Influences on hydrogen production at a wind farm

If an affordable infrastructure for low-carbon-intensity hydrogen can be developed, then hydrogen is expected to become a key factor in decarbonizing the atmosphere. This research focuses on factors an existing wind farm operator would consider when weighing participating in the electricity market, the hydrogen market, or both.The solutions depend on the state of technology, which is changing rapidly, the local market structures, the local natural resources, and the local pre-existing infrastructure. Consequently, this investigation used an assessment approach that examined the variation of net present value. The investigation identified profitability conditions under three different scenarios: 1) Make and sell what makes economic sense at the time of production, 2) Use electrolyzer and fuel cell to consume power from the grid at times of low net demand and to produce electricity at times of high net demand, 3) Same as #2 but also market hydrogen directly when profitable.     

应用于风电场的STATCOM的仿真研究

利用Matlab中的动态仿真工具Simulink,建立了与无穷大系统相连的两机风电场模型。对系统发生三相短路故障时进行了仿真,在此基础上分析了静止同步补偿器(STATCOM)的补偿特性,并将其与SVC的补偿效果进行了比较。仿真结果表明,STATCOM能更好地提高风电场的暂态稳定性,保持风电场连续运行。     

UPFC对风电场稳定性影响的仿真研究

在风速变化过大或发生短路故障时,异步风力机的电压变化也大,馈入电网的有功也有较大变化,与系统交换的无功增加,超过了系统安全约束,导致风电场停运。UPFC可以控制电压和潮流,维持风电场电压,减少无功交换,提高风电场有功的输送极限,维持系统稳定。通过Matlab/Simulink建立仿真模型,对UPFC的作用进行了验证。     

Evaluation of wind farm efficiency and wind turbine wakes at the Nysted offshore wind farm

Here, we quantify relationships between wind farm efficiency and wind speed, direction, turbulence and atmospheric stability using power output from the large offshore wind farm at Nysted in Denmark. Wake losses are, as expected, most strongly related to wind speed variations through the turbine thrust coefficient; with direction, atmospheric stability and turbulence as important second order effects. While the wind farm efficiency is highly dependent on the distribution of wind speeds and wind direction, it is shown that the impact of turbine spacing on wake losses and turbine efficiency can be quantified, albeit with relatively large uncertainty due to stochastic effects in the data. There is evidence of the ‘deep array effect’ in that wake losses in the centre of the wind farm are under‐estimated by the wind farm model WAsP, although overall efficiency of the wind farm is well predicted due to compensating edge effects. Copyright © 2010 John Wiley & Sons, Ltd.     

2008年热带气旋对红海湾风电场发电量影响分析

通过对汕尾红海湾风电场2008年发电量以及影响风电场的热带气旋的统计分析,探讨了登陆热带气旋对风电场发电量的影响,以期为受热带气旋影响地区风机设计、风场选址及运营管理提供依据.     

Prioritizing of wind farm locations for hydrogen production: A case study

Many advantages of renewable energies, especially wind energy, such as abundance, permanence, and lack of pollution has encouraged many industrialized and developing countries to focus more on these clean and economic sources of energy. Identifying a good location that is suitable for the construction of a wind farm is one of the important initial steps in harnessing wind energy which is assessed this study. The purpose of this study is to prioritize and rank 13 cities of Fars province in Iran, in terms of their suitability for the construction of a wind farm. Six important criteria were used to prioritize and rank the cities. Wind power density is the most important criterion among these criteria which is calculated by obtaining the 3-h wind speed data between 2004 and 2013. DEA (Data Envelopment Analysis) method is used for prioritizing and ranking cities, and then AHP (Analytical Hierarchy Process), and FTOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) methods are used to assess the validity of results. It is concluded that Izadkhast city is the suggested location for the construction of wind farm. The utilizing a wind-hydrogen energy conversion system will result in a substantial amount of hydrogen production (averagely 21.9 ton/year) when a 900 kW wind turbine is installed in this location.     

风电场风电机组的接地设计

较系统地介绍了风电场风电机组对接地电阻的要求、接地设计思路及方法,并提供实际工程中接地网布置图实例作为参考。     

Adjustment of wind farm power output through flexible turbine operation using wind farm control

When the installed capacity of wind power becomes high, the power generated by wind farms can no longer simply be that dictated by the wind speed. With sufficiently high penetration, it will be necessary for wind farms to provide assistance with supply‐demand matching. The work presented here introduces a wind farm controller that regulates the power generated by the wind farm to match the grid requirements by causing the power generated by each turbine to be adjusted. Further, benefits include fast response to reach the wind farm power demanded, flexibility, little fluctuation in the wind farm power output and provision of synthetic inertia. Copyright © 2015 John Wiley & Sons, Ltd.     

Using wind velocity estimated from a reanalysis to minimize the variability of aggregated wind farm production over Europe

In this work we use the mean‐variance portfolio optimization, using as input the power derived from the wind and density results of meteorological model simulations (ERA‐Interim reanalysis), to minimize the variability of the wind power produced in a large region. The methodology involves selecting the placement of the wind farms on a high spatial resolution grid. We used the EU‐28 region to check the method and perform sensitivity tests. We studied the influence of the ratio between the total installed power of the whole domain (P_t) and the maximum power that can be installed per cell (P_mi) on the variability of wind power yield. The results show that the reliability of the electrical system improves when P_mi grows and worsens when P_t grows. A quadratic fit relates the variability of the system and the aforementioned ratio. The optimization procedure tends to select groups of terrain cells where wind farms should be installed. These groups grow when more energy production is demanded of the system, but they roughly maintain their location. There is some evidence that in a larger region greater system reliability could be achieved. Most of the selected cells have either a high or a low capacity factor and those with the latter are crucial in enhancing system reliability.     

不同风电场模型对风电场电压的影响评估

目前,实际的电力系统仿真计算将风电场处理为一台风电机组。随着并入输电网的风电容量持续增加,仍按照一台风机等效对系统仿真计算造成的误差不容忽视,该误差能引起风电场内部保护装置的误动作。文章针对不同风电模型对风电场电压的影响做了详细比较,并给出了量化指标。经过试验仿真分析得出以下结论:不同风电场模型对风电场出口和并网点电压的影响不同,当恒速异步风电机构成的风电场采用一台风电机等效时,将会使风电场出口的相电压计算平均误差达到16.667%。因此,为保证仿真精度与风电场保护的正确动作,在对含风电场的电力系统进行仿真计算时,应将风电场处理为若干台风电机。     

某风电场风力发电机组故障诊断

为了准确判断风电机组的运行状态及故障,提出了基于常规分析—振动幅值分析—波形频谱分析的故障诊断流程,阐述了针对风电机组的幅值分析方法和波形频谱分析方法,并通过对某机组异响的根源探究实例,准确地诊断出机组异响来源于齿轮箱太阳轮,可为风电机组故障诊断技术提供依据。     

A passively self-adjusting floating wind farm layout to increase the annual energy production

Wake losses inside a wind farm occur due to the aerodynamic interactions when a downwind turbine is in the wake of upwind turbines. The ability of floating offshore wind turbines (FOWTs) to relocate their positions in the horizontal plane introduces an opportunity to decrease the wake losses in a floating wind farm (FWF). Our goal is to use this ability to passively move the downwind FOWT out of the wake of upwind ones. Since the mooring system (MS) attached to a FOWT is responsible for its station keeping, the horizontal motions of the FOWT depend on the MS design. Hence, if we can design the MS to passively move the FOWT out of the wake, we can increase the FWF annual energy production (AEP). In this paper, we investigate if we can benefit from relocating FOWTs in a FWF and increase its AEP. In addition, we present a novel approach that considers the ability of a FOWT to relocate its position as a new degree of freedom (DoF) in the FWF layout design. This means we will have a self-adjusting wind farm layout where the FOWTs passively re-arrange themselves depending on the wind direction and the wind speed. Consequently, we will have a slightly different wind farm layout for every wind direction and every wind speed. To achieve this layout, we include the MS design as part of the FWF's layout design. In a self-adjusting FWF layout, each FOWT is attached to a customized MS design allowing it to relocate its position in the best way possible according to the wind direction, to increase the overall AEP of the wind farm. The results of one case study show that the novel approach can increase the FWF's AEP by 1.6% when compared with a current state of the art optimized floating wind farm layout. Finally, we implemented our method as an open-source python tool to be used and enhanced further within the wind energy community.     

Analysis of wind farm islanding experiment

This paper deals with the problems related to an islanding experiment performed at Rejsby Hede in Denmark. During the experiment several interesting observations were made in connection to distortion of voltages and currents. Observations were also made in connection to variation of frequency and phase. In this paper the data are analyzed in three different ways and the results are related to the physics of the electric system     

浅谈风电场工程设计

1前言风电场工程设计是指在风电场工程施工之前,设计单位根据已批准的设计任务书,为实现拟建风电场项目的技术、经济要求,拟定建筑、安装工程等所需的规划、图纸、数据等技术文件的工作。风电场设计是风电场项目由计划变为现实具有决定意义的     

Dependence of optimal wind turbine spacing on wind farm length

Recent large eddy simulations have led to improved parameterizations of the effective roughness height of wind farms. This effective roughness height can be used to predict the wind velocity at hub‐height as function of the geometric mean of the spanwise and streamwise turbine spacings and the turbine loading factors. Recently, Meyers and Meneveau used these parameterizations to make predictions for the optimal wind turbine spacing in infinitely large wind farms. They found that for a realistic cost ratio between the turbines and the used land surface, the optimal turbine spacing may be considerably larger than that used in conventional wind farms. Here, we extend this analysis by taking the length of the wind farm, i.e. the number of rows in the downstream direction into account and show that the optimal turbine spacing strongly depends on the wind farm length. For small to moderately sized wind farms, the model predictions are consistent with spacings found in operational wind farms. For much larger wind farms, the extended optimal spacing found for infinite wind farms is confirmed. Copyright © 2015 John Wiley & Sons, Ltd.     

Evaluation of short-term wind predictability

Short-term wind predictability is the ability to foresee hourly wind energy one or several days in advance. The problem is addressed in general and the focus is on the form in which the predictability information should be given, which power models should be selected, and how to formulate the problem in a convenient perspective and approach its solution. A theory is developed to provide the basis for a quantification of the value of predictability. The concept of operational planning capacity is introduced together with some definitions and derived results. Based on these results, an algorithm to quantify the value of predictability is proposed. Numerical results illustrate the various steps of the algorithm     

Design of wind farm layout for maximum wind energy capture

Wind is one of the most promising sources of alternative energy. The construction of wind farms is destined to grow in the U.S., possibly twenty-fold by the year 2030. To maximize the wind energy capture, this paper presents a model for wind turbine placement based on the wind distribution. The model considers wake loss, which can be calculated based on wind turbine locations, and wind direction. Since the turbine layout design is a constrained optimization problem, for ease of solving it, the constraints are transformed into a second objective function. Then a multi-objective evolutionary strategy algorithm is developed to solve the transformed bi-criteria optimization problem, which maximizes the expected energy output, as well as minimizes the constraint violations. The presented model is illustrated with examples as well as an industrial application.     

风电场微观选址及发电量预测的探讨

对风资源评估、选址地面情况和风机位置的排布等影响风电场微观选址的因素进行了分析.阐述了风电场发电量的预测方法,通过实例说明如何使用相关软件来预测风电场发电量,并根据预测结果对风电场微观选址注意事项进行了探讨.     

老爷庙风电场风能资源评价

本文利用老爷庙风电场2001年4月～2002年4月逐时平均风向、风速资料，对老爷庙风电场的风能资源各参数进行了计算和分析，并与附近星子气象站累年或同期资料进行比较，对老爷庙风电场风能资源进行评价。     

Models for monitoring wind farm power

Different models for monitoring wind farm power output are considered. Data mining and evolutionary computation are integrated for building the models for prediction and monitoring. Different models using wind speed as input to predict the total power output of a wind farm are compared and analyzed. The k-nearest neighbor model, combined with the principal component analysis approach, outperforms other models studied in this research. However, this model performs poorly when the conditions of the wind farm are abnormal. The latter implies that the original data contains many noisy points that need to be filtered. An evolutionary computation algorithm is used to build a nonlinear parametric model to monitor the wind farm performance. This model filters the outliers according to the residual approach and control charts. The k-nearest neighbor model produces good performance for the wind farm operating in normal conditions.