用于风力发电机偏航控制的激光测风系统设计与试验

为实现风力发电机迎风信息的精确测量,采用连续波相干探测技术,设计了针对风力发电机偏航控制需求的激光测风系统。该系统的扫描装置中由直驱电机带动15°顶角楔形镜旋转实现激光对大气的圆锥扫描,设置扫描一圈用时为15 s,每圈采样点数为30个,利用正弦拟合方法反演风力发电机前方的风场信息。将激光测风系统安装在深圳市气象观测梯度塔下,与塔上超声波风速仪进行了对比测风试验。经过数据分析,水平风速相关系数达0.98,标准差为0.22 m/s,风向相关系数达0.97,标准差为3.04°,表明所设计的激光测风系统性能优良,工作稳定可靠,能够为风力发电机提供精确风场参数,提高风能的利用效率。     

风力机功率控制器的研究

MPPT（Maxmin Power Point Tracking）控制方法在风力机功率控制器中处于核心地位,其控制策略的优劣影响整个系统的输出特性。本文构建了风力发电系统仿真模型,深入研究了风机输出特性,在此基础上对以往MPPT控制方法的改进提出自适应变步长控制策略,使其能够应用于小型风力发电系统中。     

PLC控制器在风电机组中的应用

结合750kW风力发电机组的控制要求,对风电机组PLC控制系统进行了分析,研究了PLC控制器的构成和风机运行控制方法,并对该系统的PLC控制系统的软件、硬件进行了设计.     

Innovative adaptive pitch control for small wind turbine fatigue load reduction

As a renewable source of energy, wind is widely used to produce electrical power. The progress of wind turbine technology can greatly benefit from the improvement of control algorithms. The pitch angle control of a horizontal axis wind turbine above the rated wind speed is a challenging issue related to the nonlinear aerodynamic behavior of blades. The linearization of aerodynamic model around nominal operating condition, as well as manufacturing deficiencies, result in unknown parameter uncertainties in a wind turbine model. Therefore, the performance of controller, which is designed based on the mathematical model, defects in practice. In the current paper, an adaptive self-tuning regulator (STR) configuration is proposed for the pitch control, so that the parameters of wind turbine model are constantly estimated and the controller gains are updated based on the assessed parameters. The STR structure consists of a recursive least square estimator and a proportional-integral-derivative (PID) controller with adjustable gains, which are determined by the pole placement method in a real-time routine. The robustness of the closed loop system is investigated by implementation of the control structure on an aero-servo-elastic wind turbine simulator. For the sake of comparison, a baseline gain scheduling PID controller, which is well-accepted for wind turbine pitch control, is designed. A comparison between the simulations of two controllers confirms a significant improvement in the closed-loop performance including less fluctuation of rotor speed and power besides minor fatigue loads on the blades and main-shaft.     

Adding feedforward blade pitch control to standard feedback controllers for load mitigation in wind turbines

Combined feedback/feedforward blade pitch control is compared to industry standard feedback control when simulated in realistic turbulent winds. The feedforward controllers are designed to reduce fatigue loads, increasing turbine lifetime and therefore reducing the cost of energy. Two feedforward designs are studied: collective-pitch model-inverse feedforward using a non-causal series expansion and individual-pitch gain-scheduled shaped compensator. The input to the feedforward controller is a measurement of incoming wind speed, which could potentially be provided by LIDAR. Three of the designs reduce structural loading compared to standard feedback control, without reducing power production.     

System design consideration for digital wheelchair controller

The design and implementation of a digital wheelchair controller system is presented in this paper. This novel model depicts an information flow between the driving commands and wheel speed. A command interpreter and two speed processing datapaths are proposed as functionally independent blocks for the controller. The control process consists of the following steps: command decoding, speed estimation, and speed serving. Through proper partitioning to concurrent blocks, the design complexity is reduced significantly. Block reconfiguration for field-programmable gate array rapid prototyping is also employed in this paper, and system fidelity and development efficiency are revealed through the experimental results     

Neural networks for wind turbine supervision

Wind energy converters are generally working under very variable conditions which require high maintenance costs. Therefore, it is important to supervise their behavior in order to provide an accurate and reliable forecasts of the energy production. The aim of this paper is to demonstrate a monitoring system for wind turbines which will result in a cost reduction of maintenance and an improvement of the cost/benefit ratio of wind energy. As it is very difficult to define the faulty behavior, we propose to use autoassociators networks in order to process the information which is available under operating conditions. These networks are used to detect any modification of the behaviour of the wind converter. This system complements the standard monitoring equipment of the wind energy converters to yield detailed on-line information on the state of the machines.     

对于风电场电气设备中风力发电机的运行维护的措施

风力发电机是实现风能、机械能与电能之间相互转化的机电设备,在风电场中风力发电机是十分重要的设备,长期使用过程中风力发电机很容易出现各种故障问题,对此必须要加强对各种故障的处理,提高风力发电机的运行效率.本文对风力发电机运行维护的相关策略进行分析和探讨.     

直驱永磁同步风机低电压穿越控制方法研究

本文给出了用于直驱永磁同步风力发电系统暂态分析的传动轴系的双质块模型和全功率变流器数学模型,分析了低电压故障下直驱永磁风力发电系统的暂态特性。提出了相应的变流器改进技术措施,利用PowerFactory/DIgSILENT仿真软件对所设计的LVRT改进控制方法进行仿真建模,并验证了其有效性。     

大型风电叶片动态摄影测量网络优化

在大型风电叶片动态摄影测量中,为了对相机的站位进行优化,采用一种变异操作改进型遗传算法作为摄影测量网络优化方法,通过光线束前方交会的误差传递建立测量误差模型,以空间坐标测量误差的标准差为网络优化的目标,同时根据被测风电叶片几何结构和实际环境确定了相应的约束条件进行仿真实验,得到了最优的相机站位。结果表明,在以叶片长度为40m的风机为被测物的仿真实验中,最优站位的空间坐标测量误差标准差为2.7mm;通过对叶片长度为3.5m的风机模型进行实测实验验证,最优站位的相对测量误差为0.009%,最大误差为0.617mm。该研究为风电叶片摄影测量的网络优化提供了参考。     

支持向量回归机在风电系统桨距角预测中的应用

为解决风力发电系统中随着风速的变化,桨距角也随之发生不确定变化的问题,运用支持向量回归机算法对桨距角预测和仿真检验,并可将预测误差达到最小.该方法主要包括支持向量机中的回归分析技术,针对有限样本情况得到现有信息下的最优解.应用结果表明,此算法精度高,泛化能力强,可提高整个变桨距系统的控制精度和效率.     

关于风电场风电机组中风力发电机的运行维护分析

本文通过风电机组中风力发电机的常见故障分析,针对故障诊断难点问题,优化风力发电机的运行维护环节,重点加强故障难点的维护工作,为风电场风电机组的运行维护提供新的思路.     

风力机叶片翼型改进方法的研究

以最大相对厚度较小的某风力机新翼型为研究对象,拟对其进行结构改进。利用FLUENT软件计算了该翼型吸力面和压力面上沿来流x方向的切应力,据此找到了吸力面边界层分离点,以此点开始对翼型吸力面沿后缘点进行适当加厚,并对修改前后的翼型进行了气动特性对比分析。结果表明：从翼型压力面边界层分离点到后缘点对翼型进行适当加厚处理,对其气动性能影响不大,却可改善风轮的结构动态特性,为满足工艺需求,在叶片实际加工中对后缘部分进行适当加厚处理是可行的。     

Experience with bicoherence of electrical power for conditionmonitoring of wind turbine blades

The authors explore the application of the normalised bispectrum or bicoherence to the problem of condition monitoring of wind turbine blades. Background information is provided on this type of condition monitoring, how it differs from more conventional condition monitoring of turbo machinery, and the motivation for selecting bicoherence. Bicoherence is defined and compared with the power spectral density. Complications in collecting suitable data, and estimating the bicoherence from that data are investigated; including the requirements of very long stationary data sets for consistent estimates, and computational difficulties in handling such large data sets. Bicoherence is then applied to electrical power output data obtained from a 45 kW wind turbine. The turbine is operated in three configurations to represent normal and fault conditions. A blade with less flapwise stiffness but identical outer dimensions to the matched set of blades was fitted to simulate a damaged blade. Comparison of the results from the power spectral density and bicoherence indicates how the bicoherence might be employed for condition monitoring purposes. Slices of the bicoherence with one frequency fixed at the rate of rotation show clear differences between the configurations and substantially reduce the computational effort required to calculate the estimate     

Control design for a two-bladed downwind teeterless damped free-yaw wind turbine

In this paper, a control architecture for a two-bladed downwind teeterless damped free-yaw wind turbine is developed. The wind turbine features a physical yaw damper which provides damping to the yawing motion of the rotor-nacelle assembly. Individual Pitch Control (IPC)¹ is employed to obtain yaw control so as to actively track the wind direction and to reduce the turbine loads. The objectives of both load and yaw control by IPC are conflicting and therefore two decoupling strategies are presented and compared in terms of controller design, stability, and turbine loads. The design of the different controllers and the physical yaw damping are coupled and have a large impact on the turbine loads. It is shown that the tuning of the controllers and the choice of the yaw damping value involve a tradeoff between blade and tower loads. All results have been obtained by high-fidelity simulations of the state-of-the-art 2-B Energy 2B6 wind turbine.     

Optimal /spl rho/-realisation for digital controller implementation with stability consideration

The stability robustness problem of a discrete-time feedback system, where the digital controller is implemented with finite word length, is investigated. Based on a polynomial operator approach a new sparse controller realisation, called /spl rho/-realisation, is derived. The problem of finding optimal /spl rho/-realisations is solved. A numerical example is given, which shows that the optimised structure outperforms the fully parametrised optimal realisation.     

简析风力发电机组的调试与排故措施

风力发电机组的调试以及故障排除对于系统的稳定运行有着积极的意义.必须结合风机生产车间的实际制造状况以及系统运行的状态,检查测试结果来进行设备的维护与检修.本文详细阐述了风力发电机组的故障种类以及产生恨因,并针对具体的原因采取合理的排除措施,以保证系统的稳定运行.     

Comparative analysis of maximum power point tracking controller for wind energy system

This paper proposes an adaptive maximum power point tracking (MPPT) control method to achieve the maximum power from the wind turbine (WT) power generation system. The MPPT control method has a vital role to find the maximum power point, and also compute the simulation results in both analysis such as offline using MATLAB/SIMULINK? and online using OPAL-RT simulator. The proposed adaptive perturb and observe (P&;O) algorithm provides better results using the OPAL-RT simulator compared to the P&;O method using MATLAB/SIMULINK?. The power generation through doubly fed induction generator (DFIG) WT system is becoming important day by day throughout the world. The simulation result by OPAL-RT simulator showed that the efficiency of WT-DFIG has been enhanced.     

风力发电机转速控制系统的建模与仿真

针对风力发电机非线性、随机性、扰动大等特点,设计基于带动量项的粒子群优化的支持向量机的风力发电机转速控制建模的新方法。利用支持向量机对小样本、高维度、非线性特性的映射能力,将风电系统的采样数据映射到高维的特征空间进行建模。支持向量机惩罚因子C和核参数σ的选择对建模效果影响较大,经验试凑的方法难以获得较好的参数,引入粒子群算法进行参数寻优。为了克服传统粒子群算法易陷入局部最优且收敛速度慢的缺陷,提出带动量项的改进粒子群算法寻优。以采集的风速、风力发电机转矩、桨距角作为输入信号,发电机转速数据作为输出信号,在Matlab环境中进行建模。实验结果表明,与传统算法相比,采用该方法的模型在准确性和收敛速度方面得到较大改善。