Performance of wind power industry development in China: A DiamondModel study

A reliable supply of energy is essential to maintain and to improve human being's living conditions. Compared to the conventional coal-fired approach, renewable energy (RE) helps to mitigate the impacts of greenhouse gas emissions to a large extent. As a newly developed sector with large resource potential and good commercial prospects, China's wind power industry is exceeding expectations. By 2008, installed capacity of wind power in China totaled over 12 GW, making China the fourth largest wind market in the world. However, China has to admit the gap with foreign leading countries, mainly in technical R&D for large-scale wind turbine generation units. This paper attempts to formulate an analytical model for studying and assessing factors that have significant impacts on the local industry. An improved dynamic Diamond Model is developed to help the international community to understand the status quo of the Chinese wind power industry. In order to build a stronger wind power industry, the elements identified in the model need to be strengthened.     

Review of recent offshore wind power developments in china

Rapid wind power development in China has attracted worldwide attention. The huge market potential and fast development of wind turbine manufacturing capacity are making China a world leader in wind power development. In 2010, with the newly installed wind power capacity and the cumulative installed capacity, China was ranked first in the world. In 2009, China also constructed and commissioned its first large offshore wind farm near Shanghai. Following earlier papers reviewing the state of China's onshore wind industry, this paper presents a broader perspective and up‐to‐date survey of China's offshore wind power development, making comparisons between the developments in the rest of the world and China, to draw out similarities and differences and lessons for the China offshore wind industry. The paper highlights six important aspects for China's offshore wind development: economics, location, Grid connection, technological development, environmental adaptation and national policies. The authors make recommendations for mitigating some outstanding issues in these six aspects for the future development of China's offshore wind resource. Copyright © 2012 John Wiley & Sons, Ltd.     

Electromagnetic energy harvester for monitoring wind turbine blades

The long composite blades on large wind turbines experience tremendous stresses while in operation. There is an interest in implementing structural health monitoring (SHM) systems inside wind turbine blades to alert maintenance teams of damage before serious component failure occurs. This paper proposes using an energy harvesting device inside the blade of a horizontal axis wind turbine to power a SHM system. The harvester is a linear induction energy harvester placed radially along the length of the blade. The rotation of the blade causes a magnet to slide along a tube as the blade axis changes relative to the direction of gravity. The magnet induces a voltage in a coil around the tube, and this voltage powers the SHM system. This paper begins by discussing motivation for this project. Next, a harvester model is developed, which encompasses the mechanics of the magnet, the interaction between the magnet and the coil, and the current in the electrical circuit. A free fall test verifies the electromechanical coupling model, and a rotating test examines the power output of a prototype harvester. Copyright © 2013 John Wiley & Sons, Ltd.     

Wind energy in China: Current scenario and future perspectives

Wind power in China registered a record level of expansion recently, and has doubled its total capacity every year since 2004. Many experts believe that China will be central to the future of the global wind energy market. Consequently, the growth pattern of wind power in China may be crucial to the further development of the global wind market. This paper firstly presented an overview of wind energy potential in China and reviewed the national wind power development course in detail. Based on the installed wind capacity in China over the past 18 years and the technical potential of wind energy resources, the growth pattern was modeled in this study for the purpose of prospect analysis, in order to obtain projections concerning the development potential. The future perspectives of wind energy development in China are predicted and analyzed. This study provides a comprehensive overview of the current status of wind power in China and some insights into the prospects of China's wind power market, which is emerging as a new superpower in the global wind industry.     

The present status and challenges of wind energy education and training in China

Wind energy has been identified in China as an important alternative energy source to balance its energy mix. By the end of 2012, wind power (2%) has surpassed nuclear power to become China's 3rd largest energy resource of electricity, only behind thermal power and hydropower. The rapid growth of China wind power industry in recent years has made China become the biggest market in the world. Meanwhile, it has created a big market for educational institutions to provide wind energy related education and training. The main objective of this study is to review current wind energy education and training in Chinese universities and training centers. Most of wind energy courses are provided by public universities because they have been accredited by Ministry of Education of China to offer students different options, including full-time and part-time degrees in Bachelor, Master or Ph.D. On-the-job training also has tremendous demand from the professionals who prefer short-term courses or on-site courses. Generally, the development of wind energy education and training lags behind the growth of wind power industry. Our study highlights the major opportunities and future challenges in China wind energy education and training.     

世界促进风电产业发展最新动向

近年来可再生能源发电发展迅速,其中风力发电表现尤为突出.在一些风电先行国家的推动下,风电机组大型化取得长足进展,单机容量从亚兆瓦级迅速提升到兆瓦级,研制中的10MW级风电机组即将问世.机组的大型化提高了风电的经济性和竞争力.风机设备利用率将由目前的25％左右提高至2015年的28％,同时投资成本将大幅下降,按照GWEC的高增长方案预测,投资成本将由2009年的1350欧元/kW降至2030年的1093欧元/kW.鉴于风力发电的间歇性和随机性,蓄电技术成为大量引入可再生能源的有效手段,美欧日等都投入专项经费支持蓄电技术的研究开发.IEA最近在报告中指出,与热电联产组合的方式可大幅扩大可再生能源的利用,其重点在于热供应.智能电网将成为解决风电大规模接入和输送问题的根本途径,它将使电力系统整体利用效率大大提高,有利于抑制发电厂的化石燃料消费.我国在智能电网方面已取得了一定成果,但仍面临许多问题.各国政府的可再生能源电力收购政策促进了风电产业的发展,其中德国的风电收购政策值得我国借鉴.     

Vibration response of a 2.3 MW wind turbine to yaw motion and shut down events

Structural health monitoring (SHM) is a process of implementing a damage detection strategy for a mechanical system. Wind turbine machinery stands to benefit from SHM significantly as the ability to detect early stages of damage before significant malfunction or structural failure occurs would reduce costs of wind power projects by reducing maintenance costs. Vibration analysis of dynamic structural response is an approach to SHM that has been successfully applied to mechanical and civil systems and shows some promise for wind turbine application. Traditionally, a setback to turbine vibration‐based SHM techniques has been the unavailability of turbine vibration response data. This study begins to address this issue by presenting vibration response for a commercial 2.3 MW turbine to a limited number of operating conditions. A database of acquired vibration response signals detailing turbine response to yaw motion, start‐up, operation and shutdown has been assembled. A Daubechies sixth‐order wavelet was used to perform an eight‐level discrete wavelet decomposition such that general trends and patterns within the signals could be identified. With further development, the presented analysis of vibration response may be integrated into routines to reduce downtime and failure frequency of utility scale wind turbines. Copyright © 2011 John Wiley & Sons, Ltd.     

Sensitivity of southern California wind energy to turbine characteristics

Using output from a high‐resolution meteorological simulation, we evaluate the sensitivity of southern California wind energy generation to variations in key characteristics of current wind turbines. These characteristics include hub height, rotor diameter and rated power, and depend on turbine make and model. They shape the turbine's power curve and thus have large implications for the energy generation capacity of wind farms. For each characteristic, we find complex and substantial geographical variations in the sensitivity of energy generation. However, the sensitivity associated with each characteristic can be predicted by a single corresponding climate statistic, greatly simplifying understanding of the relationship between climate and turbine optimization for energy production. In the case of the sensitivity to rotor diameter, the change in energy output per unit change in rotor diameter at any location is directly proportional to the weighted average wind speed between the cut‐in speed and the rated speed. The sensitivity to rated power variations is likewise captured by the percent of the wind speed distribution between the turbines rated and cut‐out speeds. Finally, the sensitivity to hub height is proportional to lower atmospheric wind shear. Using a wind turbine component cost model, we also evaluate energy output increase per dollar investment in each turbine characteristic. We find that rotor diameter increases typically provide a much larger wind energy boost per dollar invested, although there are some zones where investment in the other two characteristics is competitive. Our study underscores the need for joint analysis of regional climate, turbine engineering and economic modeling to optimize wind energy production. Copyright © 2012 John Wiley & Sons, Ltd.     

Wind electric power in the world and perspectives of its development in India

The global market for wind power is expanding faster than any other source of renewable energy. From just 4,800 MW in 1995 raise to fifteen-fold to reach 73,904 MW at the end of 2006. Top five wind electric power generating countries at the end of 2006 were Germany, Spain, United States of America (USA), India and Denmark. Since 1980s, when the first commercial wind turbine was deployed, their capacity, efficiency and visual design have all improved a lot. A modern wind turbine annually produces 180 times more electricity at less than half the cost per unit (kWh) than its equivalent twenty years ago. The largest turbines being manufactured now are of rated power of 5 MW capacity and a rotor diameter of 126 m. Modern turbines are modular and quick to install, whilst wind farms vary in size from a few MW to several hundred MW. Keeping these factors in view, an attempt has been made in this paper to present current advances in wind turbine generator technology. Wind energy scenario in the world in general and in India in particular have been presented. Further the cost components of wind turbine electric generation system have been included.     

基于Matlab/Simulink的风力机性能仿真研究

随着风力发电技术的发展,变速风力发电技术成为了风力发电发展的趋势。风力机作为变速风力发电机组的重要部分,其性能影响到风力发电机组的整体性能。根据变速风力机的静态性能特点,采用Matlab／Simulink软件对其进行建模,并给变速风力发电机组风力机输入模拟变速风速进行仿真研究,给出了风力机的静态性能数据和仿真波形。结果表明：通过调节影响风力机性能的各因素,保持发电机的转速与主导风速之间特定的最优比例系数,使得风力机保持在最佳叶尖速比下运行,跟随变速风速可实现最大风能捕获;对变速风力机的静态性能研究建模方法是正确可行的。     

风电与燃气轮机互补发电系统发电成本分析

在采用风电场与小型燃气轮机组成的互补系统发电特性参数的基础上,详细分析了互补系统发电成本的构成和各自的计算方法。采用新疆达坂城风电场的风速数据,基于互补系统的发电特性参数和风电场与燃气轮机电站的发电成本构成,应用改进过的等额支付折算法,在当前的技术条件和价格下,计算了风电场子系统和燃气轮机电站子系统各自的折旧成本、燃料成本和运行维护成本,得到了整滚发电系统发电成本的计算方法,为在新疆地区实现这种互补发电系统提供经济分析基础。     

Comparative assessment of performance of foreign and local wind turbine manufacturers in China

Compared to the conventional fossil fuel energy, wind power provides clean energy which can mitigate the impacts of greenhouse gas emission and optimize the electric power source structure. During the last decade, the strong support of the Chinese government has contributed to the rapid development of the Chinese wind power sector which has in turn resulted in a significant growth of the Chinese wind turbine manufacturing industry. This growth went through several phases including the initial approval of several leading global Wind Turbine Manufacturers (WTMs) to enter the Chinese market through various methods which included the establishment of wholly foreign-owned enterprises from 2005. Similarly, several government policies have contributed to the significant expansion in terms of both productivity and quantities by local Chinese WTMs. The entrance of foreign WTMs into the Chinese market coupled with the rapid growth of local WTMs has contributed to intense competition in China’s wind turbine manufacture market. This paper analyzes the characteristics of the wind turbine manufacturing industry in China and establishes a hierarchical structure of the WTMs’ competitive priority system. This system consists of 5 indicators and 10 sub-indicators. By comparing the different performances of each indicator, the competitive advantages and disadvantages of the foreign and local WTMs in the Chinese market are identified. The findings provide a valuable reference for the WTMs to improve their competitive priorities and to formulate their competitive strategy in the Chinese wind turbine market. This paper provides inputs for the sustainable development of wind power industry in other countries.     

Wind turbine generator systems. The supply chain in China: Status and problems

Wind turbine generator systems (WTGS) manufacture is booming in China. The key to success of the wind turbine generator industry is to construct the supply chain. However few papers focus on the supply chain. In China, many enterprises have started to manufacture the wind turbine generator system and the components. The supply chain of the wind turbine generator system is not well established in China. Many key components of WTGS still need to be imported, such as the principal axis bearing and electrical control systems. We review the status of wind turbine generator system manufacturing and analyze the problems of the supply chain in China. We analyze the problems about the supply chain from a macroscopic view. The aims of this paper are to let more scholars and experts know the status of the WTGS supply chain and to do something for building a successful industry in China.     

浅析水平轴风力机叶片设计叶尖速比的选择

设计叶尖速比是风力机叶片设计中需要考虑的重要因素,文中分析了叶尖速比对叶片的弦长、载荷、气动性能、整机的功率和发电量等的影响,讨论了设计叶尖速比的选择。并分析得出增大设计叶尖速比,能够减小叶片弦长、载荷、成本,提高气动性能,但会使机组发电量有所下降的结论。     

Wind energy technology and current status: a review

The paper provides an overview of the historical development of wind energy technology and discusses the current status of grid-connected as well as stand-alone wind power generation worldwide. During the last decade of the 20th century, grid-connected wind capacity worldwide has doubled approximately every three years. Due to the fast market development, wind turbine technology has experienced an important evolution over time. An overview of the different design approaches is given and issues like power grid integration, economics, environmental impact and special system applications, such as offshore wind energy, are discussed. Due to the complexity of the wind energy technology, however, this paper mainly aims at presenting a brief overview of the relevant wind turbine and wind project issues. Therefore, detailed information on further readings and related organisations is included.     

The extended Betz–Lanchester limit

A proposal for an extended formulation of the power coefficient of a wind turbine is presented. This new formulation is a generalization of the Betz–Lanchester expression for the power coefficient as function of the axial deceleration of the wind speed provoked by the wind turbine in operation. The extended power coefficient takes into account the benefits of the power produced and the cost associated to the production of this energy.By the simple model proposed is evidenced that the purely energetic optimum operation condition giving rise to the Betz–Lanchester limit (maximum energy produced) does not coincide with the global optimum operational condition (maximum benefit generated) if cost of energy and degradation of the wind turbine during operation is considered.The new extended power coefficient is a general parameter useful to define global optimum operation conditions for wind turbines, considering not only the energy production but also the maintenance cost and the economic cost associated to the life reduction of the machine.     

Wind turbine concept market penetration over 10 years (1995–2004)

The aim of this article is to investigate the market penetration and share of different wind turbine concepts during the years 1995–2004, a period that represents the maturational era of the modern wind power industry. A detailed overview is given based on suppliers' market data and concept evaluation for each individual wind turbine type sold by the Top Ten suppliers over the selected decade. The investigation is processing information on approximately 160 wind turbine types from 22 different manufacturers that have featured in the Top Ten list of wind turbine suppliers during 1995–2004. The analysis is based on comprehensive data covering approximately 97% of the cumulative wind power installed worldwide at the end of 2004. The article also provides an overall perspective on contemporary wind turbine concepts, classified with respect to both their speed control ability and power control type. Current and future trends for wind turbine concepts are discussed. Copyright © 2006 John Wiley &Sons, Ltd.     

Maximum power point tracker of wind energy conversion system

In this paper, a simple control strategy for an optimal extraction of output power from grid connected variable speed wind energy conversion system (WECS) is presented. The system consists of a variable speed wind turbine coupled to a permanent magnet synchronous generator (PMSG) through a gear box, a diode bridge rectifier, a dc-to-dc boost converter and a current controlled voltage source inverter. The maximum power point tracker (MPPT) extracts maximum power from the wind turbine from cut-in to rated wind velocity by sensing only dc link power. The MPPT step and search algorithm in addition to the DC–DC and DC–AC converters PWM controllers are simulated using MATLAB-SIMULINK software. The obtained simulation results show that the objectives of extracting maximum power from the wind and delivering it correctly to the grid are reached.     

Wind energy development and its environmental impact: A review

Wind energy, commonly recognized to be a clean and environmentally friendly renewable energy resource that can reduce our dependency on fossil fuels, has developed rapidly in recent years. Its mature technology and comparatively low cost make it promising as an important primary energy source in the future. However, there are potential environmental impacts due to the installation and operation of the wind turbines that cannot be ignored. This paper aims to provide an overview of world wind energy scenarios, the current status of wind turbine development, development trends of offshore wind farms, and the environmental and climatic impact of wind farms. The wake effect of wind turbines and modeling studies regarding this effect are also reviewed.     

Dynamic behaviour of wind power systems equipped with automatically regulated continuously variable transmission

High efficiency levels may be attained by wind turbines operating at varying speeds when the machine is made to run at a constant tip speed ratio. Previous papers have suggested incorporating a continuously variable transmission (c.v.t.) to achieve this purpose. Following the general recommendation of using efficient, reliable and economical technologies in wind power systems, one of these papers investigated whether a V-belt c.v.t. with automatically adjustable speed was compatible with a wind power system. The investigations in this case were carried out under steady-state conditions.In this paper, the behaviour of a wind power system equipped with a c.v.t. will be examined in turbulent wind conditions using a dynamic model. The simulation results will show that, when the actual wind speed fluctuations are taken into account, incorporating a c.v.t. between the turbine and the electric generator yields greater advantages in terms of energy output than it does when the system is assessed in the steady-state. The better quality of the electrical energy supplied will be examined and compared to that produced by a constant speed system. Finally, the behaviour of a wind power system equipped with a c.v.t. will be assessed as the temporal characteristics of the wind gusts change.