带有RCC的异步风力发电机系统的特性分析

介绍了带有转子电流控制器（RCC）的变桨距调节异步风力发电机系统的基本原理及其控制策略。基于Saber仿真软件，建立了变桨距风力机、绕线式异步发电饥、转子电流控制器以及风速等的仿真模型，并以此为基础深入研究了该类风力发电机系统的运行特性。仿真分析表明，引入转子电流控制可以明显改善发电机的输出电能品质，降低变桨距风力机的调节频率，延长变桨距机构的使用寿命。制作了一套7．5kW模拟异步风力发电机的RCC系统，对带有RCC的异步风力发电机系统进行了模拟实验研究。     

运用轨迹灵敏度的水电系统动态安全分析

提出了基于轨迹灵敏度的方法来研究水电系统参数及初始运行状态不确定性对水电系统动态安全的影响。研究建立水机电联合系统动态模型及其轨迹灵敏度模型,通过水电系统动态过程对其控制系统参数及初始运行状态的灵敏度来分析其参数及初始运行状态对整个水电系统动态过程的影响．提出对系统安全运行较大的参数及初始运行状态特点、参数的安全调整范围。     

风力发电系统权系数独立变桨距矢量控制

风电系统具有多变量、非线性以及不确定等特点,为了减小叶片不平衡载荷造成的机组疲劳和振动,在2 MW风力发电系统中采用了基于权系数的独立变桨距矢量控制。在MATLAB软件中建立机组的数学模型,与统一变桨距系统的控制效果进行比较,通过仿真验证了权系数独立变桨距矢量控制方案的合理性和优越性。     

双馈风电机全风况条件下小干扰稳定性分析

以双馈风力发电单机无穷大系统为研究对象,建立了风力机、双馈感应发电机、变频器控制系统及桨距角控制系统的数学模型和全阶微分代数方程式,用分析系统特征值和相关因子的方法研究闭环控制系统的小干扰稳定特性。研究得到全风况运行条件下系统的特征根轨迹及相应的振荡模式和阻尼特性,给出了各振荡模式和衰减模式与相应状态变量参与度的关系,为电力系统稳定器的设计提供了一定的理论参考。     

风力发电的运行系统及操控方法

众所周知,风能是一种比较清洁、实用并且对环境比较友好的可替代性能源。在未来的能源战略发展中,风力能源将具备越来越重要的作用。着眼于风力发电新型能源在生产过程中的运行系统和操作方法,针对风力发电的运行系统和可控制问题进行了探讨与研究。     

基于叶素理论的风力机组建模与仿真

基于叶素理论建立了风力发电机组空载状况下的数学物理模型,以攻角为控制对象设计控制器,在此基础上,以Matlab/Simulink为工具,建立了系统仿真模型,采用"试凑法"选择PI控制器的参数,通过设定风速分析了风力发电机组的运行特性,仿真结果验证了理论分析的正确性。该研究对控制器的设计具有参考价值。     

基于迭代自适应方法的风机变桨系统优化控制

基于PID控制原理的风机的变桨控制系统在极端风况下调节性能较差,提出一种针对风电机组变桨系统的自适应控制算法,以优化风机在极端风况下的发电性能.利用最优控制原理,风机变桨的控制系统开发基于迭代的自适应控制算法,使风机在满发的情况下适应不同的工况,减少风机的故障,保护停机频次,提升风机的发电性能.通过在Python环境中...     

基于FEM组合结构动态灵敏度分析

探讨了用有限元法对组合结构进行动力学灵敏度分析的一种新的思路。将组合结构试验模态测试和有限元结合起来识别结合面动力学参数，组合结构之间用虚拟联结件来联结，从而建立了组合结构完整的动力学分析有限元模型，并进行动态灵敏度分析和优化设计。基于此思路和方法利用I—DEAS软件分别对柴油机机体一缸盖组合模型和某大型龙门式组合机架结构进行了动态灵敏度分析，结果表明此方法对分析一般的组合结构动力学优化设计具有普遍意义。     

汽轮机调节系统的不灵敏度对系统性能影响的仿真分析

本文的研究发现,汽轮机液压调节系统各部件的不灵敏度对系统总体性能的影响各不相同,修正了传统观念.     

发动机缸体固有频率对加强筋厚度的灵敏度分析

探讨了适于复杂结构固有频率的灵敏度分析的方法。针对某1．3 L铝合金发动机,分析了发动机缸体的固有频率对筋厚度的灵敏度,得到了对结构的固有频率正影响比较大的加强筋,在其附近区域采取相应的结构和参数修改,提高了缸体的固有频率。分析结果表明,灵敏度分析为发动机缸体动力学修改提供了依据,是发动机NVH性能提升的有效途径。     

Impact of wind farms on a power system. An eigenvalue analysis approach

This paper analyzes the frequency dynamic behavior in a power system with a high wind power penetration. To this end, wind farms equipped with squirrel cage and doubly fed induction generators are compared. Aspects of the modeling of the different kinds of wind generation and power systems are cited. Then, it is shown, through an eigenvalue analysis, that wind farms equipped by doubly fed induction machines, adequately controlled, can contribute to improve the frequency dynamics. Simulations are presented which verify the theoretical results.     

Alternative wind power : A next generation wind power technology?

Present day wind turbines (large blade Props on Pole or POPs) have continued to evolve to ever larger sizes requiring massive blades, gearboxes or large, complex customized generators. This continuous increase in size has subsequently increased the costs and complexity of manufacturing, transporting, constructing and maintaining these systems. In this article, Alfred L. Weisbrich, ENECO Texas LLC, USA discusses an alternative wind power technology design, the Wind Amplified Rotor Platform (WARP^TM) which uses many identical smaller vertically integrated modules as opposed to one large generator. The modular design can be easily and relatively inexpensively volume produced and implemented both in traditional electric utility scale wind farms as well as in marine based offshore wind farms sites.     

转子侧采用直接功率控制的双馈风力发电系统

在研究双馈感应发电机(DFIG)数学模型的基础上,分析了对称电网条件下DFIG定子侧输出有功、无功功率的组成,对转子侧采用了一种新颖的直接功率控制(DPC)方法控制变换器的工作状态,实现对定子端输出的有功、无功功率的控制,较好地实现了二者的解耦。基于Matlab建立了DFIG风力发电系统仿真模型。仿真结果显示,所采用的方案具有快速的动态响应功能和良好的控制效果。     

Global sensitivity analysis of wind turbine power output

The dynamics of wind turbine behavior are complex and a critical area of study for the wind industry. Identification of factors that cause changes in turbine performance can sometimes prove to be challenging, whereas other times, it can be intuitive. The quantification of the effect that these factors have is valuable for making improvements to both power performance and turbine health. In commercial farms, large quantities of meteorological and performance data are commonly collected to monitor daily operations. These data can also be used to analyze the relationship between each parameter in order to better understand the interactions that occur and the information contained within these signals. In this global sensitivity analysis, a neural network is used to model select wind turbine supervisory control and data acquisition system parameters for an array of turbines from a commercial wind farm that exhibit signs of wake interaction. An extended Fourier amplitude sensitivity test is then performed for 2 years of 10‐min averaged data. The study examines the primary and combined sensitivities of power output to each selected parameter for two turbines in the array. The primary sensitivities correspond to single parameter interactions, whereas combined sensitivities account for interactions between multiple parameters simultaneously. Highly influential parameters such as wind speed and rotor rotation frequency produce expected results; the extended Fourier amplitude sensitivity test method proved effective at quantifying the sensitivity of a wide range of more subtle inputs. These include blade pitch, yaw position, main bearing and ambient temperatures as well as wind speed and yaw position standard deviation. The technique holds promise for application in full‐scale wake studies where it might be used to determine the benefits of emerging power optimization strategies such as active wake management. The field of structural health monitoring can also benefit from this method. Copyright © 2013 John Wiley & Sons, Ltd.     

Optimization of wind turbine micro-siting for reducing the sensitivity of power generation to wind direction

In the optimization of wind turbine micro-siting of wind farms, the major target is to maximize the total energy yield. But considering from the aspect of the power grid, the sensitivity of wind power generation to varying incoming wind direction is also an essential factor. However, most existing optimization approaches on wind turbine micro-siting are focused on increasing the total power yield only. In this paper, by employing computational fluid dynamics and the virtual particle model for the simulation of turbine wake flow, a sensitivity index is proposed to quantitatively evaluate the variation of power generation under varying wind direction. Typical turbine layouts obtained by existing power optimization approaches are evaluated for stability. Results indicate that regularly arranged turbine layouts are not suitable for stable power production. Based on solutions from the power optimization, a second-stage optimization using Particle Swarm Optimization algorithm is presented. The proposed optimization method adjusts the positions of the turbines locally, aiming at increasing the stability of wind farm power generation without damaging its advantage of high power yield. Case studies on flat terrain and complex terrain both demonstrate the effectiveness of the present local adjustment optimization method.     

PSCAD/EMTDC-based simulation of wind power generation system

This paper proposes a novel simulation method of wind power generation system (WPGS) using PSCAD/EMTDC. The pitch control-based rotation speed control scheme of turbine under variable wind speed is implemented. For the purpose of achieving effective and user-friendly simulation method for utility interactive (grid connected) WPGS, real weather condition-based WPGS simulation (RW–WPGS) is performed using PSCAD/EMTDC. It is not easy, in general, to consider the RW conditions in the WPGS simulation using the EMTP or PSPICE type of simulators. External parameters of the RW conditions, however, are necessary to improve the simulation accuracy.The components modeling of wind turbine system is also studied and the real weather conditions are introduced by the interface method of a non-linear external parameter of the PSCAD/EMTDC. The outcomes of the simulation demonstrate the effectiveness of the proposed simulation scheme.     

Application of energy capacitor system to wind power generation

In this paper, it is reported that energy capacitor system (ECS), which combines power electronic devices and electric double‐layer capacitor, can significantly decrease voltage and power fluctuations of grid‐connected fixed‐speed wind generator. The proper selection of wind farm output power reference is still a problem for smoothing the wind farm output power. This paper proposes exponential moving average to generate the reference output power of a grid‐connected wind farm. The objective of the control system is to follow the line power reference by absorbing or providing real power to or from the ECS. Moreover, the necessary reactive power can also be supplied to keep the wind farm terminal voltage at the desired reference level. Real wind speed data were used in the simulation analyses, which validate the effectiveness of the proposed control strategy. Simulation results clearly show that our proposed ECS can be suitable for wind power application. Copyright © 2007 John Wiley & Sons, Ltd.     

隧道式烟囱太阳热风发电系统

太阳热风发电系统的基本原理如图1所示，由3个主要部件构成：底部为太阳能空气加热器（集热棚），中间为太阳能烟囱，烟囱底部布置风力发电机组。太阳辐射加热玻璃屋顶下温室内的空气，致使热空气源源不断流向位于温室中央的太阳能烟囱；烟囱两端空气的温差和压差导致空气沿太阳能烟囱上升产生动能，在烟囱内安装风力透平发电机，产生电能，风最后从烟囱顶部排入大气。其能量流向为太阳光能先变成空气的热能，再转变为风的动能，再转变为风力透平的动能，最后得到电能。     

Dispatch modeling of a regional power generation system – Integrating wind power

A modeling tool has been developed which can be used to analyze interaction between intermittent wind power generation and thermal power plant generation in a regional electricity grid system. The model uses a mixed integer programming (MIP) approach to determine the power plant dispatch strategy which yields the lowest systems costs. In the model, each large thermal plant is described separately, including properties such as start-up time, start-up cost and minimum load level. The model is evaluated using western Denmark as a case study.For western Denmark, it is found that the inclusion of start-up performance (i.e. start-up time and related costs) and minimum load level of the power generating units have a significant impact on the results. It is shown that the inclusion of these aspects influences the analysis of the effect of wind power variations on the production patterns of thermal units in the system. The model demonstrates how the introduction of wind power production and associated variations change the dispatch order of the large thermal power plants in the western Denmark system so that the unit with the lowest running costs no longer has the highest capacity factor. It is shown that this effect only is detected if start-up performance and minimum load level limitations are included in the optimization. It can also be concluded that start-up performance and minimum load level must be taken into account if the total system costs and emissions are not to be underestimated. The simulations show that if these aspects are disregarded, both total costs and total emissions of the power system are underestimated, with 5% in the case of western Denmark. Models such as the one developed in this work can be efficient tools to understand the effects of large-scale wind power integration in a power generation system with base load plants.     

风力发电前景广阔

被称为“蓝天白煤”的风力资源,是一种取之不尽,又不会产生任何污染的可再生能源。人类早在远古时代便开始利用风力,但直到１９世纪末丹麦才建成全球第一个风力发电装置。由于风力发电与火电、核电、水电等其它发电方式相比有诸多优点,所以,本世纪８０年代以来,世界风电装机容量迅猛增长。１９８１年为１５兆瓦,１９９２年已达２６５２兆瓦,１３%的年增长率使风力发电成为世界上增长速度最快的发电方式之一,目前仍保持着快速发展的势头。１９９９年１０月５日,欧洲风能协会在布鲁塞尔发表了一项国际能源研究报告。报告称,风力发电到２０２０…