change of 5 °/s specified in IEC-61400. One wind direction change speed was selected every 1°/s, that is, five wind direction changes were selected as wind speed, i.e. 1, 2, 3, 4 and 5 °/s, to study the variation of wind turbine output power and speed under different wind speeds. The results show that the output power and speed of the wind turbine show a fluctuating downward trend under different wind speeds. The results show that the output power and speed of the wind turbine fluctuate and decline under different wind speeds, the greater the wind direction speed changes at the same wind speed, the faster the decline rate, but the lower the corresponding decline amplitude in the process of wind direction change; there is a hysteresis phenomenon at the beginning and end of wind direction change, and the output power of the wind turbine has a small amplitude at the beginning of wind direction change after the wind direction changes, the output power and speed of the wind turbine need to continue to run for a period of time to reach a stable value. The greater the speed of wind direction changes, the longer the delay time, the greater the initial tip speed ratio, and the greater the final stable value.