基于多视角属性散射中心的风电机动态叶片雷达回波模拟

Radar Echo Simulation of Dynamic Wind Turbine Blade Based on Multi View Attribute Scattering Center

模拟高保真的动态风电机叶片雷达回波并提取其多普勒特征,是解决风电场对雷达台站无源干扰的关键问题。针对现有算法均无法准确且实时模拟动态叶片回波的问题,突破采用单一视角的静态散射中心模拟叶片回波的传统思路,将雷达视线下叶片整个旋转周期大转角划分为多个子视角,提出一种基于多视角属性散射中心的动态风电机叶片雷达回波模拟算法。考虑叶片动态旋转中叶片空间姿态对散射中心参量的变化影响,引入属性散射中心模型,采用正交匹配追踪的贪婪算法,提取各雷达视角下动态叶片的属性散射中心;并建立散射中心与叶片运动特征在时间上的对应关系,重构出叶片旋转一周的散射电场,利用短时傅里叶变换,最终模拟出动态叶片的回波。以金风82/1500型风电机叶片为算例,与传统回波模拟方法以及实验测量得到的结果进行对比,结果表明,所提算法较散射中心的积分算法在精度上提高了34.7%,实现了动态叶片回波的实时模拟。

The use of high-fidelity radar echo simulation of dynamic wind turbine blades to analyze the Doppler characteristics is the key issue to decrease the reradiation interference from wind farms on radar stations. Aiming at the problem that none of the existing algorithms could accurately simulate dynamic blade radar echo in real time, the traditional idea of using static scattering center under single view to simulate blade echo is broken. Thus, we proposed a dynamic wind turbine blade radar echo simulation method based on multi-view attribute scattering centers, with the large rotation angle of blade in radar line-sight dividing into multiple sub views. Since the blade’s spatial attitude had an effect on the scattering center’s parameters, the attribute scattering center model and the greedy algorithm of orthogonal matching pursuit were used, in order to extract the scattering center of dynamic blade under each radar view. Therefore, the timecorrespondence between the scattering center and the blade motion characteristics were established, and then the scattering electric field data of one rotation was reconstructed. Finally, the real-time simulation of dynamic blade echo was realized by the short-time Fourier transform. Taking the GW82-1500 wind turbine blade as an example, the simulation results between the experiment and the traditional algorithm and the proposed algorithm were compared. It shows that the proposed algorithm is 34.7% more accurate than the integral algorithm on scattering center, and especially, the real-time simulation of the dynamic blade echo is realized.