TSMC励磁的双馈风力发电系统研究

将双级矩阵变换器(TSMC)应用于变速恒频(VSCF)风力发电系统。该系统采用TSMC作为双馈发电机的交流励磁电源,利用定子磁场定向的矢量变换控制实现发电系统有功功率和无功功率的独立调节;并采用最大风能捕捉策略,实现不同风速下跟踪最大风能曲线,实现风能的有效利用。仿真结果表明该系统具有良好的稳、动态变速恒频运行特性,输出可以实现有功、无功功率的独立调节,且输出电能质量高。验证了所提控制方案的正确性和有效性。     

分布式风-光互补能源利用系统

提出充分利用风能和太阳能的互补性,设计了风能和太阳能联合供能系统在运行中能量产生、储备、利用等各个环节的工作方式,实现可靠、高效地运行,为用户提供了生活用电与供热。该系统很好地利用了风-光可再生资源在季节、天气、地域上的互补性,可拓展风能和太阳能经济利用的范围。该系统在风-光丰富的广大农村地区具有很好的应用和发展前景。     

国外可再生能源文献信息

GW030401采用模糊逻辑控制原理使风能系统产生最大电力的跟踪控制.MohamedAZ,EskanderMN,GhaliFA.RenewableEnergy,2001,23(2):235～245.介绍了一种具有异步(交-直-交)联络线的公用交互式风能转换系统。该控制系统旨在从风能系统中识别和获取最大发电量,并将其投入应用。在设计风能转换系统的跟踪控制器时采用了一种模糊逻辑控制技术。在设计阶段,应用了一种风速梯级模型,同时,利用真实的气象资料测试了这种模糊逻辑控制器的风能转换系统的性能,其稳定性和有效性通过控制系统的模拟结果得到了验证。GW030402应用光电和风电给小型孤立…     

基于MATLAB的风力发电机组建模和仿真研究

变桨距控制技术是风力发电机组提高对风能的利用的有效方法,由于外界环境的随机性和控制变量的多样性,风力发电系统是一个非线性的系统,其数学模型的建立和仿真是一个难点。本文基于Matlab软件平台,采用机理建模法建立了风力发电机组的各个分系统的子模型,组合成整个机组的数学模型,并采用PID控制算法实现风力发电机组在不同风速下对风能利用的最大化,仿真结果验证了系统模型和控制算法的正确性,为风机控制的创新奠定了理论基础。     

基于无源性理论的风力机最大风能捕获控制

讨论了具有随机性风速变化和非线性的风电系统的最大风能捕获控制问题,系统采用基于无源性控制方案下的浆距角和触发角双输入控制方案,通过选择适当的状态稳态特性和注入阻尼的方法,将风能的最大捕获与系统的全局稳定性相结合,设计出了一种对风速变化和参数摄动具有鲁棒性且使风电系统具有良好动态特性的控制系统。仿真结果显示,对于具有随机性风速变化和变参数风电系统,该控制策略可以实现风能的最大捕获。     

垂直轴永磁同步风力发电机侧整流器的终端滑模控制

滑模控制在提高滑模面速度时会有较大抖振。文章设计了一种新型滑模控制器,该滑模控制器不需要微分估计器及额外的滤波装置,就可抑制系统的抖振。结合矢量控制技术,采用文章方法分别设计永磁同步发电系统的速度外环和电流内环的滑模控制器,保证转速和电流在有限时间内跟踪相应的给定参考,实现最大风能捕获。仿真结果表明:与PI控制器和线性滑模控制器相比较,该控制策略实现风力发电机侧的最大风能捕获的同时,提高了系统的动静态性能。     

基于自抗扰控制器的风力发电系统的最大风能捕获控制

根据自抗扰控制器的原理,设计了风力发电系统的最大风能捕获控制器。将风能转矩的不确定性与系统的摩擦不确定性统一视为系统的未知干扰,通过扩张状态观测器来估计,然后利用非线性反馈控制律进行补偿,使系统的控制律仅与系统的给定输入和输出有关,减少控制过程中的检测量,将复杂的控制过程简化。通过非线性跟踪一微分器的适当设计,实现了最大风能捕获,证明控制策略的可行性,同时通过参数的改变,验证了该控制方法的具有很强的适应性和鲁棒性。     

风力机特性的直流电动机模拟及其变速恒频风力发电研究中的应用

为了能在不具备风场环境的实验室条件下对双馈异步发电机的交流励磁发电技术进行实验研究,该文提出了采用直流电动机模拟风力机工作特性的实现方案。该方法基于风力机和直流电动机在功率(转矩)特性上的相似性,采用转矩控制方案实现了风力机特性的直流电动机模拟,进而构建了整个变速恒频DFIG风力发电装置的实验系统。首次在实验室环境下实现了最大风能动态追踪、P、Q解耦控制的实验研究,验证了直流电动机模拟风力机特性的可实现性和变速恒频DFIG风力发电系统最大风能追踪控制策略的正确性。     

微型风力热泵系统的研究

研究了利用风能的一种新型装置，将风能通过风力叶轮转化为机械能后，通过变速器带动微型制冷用压缩机，压缩机则与其它装置组成布雷顿热泵循环，利用热泵循环产生的热量加热居民水箱中的水，供给居民使用。通过计算分析，该方案是可行的，同时减少了能量转换环节，实现了可再生能源的合理利用，并且从另一个角度解决了风力资源的不稳定性问题。     

全球太阳能风能分布图问世

联合国环境规划署近日公布了由全球各地25个研究机构共同绘制的全球太阳能和风能分布图。该项目名为“太阳能与风能资源可利用评估”始于2001年，由全球环境基金提供资金支持，利用卫星和地面工具采集到一系列数据来评估风能和太阳能资源。     

Framework design of a hybrid energy system by combining wind farm with small gas turbine power plants

Owing to the stochastic characteristic of natural wind speed, the output fluctuation of wind farm has a negative impact on power grid when a large-scale wind farm is connected to a power grid. It is very difficult to overcome this impact only by wind farm itself. A novel power system called wind-gas turbine hybrid energy system was discussed, and the framework design of this hybrid energy system was presented in detail in this paper. The hybrid energy system combines wind farm with several small gas turbine power plants to form an integrated power station to provide a relatively firm output power. The small gas turbine power plant has such special advantages as fast start-up, shutdown, and quick load regulation to fit the requirement of the hybrid energy system. Therefore, the hybrid energy system uses the output from the small gas turbine power plants to compensate for the output fluctuation from the wind farm for the firm output from the whole power system. To put this hybrid energy system into practice, the framework must be designed first. The capacity of the wind farm is chosen according to the capacity and units of small gas turbine power plants, load requirement from power grid, and local wind energy resource distribution. Finally, a framework design case of hybrid energy system was suggested according to typical wind energy resource in Xinjiang Autonomous Region in China.     

Framework design of a hybrid energy system by combining wind farm with small gas turbine power plants

Owing to the stochastic characteristic of natural wind speed, the output fluctuation of wind farm has a negative impact on power grid when a large-scale wind farm is connected to a power grid. It is very difficult to overcome this impact only by wind farm itself. A novel power system called wind-gas turbine hybrid energy system was discussed, and the framework design of this hybrid energy system was presented in detail in this paper. The hybrid energy system combines wind farm with several small gas turbine power plants to form an integrated power station to provide a relatively firm output power. The small gas turbine power plant has such special advantages as fast start-up, shutdown, and quick load regulation to fit the requirement of the hybrid energy system. Therefore, the hybrid energy system uses the output from the small gas turbine power plants to compensate for the output fluctuation from the wind farm for the firm output from the whole power system. To put this hybrid energy system into practice, the framework must be designed first. The capacity of the wind farm is chosen according to the capacity and units of small gas turbine power plants, load requirement from power grid, and local wind energy resource distribution. Finally, a framework design case of hybrid energy system was suggested according to typical wind energy resource in Xinjiang Autonomous Region in China.     

The effect of spatial dispersion of wind power plants on the curtailment of wind power in the Greek power supply system

To meet the national target of 29% for electricity production from renewable energy sources by 2020 in Greece, effective implementation of massive wind power installed capacity into the power supply system is required. In such a situation, the effective absorption of wind energy production is an important issue in a relatively small and weak power system such as that of Greece, which has limited existing interconnections with neighboring countries. The curtailment of wind power is sometimes necessary in autonomous systems with large wind energy penetration. The absorption or curtailment of wind power is strongly affected by the spatial dispersion of wind power installations. In the present paper, a methodology for estimating this effect is presented and applied for the power supply system of Greece. The method is based on probability theory, and makes use of wind forecasting models to represent the wind energy potential over any candidate area for future wind farm installations in the country. Moreover, technical constraints imposed by the power supply system management, the commitment of power plants and the load dispatch strategies are taken into account to maximize the wind energy penetration levels while ensuring reliable operation of the system. Representative wind power development scenarios are studied and evaluated. Results show that the spatial dispersion of wind power plants contributes beneficially to the wind energy penetration levels that can be accepted by the power system. Copyright © 2009 John Wiley & Sons, Ltd.     

Review on combined wind power generation and energy storage systems

储能系统由于能够实现电能的时空平移,具有响应速度快,规模化等优点,是改善风电波动性,提高其并网能力的有效手段,构建风储联合发电系统成为目前研究重点.简单介绍了风电并网对电力系统的影响及不同类型电池储能技术的发展现状,给出了部分国内外风储联合发电系统的示范工程,并分析了平滑风电功率波动,跟踪计划出力曲线和削峰填谷3种主要运行方式,重点阐述了目前风储联合发电系统控制策略和储能容量配置研究现状,对进一步开展风储联合发电系统的研究进行了展望,指出经济性仍然是制约储能技术应用的关键问题之一,提高包含储能单元的风储联合发电系统的经济性是今后的研究重点.     

A review on development of offshore wind energy conversion system

Wind energy conversion system, aiming to convert mechanical energy of air flow into electrical energy has been widely concerned in recent decades. According to the installation sites, the wind energy conversion system can be divided into land-based wind conversion system and offshore wind energy conversion (OWEC) system. Compared to land-based wind energy technology, although OWEC started later, it has attracted more attentions due to its significant advantages in sufficient wind energy, low wind shear, high power output and low land occupancy rate. In this paper, the principle of wind energy conversion and the development status of offshore wind power in the world are briefly introduced at first. And then, the advantages and disadvantages of several offshore wind energy device (OWED), such as horizontal axis OWED, vertical axis OWED and cross axis OWED are compared. Subsequently, several major constraints, such as complex marine environment, deep-sea power transmission and expensive cost of equipment installation faced by offshore wind conversion technology are presented and comprehensively analysed. Finally, based on the summary and analysis of some emerging technologies and the current situation of offshore wind energy utilization, the development trend of offshore wind power is envisioned. In the future, it is expected to witness multi-energy complementary, key component optimization and intelligent control strategy for smooth energy generation of offshore wind power systems.     

Dynamic performance of wind-diesel power system with capacitive energy storage

This paper presents an analysis of the dynamic performance of a wind-Diesel power system which operates in isolation from the grid. The simulation studies of the dynamic response are conducted in two different configurations of the power system, firstly, without storage and, secondly, with capacitive energy storage. The frequency and power deviations resulting from a step load disturbance of 1% are presented. It is shown that improvement in the transient responses of the stand alone wind and the hybrid wind-Diesel power system is achieved when capacitive energy storage is included in the systems.     

独立式风光互补发电系统中最大功率控制策略研究

独立风光互补发电系统从能量的角度来看可以分为3部分,即能量获取部分,能量存储部分以及能量消耗部分。主要介绍了能量获取所涉及的风力机最大功率运行和光伏电池最大功率跟踪这2个问题的控制策略,同时对能量存储部分所涉及的蓄电池充放电的控制策略进行了介绍,其中对充电策略的三阶段法做了比较详细的分析。最后对最大功率控制策略的研究方法作了系统的评述并对该领域今后的研究方向作了展望。     

Optimal energy production from wind and hydroelectric power plants

All countries attach great importance to renewable energy investments with concern that future fossil-fueled energy resources could be exhausted. Thus, a very large renewable energy production potential may be predicted in not a very distant future. This study is about optimal energy production from wind and hydroelectric power plants at a small scale settlement center. A water resources system with multiple reservoirs in which wind power plants are located around the basin is described in this study. The system has three scenarios, in which wind and hydroelectric power plants are integrated, separated and no wind turbines. In the integrated scenario, by the energy generated in the wind power plants, the released flows from the reservoirs are sent to the reservoirs as a use again. In models of every scenario, optimal operational models for long-term planning are established on the system. The technique of dynamic programming with successive approximations is used in these models. The models are applied to a water resources system with multiple reservoirs presented successively on the main line of the Ceyhan River in the Ceyhan Basin. The results obtained here are evaluated in terms of three scenarios developed for energy production. As a result, it has been seen that the systems of the integrated and separated scenario are similar to energy productions and system without wind turbines produces more little energy production to other scenarios.     

Design and evaluation of PV-wind hybrid system with hydroelectric pumped storage on the National Power System of Egypt

National and international policies encourage increased penetration of solar and wind energy into electrical networks in order to reduce greenhouse gas emission. Solar radiation and wind speed variations complicate the integration of wind and solar generation into power systems and delay the transition of these sources from centralized to distributed energy sources. The increased penetration of nontraditional energy sources into the electric grid stimulates the demand for large capacities in the field of energy storage. A mathematical model, which describes the operation of a proposed hybrid system, including solar PV, wind energy, and a pumped storage hydroelectric power plant is developed in this paper. This hydropower plant utilizes seawater as a lower reservoir, and only a tank has to be built in order to reduce the installation cost of the storing system. The pumped storage power plant used for compensation of the variation of the output energy from the PV and wind power plants by discharging water from the upper reservoir, which is previously pumped in the case of surplus energy from PV and wind turbine power plants. The impact of the proposed system on the grid utility is investigated in accordance with the values of energy exchange (deficits and surpluses of energy) between the considered hybrid system and the grid. The optimum design is determined by the pump and turbine capacities, upper reservoir volume, and the volume of water left in the tank for emergencies. Different scenarios of the optimum operations are presented for analysis. The results obtained from the examined scenarios indicate the ability of such a hybrid energy system to reduce the exchange of energy with the grid. This paper indicates the technical feasibility of seawater pumped-storage hydropower plant for increasing the Egyptian national grid’s ability to accept high integration of renewable energy sources.     

Autonomous renewable energy conversion system

This paper briefly reviews the need for renewable power generation and describes a medium-power Autonomous Renewable Energy Conversion System (ARECS), integrating conversion of wind and solar energy sources. The objectives of the paper are to extract maximum power from the proposed wind energy conversion scheme and to transfer this power and the power derived by the photovoltaic system in a high efficiency way to a local isolated load. The wind energy conversion operates at variable shaft speed yielding an improved annual energy production over constant speed systems. An induction generator (IG) has been used because of its reduced cost, robustness, absence of separate DC source for excitation, easier dismounting and maintenance. The maximum energy transfer of the wind energy is assured by a simple and reliable control strategy adjusting the stator frequency of the IG so that the power drawn is equal to the peak power production of the wind turbine at any wind speed. The presented control strategy also provides an optimal efficiency operation of the IG by applying a quadratic dependence between the IG terminal voltage and frequency V∼f². For improving the total system efficiency, high efficiency converters have been designed and implemented. The modular principle of the proposed DC/DC conversion provides the possibility for modifying the system structure depending on different conditions. The configuration of the presented ARECS and the implementation of the proposed control algorithm for optimal power transfer are fully discussed. The stability and dynamic performance as well as the different operation modes of the proposed control and the operation of the converters are illustrated and verified on an experimental prototype.