考虑实际风速时空分布的风力发电机组故障特征分析与机电联合故障识别研究

The traditional wind driven generator fault analysis and diagnosis methods mainly focuses on the noumenon of generator, the aerodynamic load will fluctuate due to the difference of temperal-spatial distribution of wind speed on the rotor swept area, and the influence of the aerodynamic load fluctuation on fault feature is rarely considered. Therefore, wind turbine generator system faults feature analysis and mechanical-electrical joint fault identification study considering the temperal-spatial distribution of actual wind speed are proposed in this research project, the research content mainly includes: (1) Fully considering the factors such as turbulence, wind shear, tower shadow effect and yaw error, this research project will establish a three-dimensional time varying flow field model on the rotor swept area, and analyze the temperal-spatial distribution characteristics of the actual wind speed; (2) Research on the electrical and the mechanical vibration characteristics of electrical fault including stator and rotor winding inter-turn short circuit fault considering the actual wind speed spatial and temporal distribution characteristics;(3) Research on the mechanical vibration and the electrical characteristics of mechanical fault including generator air-gap eccentric and blade imbalance fault;(4) Develop a wind turbine generator system fault simulation experiment platform considering the actual wind speed spatial and temporal distribution characteristics, then set up and test the mechanical-electric joint diagnosis model based on the comprehensive consideration of both electrical and mechanical vibration characteristics of the fault. The study of this project can fully understand the actual operation of the wind turbine in the complex and changeable natural environment, and provide a theoretical support for the optimization of the control strategy, operation and maintenance.

传统的风力发电机故障分析及诊断方法主要侧重分析发电机本体，极少考虑叶轮扫掠面上风速时间和空间分布差异引起的气动载荷波动对故障特征的影响。因此本课题提出并研究考虑实际风速时空分布的风力发电机故障特征分析，主要研究内容包括：（1）全面考虑湍流、风剪切、塔影效应及偏航误差等因素，建立整个叶轮扫掠面上风速三维时变流场模型，探索实际风速时空分布特点；（2）研究考虑实际风速时空分布特点时风力发电机定、转子绕组短路等电气故障的电气和机械振动特征；（3）研究考虑实际风速时空分布特点时风力发电机气隙偏心、叶轮不平衡等机械故障的机械振动和电气特征；（4）研制考虑实际风速时空分布特点的风力发电机组故障模拟实验系统，在综合考虑故障的电气和振动特征的基础上,建立并验证故障的机-电联合诊断模型。本项目研究可全面了解风机在复杂多变自然环境中的实际运行和发电状态，为风电场机组控制策略、运行维护方案等的优化提供理论支撑。

传统的风力发电机故障分析及诊断方法主要侧重分析发电机本体，极少考虑叶轮扫掠面上风速时间和空间分布差异引起的气动载荷波动对故障特征的影响。本课题提出并研究了考虑实际风速时空分布的风力发电机故障特征分析，取得的主要成果：.（1）基于风剪切和塔影效应数学模型建立了具有普适性的n-叶片风力发电机组等效风速模型，提出并推导了等效风速变换因数Weq的数学描述。研究得到了叶片数目n、风轮半径R、塔筒高度H、塔筒半径a、悬垂距离x、风剪切指数α等风机参数对等效风速变换因数的影响，以及这些风机参数对功率波动的频率、幅值、波长、波动区域等特性影响规律，和对功率损失的影响规律。.（2）研制了双馈风力发电机故障模拟机组，主要由驱动电机、齿轮箱、双馈发电机、控制柜、负载箱、性能测试分析硬件平台等组成，其中驱动电机采用伺服电机驱动，实现风速时空分布下的转速波动。同时双馈发电机能够模拟定转子绕组匝间短路、气隙动偏心、气隙静偏心、气隙斜偏心、气隙轴向串动、绕组不对称、负载不平衡等单故障和复合故障。.（3）考虑实际风速时空分布时，对风力发电机组叶轮不平衡故障、定转子绕组匝间短路故障和绕组不对称故障下电磁转矩、电磁功率、转子角速度、定转子电流/电压进行了解析推导、仿真分析和实验研究。给出了在考虑风速时空分布后，定子电流和转子电流/电压的新故障特征频率。同时也指出与电气信号基频幅值相比，风速时空分布引起的故障特征频率幅值相对较小，建议在实际故障诊断应用中注意前两阶调制频率(3P和6P)。最后综上分析分别提出了基于定转子电流特征的叶轮不平衡、定转子绕组匝间短路和绕组不对称故障诊断方法等。