风力发电机组偏航系统误差与控制策略研究

发布时间：2018-05-22 15:08

本文选题：风力发电机组 + 偏航误差　；参考：《华北电力大学(北京)》2017年博士论文

【摘要】：现代大型风力发电机组所处的三维风场中存在风剪切和塔影效应,风轮捕获的气动载荷和功率都因之包含波动分量,致使机组振动、功率波动等问题突出;同时,自然界的风随机性强,风速和风向变化频繁,风电机组偏航系统经常需要频繁启停以进行迎风控制,即便如此,偏航误差仍不能被很好的消除,机组在绝大多数情况下处于偏航状态下运行。基于上述工程实际问题,本文以大型风力发电机组为研究对象,首先开展了基于风剪切和塔影效应的等效风速建模及其空间分布研究;然后基于等效风速分布模型和偏航误差模型,进一步研究了偏航误差对风力发电机组运行特性的影响;最后以偏航误差对机组运行特性影响的阶段性差异为判据,提出了阶段性优化偏航控制策略的改进方法。论文采用MATLAB仿真分析与风电场机组SCADA实际运行数据对比验证的方法对课题内容进行了深入研究。主要研究工作及取得的成果如下:现代风力发电机组正朝着大型化的趋势快速发展,风剪切和塔影效应对机组的影响愈发显著,风剪切和塔影效应对空间风速的影响使得风速在风轮扫略面上处处不同。针对这一问题,通过对风剪切、塔影效应以及两者共同影响下的风速扰动分量Wws,Wts和W+进行深入研究,提出了具有普适性的n-叶片风力发电机组等效风速分布模型,并推导了等效风速变换因数W_(eq)的数学描述。采用MATLAB数值模拟了等效风速的空间分布情况,并分析了2-叶片风轮、3-叶片风轮和4-叶片风轮的等效风速空间分布特点。以主流机型——3-叶片风电机组为例,研究了风机相关参数(R、H、A、x以及α和n等)对等效风速变换因数W_(eq)的影响规律,研究结果表明这些参数对等效风速的影响各不相同。通过推导并求解3-叶片风力发电机组风轮扫略面内的等效风速模型,结合风机特性模型和偏航误差模型,研究了在不同风速、不同控制阶段下偏航误差对机组运行特性的影响。提出并推导了考虑偏航误差的风轮气动转矩系数Tc、风轮转速系数Sc和机组功率系数Pc的数学模型。通过MATLAB进行了仿真计算,并与风场机组实际运行数据进行了对比验证。研究结果表明风机运行特性对偏航误差的响应随风速及机组控制阶段的不同而出现明显差异。以某风场2MW风力发电机组为研究和测试对像,首先描述和分析了目标机组的SCADA运行数据,进行了偏航系统性能分析,包括偏航过程分析、偏航误差的分布特性和偏航动作的随机特性分析,发现当前偏航控制策略的不足。然后针对偏航误差在不同风速、不同控制阶段对机组运行特性的不同影响规律,结合偏航误差的概率分布特性及其与风速变化的关系,提出了分段优化偏航控制策略的思想和方法,给出了控制流程。最后对实验机组进行了偏航控制参数优化和测试,通过机组SCADA运行数据对比分析,验证了本文所提偏航控制策略优化方法的有效性。本文的研究成果可为全面了解风轮扫略面上等效风速的空间分布特点以及深入研究偏航状态下的风机运行特性提供有益参考,同时也可为偏航控制策略阶段性优化、机组运行稳定性分析和风能利用率提升等方面提供技术支持和理论依据。
[Abstract]:There are wind shear and tower shadow effects in the three dimensional wind field of modern large wind turbines. The aerodynamic load and power of the wind wheel are caused by the wave component, which causes the vibration of the unit and the power fluctuation. At the same time, the wind randomness of the natural wind is strong, the wind speed and the wind change frequently, and the wind turbine yaw system often needs frequency. Even if so, the yaw error can not be eliminated well, and the unit is in most cases in the yaw condition. Based on the practical problems mentioned above, this paper takes the large wind turbine as the research object, first develops the equivalent wind speed modeling based on the wind shear and the tower shadow effect and its space. Secondly, based on the equivalent wind velocity distribution model and the yaw error model, the effect of yaw error on the operating characteristics of the wind turbine is further studied. Finally, the phase difference of the effect of yaw error on the operating characteristics of the unit is taken as the criterion, and an improved method for the phased optimization of the yaw control strategy is proposed. The thesis adopts the MATLAB The main research work and the results are as follows: the modern wind turbine is developing rapidly towards large scale, the wind shear and the tower shadow effect on the unit are becoming more and more significant, wind shear and tower shadow effect, the main research work and the results are as follows. The influence of the wind speed on the wind speed is different. For this problem, the equivalent wind velocity distribution model of the n- blade wind turbine is put forward by the wind shear, the tower shadow effect and the wind speed disturbance component Wws, Wts and W+. The equivalent wind velocity distribution model is proposed and the equivalent wind is derived. The mathematical description of the speed transformation factor W_ (EQ) is used to simulate the spatial distribution of the equivalent wind speed by using the MATLAB numerical simulation, and the spatial distribution characteristics of the equivalent wind speed of the 2- blade wind wheel, the 3- blade wind wheel and the 4- blade wind wheel are analyzed. The main model, 3- blade wind turbine, is taken as an example to study the equivalent parameters of the fan (R, H, A, x, and N and so on). The influence of wind speed change factor W_ (EQ) shows that the influence of these parameters on the equivalent wind speed is different. By deriving and solving the equivalent wind speed model in the windwheel sweep surface of the 3- blade wind turbine, combining the fan characteristic model and the yaw error model, the yaw error under different wind speeds and different control stages is studied. The mathematical model of the aerodynamic torque coefficient Tc, the speed coefficient Sc of the wind wheel and the power coefficient Pc of the unit, which consider the deviation of the yaw error, is presented and deduced. The simulation calculation is carried out through MATLAB, and the comparison with the actual operating data of the wind turbine unit shows that the operating characteristics of the fan are on the yaw error. The response of 2MW wind turbine in a wind field is studied and tested. First, the SCADA operation data of the target unit are described and analyzed, and the performance analysis of the yaw system is carried out, including the analysis of the yaw process, the distribution of deviation error and the random characteristics of the yaw action. In view of the deficiency of the current yaw control strategy, the different influence laws of the yaw error on the operating characteristics of the unit at different wind speeds and different control stages, and the relationship between the probability distribution characteristics of the yaw error and the change of wind speed are proposed, and the thought and method of the segmented optimization of the deviation control strategy are put forward, and the control flow is given. In the end, the parameters of the yaw control parameters are optimized and tested. Through the comparison and analysis of the operating data of the unit SCADA, the effectiveness of the optimization method for the yaw control strategy proposed in this paper is verified. The results of this paper can fully understand the space distribution characteristics of the equivalent wind speed on the swept surface of the wind wheel and further study the yaw state. It provides a useful reference for the operating characteristics of the fan, and also provides technical support and theoretical basis for the phased optimization of the yaw control strategy, the analysis of the stability of the unit operation and the improvement of the utilization rate of wind energy.
【学位授予单位】：华北电力大学(北京)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TM315

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