海上风力发电进展

近年来风力发电工业发展迅速，海上风能以其突出的优势受到重视。本文对近年来国外几种典型的海上风能资源评估方法做出述评，简要叙述了国外海上风电技术发展与应用的现状，分析了海上风能利用的经济性，并介绍了一些主要国家进一步发展海上风电的计划。     

我国海上“风电三峡”及非并网风电应用系统开发建议

位于长三角地区的浅海辐射沙洲风能资源十分丰富,而且具有地质条件优越,灾害性气象概率低,没有主航道和大型地下线缆,地处电力负荷中心,高新技术产业基础好,人才基础和资本市场发育良好,已具备理论、技术和实践基础等优势,非常适合发展大规模海上风电场。如开发其中15%的风能资源,即可兴建一个相当于年产4250×104t标煤、每年减排二氧化碳1.12×108t的永续绿色能源基地,而且不占用一亩耕地,不产生一个移民,也不存在生态安全问题。由于风能的自身特性,导致风电的波动性、间歇性和不规则性,使电网难以承受海上大规模风电场的巨大电能。建议采用非并网风电技术,在辐射沙洲地区建设若干"低碳型"高耗能绿色工业园区,利用风能替代化石能源,实现"高碳能源向无碳能源"的跨越。如海水淡化产业基地,变输电上岸为输水上岸;氯碱生产基地及PVC等衍生产业;以电解铝为重点的有色冶金产业基地;新型绿色煤化工产业基地等。     

新型海上风力发电及其关键技术研究

回顾国外海上风力发电场的发展,针对随着海水深度增加导致海上风力机成本急剧上升的矛盾,引入海上漂浮式风力机概念,并详细介绍其结构和特点,通过系统介绍海上漂浮式风力机组成部分和设计制造中的关键技术,最后得出海上漂浮式风机是一种潜力巨大的新型风力发电技术,值得进一步深入研究。同时,针对我国陆、海资源的具体情况,较为系统地提出了海上漂浮式风力机研究的需要关注的关键问题,指出了该研究所具有的巨大社会经济价值。     

Focus on the development of offshore wind power in China: Has the golden period come?

In recent years, Chinese Government paid more attention to the exploitation of offshore wind power, and it became an important trend in the development of wind power industry. However, the development of offshore wind power in China was still in the initial stage. Compared with land-based wind power, the development of off-shore wind power had not only weaknesses and uncertainties, but also strengths and opportunities. In order to research the development of offshore wind power, this paper summarized the aspects on policy, market, technology and development planning of offshore wind power in China, and then adopted SWOT method to analyze the influencing factors, which impact on the development of China's offshore wind power. At last, this article analyzed the internal and external factors that affect the golden period of offshore wind power development, and drew a conclusion that the golden period of offshore wind power in China will come in the future, and most likely around 2020.     

Coordinated control of series‐connected offshore wind park based on matrix converters

Optimization and reliability are two important aspects in design and operation of wind parks either for offshore as for onland emplacements. However, offshore locations demand conscientious effort in optimizing the size and the weight of each component in the energy conversion system because of the high investment and maintenance costs related with the supporting structures and transportation respectively. Achieving these two objectives requires the combination of different optimization stages, which consider a suitable design of the entire conversion system with innovative and more e?cient power electronic devices, optimized topology of the offshore grid and customized control strategies for optimizing the operation of the park. This paper presents an energy conversion concept for wind turbines on the basis of a reduced matrix converter (RMC) that will enable series direct current architecture in offshore wind parks thus preventing the need for offshore platforms. The RMC is built with bidirectional semiconductors that give reduced losses because of both superior topology and more e?cient semiconductors. The proposed conversion topology is tested in stationary state and transient operation. In addition to operational features of the concept, control and operation of a wind park with several turbines are presented. Dynamic operation of the turbine as well as the high‐voltage direct current transmission line effects are considered. Three types of models are therefore developed. First, an accurate and detailed model for analyzing one single turbine with the converter operated at high‐frequency switching is presented. This model considers a new modulation for the RMC. A second and simpli?ed model is used for small signal analysis. This model permits to simulate several series‐connected cluster during transient. Finally, an optimal direct current load ?ow model is used for evaluating stationary state operation. Results show the technical feasibility of the proposed concept and their advantages over conventional topologies. The paper also discusses the technological challenges that this type of offshore grid architecture will bring. Copyright © 2011 John Wiley & Sons, Ltd.     

理论发电量完成率在海上风电场评价中的应用

针对中国目前海上风电场起步较晚,技术不够完善,行业内对于海上风电场建设、机组选型和运营维护缺乏足够经验的特点,为完善海上风电场效能评价体系,提出理论发电量完成率的概念和相应的计算方法;同时,将理论发电量完成率这一指标代入实际案例进行计算分析。结果表明,理论发电量完成率能较好地反映风电机组和风电场的运行状态,能够将风资源状况和风电机组运行状态按照时间序列有机结合起来,是一个可操作性强且具有实际参考价值的指标,对海上风电场的评价和运行管理水平的提升有较好的指导意义。     

海上风电运维管理系统的研究与建议

分析了海上风电的运维特点及其运维管理系统的开发需求,梳理了国内外典型海上风电运维管理系统的特征及优缺点,最后提出对海上风电运维管理系统的开发建议.结果表明,运行管理、维护管理、设备管理和信息管理是运维管理系统不可或缺的功能模块,数据集成管理是系统构建的基础条件,智能化是运维管理系统的必然发展方向.     

中欧海上风电产业发展比较

相对于陆地风能,海上风能资源丰富,发电产能大,海上风电将是最有可能大规模发展的能源资源之一。欧洲是世界发展海上风力发电的先驱,从1991年至2009年,欧洲建设完成并投入运营的共有38个海上风电场,装机容量达到2056MW,其中一半以上的海上风电场是近5年建成的。欧洲海上风电产业拥有先进的核心技术,海上风电场正朝着大规模、深水化、离岸化方向发展,目前正处于示范阶段向商业扩展阶段的过渡时期。而我国虽然拥有丰富的海上风能资源,但海上风电产业的发展却比较缓慢,目前还处于研发阶段和示范阶段的过渡期,海上风电技术仍然面临着核心技术缺失、行业标准混乱、研发能力不足等问题。我国海上风电产业发展面临的主要问题包括:缺乏统筹;产能过剩、质量不高;难以盈利;缺少标准、无法推广等。为促进我国海上风电产业的发展,政府应进一步细化海上风能开发的有关规定,完善政策体系,统筹产业发展,采取多种措施推进政策具体落实;充分发挥市场作用,构建海上风电产品认证检测体系;提升核心技术含量,提高产品技术水平和工艺水平;加快培养专业人才。     

海上风力发电机组基础的选择

介绍了海上风力发电的发展现状,结合海上采油平台形式,对海上风电机组采用的基础定义、基础类型及其选择进行了介绍。     

无刷双馈风力发电机组的自抗扰功率解耦控制

对无刷双馈风力发电机组稳态运行时的功率分配关系进行了详细分析,在此基础上确定了最大风能捕获的控制策略.将自抗扰控制应用到无刷双馈电机有功功率与无功功率的解耦控制,将功率控制系统分解为有功功率子系统和无功功率子系统,从而建立了风力发电机组完整的功率控制模型.基于Matlab/Simulink的仿真结果表明无刷双馈风力发电机组自抗扰控制成功实现了有功功率与无功功率的解耦控制,不仅能够实现最大风能捕获,而且可以根据电网的实际需求调节机组无功功率的输出,验证了控制算法的有效性.     

Implications of seasonal and diurnal variations of wind velocity for power output estimation of a turbine: a case study of Grenada

This case study highlights the importance of taking into consideration diurnal variations of wind velocity for wind energy resources assessment. Previous studies of wind energy distribution that are based on the two-parameter Weibull density function have so far neglected to consider time of day fluctuations in wind speed, instead concentrating primarily on seasonal deviations. However, this has serious implications where such a wind energy model is the underpinning of calculations for the potential power production from a wind turbine and in particular where the timing of the energy output is essential to meet electricity loads. In the case of Grenada the energy output from a wind turbine during the day is approximately two times the output at night thereby fluctuating enormously around the seasonal mean distribution. When this is not taken into account the economic and technological viability of a wind turbine project may be overestimated or not even be identified. This work shows how a wind energy resources assessment based on the Weibull distribution model can be done and how the power output of a horizontal axis turbine is calculated. An analysis of the recorded wind data confirms the application of the Weibull density function as a suitable tool for modelling wind regimes. Copyright © 2003 John Wiley & Sons, Ltd.     

Offshore wind energy in the world context

The interest for the exploitation of the offshore wind energy is growing in Europe, where man land use is very high resulting in strong limitation to the installation of onshore wind farms. The today offshore operating wind power is 12 MW, with two wind farms in Denmark and one in Netherlands; it starts to be significant (0.6%) in terms of the onshore power, 2000 MW in Europe.In the world the onshore installed wind power is exceeding 4000 MW, but not so much up to now has been done on the offshore area outside Europe.The European four years experience on the prototypical offshore wind farms looks significantly promising and suggests to promote a similar approach in many densely populated coastal countries in the world with high electricity demand.Results of studies are presented on the offshore wind potential in the European countries and of the tentative evaluation for the Mediterranean basin, and the seas of USA and China. A review is made of the offshore applications, particularly for the Nothern European seas.Economy and environmental trends are illustrated in parallel to those of maturing offshore technology. It is suggested to prepare an action plan to promote the development of the offshore applications in the world context.     

Offshore wind turbine reliability and operational simulation under uncertainties

The fast‐growing offshore wind energy sector brings opportunities to provide a sustainable energy resource but also challenges in offshore wind turbine (OWT) operation and maintenance management. Existing operational simulation models assume deterministic input reliability and failure cost data, whereas OWT reliability and failure costs vary depending on several factors, and it is often not possible to specify them with certainty. This paper focuses on modelling reliability and failure cost uncertainties and their impacts on OWT operational and economic performance. First, we present a probabilistic method for modelling reliability data uncertainty with a quantitative parameter estimation from available reliability data resources. Then, failure cost uncertainty is modelled using fuzzy logic that relates a component's failure cost to its capital cost and downtime. A time‐sequential Monte Carlo simulation is presented to simulate operational sequences of OWT components. This operation profile is later fed into a fuzzy cost assessment and coupled with a wind power curve model to evaluate OWT availability, energy production, operational expenditures and levelised cost of energy. A case study with different sets of reliability data is presented, and the results show that impacts of uncertainty on OWT performance are magnified in databases with low components' reliability. In addition, both reliability and cost uncertainties can contribute to more than 10% of the cost of energy variation. This research can provide practitioners with methods to handle data uncertainties in reliability and operational simulation of OWTs and help them to quantify the variability and dependence of wind power performance on data uncertainties.     

A new synchronous generator based wind energy conversion system feeding an isolated load through variable frequency transformer

This paper aims to explore the possibility of synchronous generator (SG) based wind energy generation system feeding an isolated load using a latest power transmission technology i.e. variable frequency transformer (VFT). The proposed configuration does not employ any power electronics based interface as in conventional SG based stand-alone wind energy conversion systems (SWECS). For analysis, the simulation models of proposed configuration as well as conventional configuration have been developed under MATLAB-Simulink environment. A series of studies on power fed from the SG to the different loads at various SG input speeds has been carried out with the developed models. Further to analyze the effectiveness of the proposed method; the efficiency, total harmonic distortion (THD) of output voltage and THD of output current of the proposed method have been compared with those of the conventional method. From obtained results, it is observed that the proposed method is simple and does not produce harmonics. Moreover to validate the proposed scheme, an experimental analysis has been carried out. Further, the cost analysis of both systems has also been carried out. From the cost analysis, it is observed that the proposed system is cheaper than the conventional system.     

聚风导流型立轴风力机设计及气动性能分析

针对传统的立轴风力机风能利用率低的问题,应用正交优化法和流场数值模拟技术对聚风导流型立轴风力机的结构设计参数进行了优化设计。在同尺度下与传统立轴风力机进行了对比分析。结果表明,聚风导流型立轴风力机叶轮的输出功率、风能利用率及自启动特性均得到了显著提高。     

Controllable and affordable utility-scale electricity from intermittent wind resources and compressed air energy storage (CAES)

World wind energy resources are substantial, and in many areas, such as the US and northern Europe, could in theory supply all of the electricity demand. However, the remote or challenging location (i.e. offshore) and especially the intermittent character of the wind resources present formidable barriers to utilization on the scale required by a modern industrial economy. All of these technical challenges can be overcome. Long distance transmission is well understood, while offshore wind technology is being developed rapidly. Intermittent wind power can be transformed to a controllable power source with hybrid wind/compressed air energy storage (CAES) systems. The cost of electricity from such hybrid systems (including transmission) is affordable, and comparable to what users in some modern industrial economies already pay for electricity. This approach to intermittent energy integration has many advantages compared to the current strategy of forcing utilities to cope with supply uncertainty and transmission costs. Above all, it places intermittent wind on an equal technical footing with every other generation technology, including nuclear power, its most important long-term competitor.     

海上风电柔性直流输电变流器研究

简要分析海上风电柔性直流输电技术应用及变流器关键技术特点,设计基于柔性高压直流（HVDC）输电的风力发电机集中控制并网变流器主电路拓扑结构,基于电流峰值控制的三电平直流升压变换器双梯形波补偿方法,并利用滞环宽度可调的滞环比较器进行电流跟踪控制。仿真研究表明,该方法具有变流器功率管开关频率固定、减少开关应力及开关损耗、提高传输效率的特点,有助于减少开关器件电压应力和电抗器电流脉动值,提高系统运行的稳定性和可靠性。     

Scenarios for offshore wind power production for Central California Call Areas

In response to the growing interest in offshore wind energy development in California, the U.S. Bureau of Ocean Energy Management delineated three Call Areas for potential leasing. This study provides a comprehensive characterization and comparison of offshore wind power potential within the two Central California Call Areas (Diablo Canyon and Morro Bay) using 12- and 15-MW turbines under different inter-turbine spacing and wind farm size scenarios. Our analysis shows similar daily and seasonal patterns of wind power produced within the Call Areas, which peak in spring and during evening hours. Per-turbine power production is higher in the Morro Bay Call Area due to slightly higher hub-height wind speeds, whereas total power production is higher in the Diablo Canyon Call Area due to its larger size. Turbine type had a negligible impact on average power production per-unit-area because while larger turbines produce more power, they require greater inter-turbine spacing. Combined power production from the two fully built out Call Areas could equal nearly a quarter of California's current annual electrical energy production. A commercial-scale wind farm with a realized power output of 960 MW would require a footprint of at least half of the Morro Bay Call Area or at least a quarter of the Diablo Canyon Call Area. These results provide guidance on offshore wind development over the Central California Coast, and the framework demonstrated here could be applied to other wind data sets in other regions.     

无刷双馈风力发电机滑模功率解耦控制

首次采用现代控制理论中的滑模变结构方法研究了无刷双馈发电机(BDFM)运行时有功功率与无功功率的解耦控制,在状态方程的基础上,应用Lyapunov函数求得了有功功率与无功功率的滑模控制律,并在Matlab/Simu-link基础上建立了系统的仿真模型。仿真结果表明,滑模变结构控制能够有效的实现有功功率与无功功率的解耦控制,并实现了风能的最大功率捕获,证明了该控制策略的有效性。     

风力机大型化发展中的总体设计技术

简单介绍当前风能利用的发展,分析风电技术发展的趋势和主要特点;主要讨论风机大型化、柔性化等趋势引起的大型风机总体设计所面临的主要问题,总体设计技术是涉及气动、气动弹性、结构设计等多个学科、多方面的综合性问题,直接决定着大型柔性风机的性能、可靠性和寿命。本文主要分析了攻克总体设计难题所必需优先解决的风力机气动弹性载荷计算、气动弹性稳定性等问题。同时简要阐述了发展海上风机需要优先解决的相关技术问题,指出海上大型风力机分析首先需要着重考虑风—波联合作用下的机组气弹分析问题和考虑到近海风力机桩基特性的波浪载荷问题。