考虑磁路饱和及集肤效应的异步风力发电机组暂态性能分析

为准确分析异步发电机不同详细模型对大型风电机组暂态性能的影响,该文结合2个质量块的风力机传动链等效模型,分别建立了笼型异步发电机考虑主磁路、定转子漏磁路饱和以及集肤效应影响的风电机组数学模型。针对大型风电机组在机械大扰动和电网电压骤降情况下,利用Matlab/Simulink平台对机组在不同数学模型描述时的暂态过程进行了仿真比较。结果表明,尤其在电网电压骤降时,电机磁路饱和对机组暂态运行性能的影响较为显著。     

恒速风电机组对电网暂态电压稳定性的影响

基于恒速风电机组的结构,给出风电机组各部分的数学模型,利用仿真软件DIgSILENT/PowerFactory建立恒速风电机组的动态模型,并利用该模型在WSCC 3机9节点算例中仿真恒速风电机组并网运行时因风速变化引起的电网电压波动,通过极限切除时间分析恒速风电机组并网对电网暂态电压稳定性的影响,并与接入相同容量的同步机组进行比较。结果表明,恒速风电机组的接入降低了电网的暂态电压稳定性,且接入恒速风电机组装机容量越大,电网的暂态电压稳定性越差。由此提出改善恒速风电机组并网后电网暂态电压稳定性的建议。     

风电系统的无功功率与电网电压稳定

论述了风电容量在占局部电网相当比例时,风电机组的无功功率调整与电网电压之间的关系,对于定速和变速风电机组的运行特性做了分析,提出了在需要做无功功率调整时风电机组应能满足的特殊要求。     

风电机组高电压穿越技术研究

随着风电入网比例的增大,风电入网导则也逐步发展建立,入网导则的主要目的是确保风电场的入网运行不影响整个电力系统的稳定。风电场低电压穿越(LVRT)已作为热点技术被广泛关注,但风电机组风电场高电压穿越没有得到相应的重视。文章基于常见机组类型,首先介绍了风电机高电压穿越(HVRT)方面现有电网要求,给出了现有风电场高电压穿越能力要求曲线,对风电机组高电压穿越软硬件的技术方案。最后仿真证明了所提技术方案的正确性,分析了该技术方案对风机运行成本方面的可行性。     

风电场无功功率/电压控制与管理问题探讨

正随着风电比例的日益增长,如中国酒泉地区、新疆哈密地区等风电场群大规模集中接入电网并高电压远距离外送案例的不断增加,风电在电力系统中的"地位"在发生变化,风电对电网的影响已经不可忽视,其中风电场的无功功率/电压控制问题尤为突出,电压控制问题影响着整个区域电力系统的安全稳定性和区域电网的运行经济性。目前市场上流行的风电机组都具备一定的无功调节能力,大多数风电场在其主变低压侧配置了集中型无功功率补偿装置,并实现了风电场的电     

风电机组低电压穿越能力影响因素分析与实例

我国风电大规模汇集地区多处于电网末端,电压波动性强,随着对风电并网安全的关注和风电机组并网性能要求的提高,低电压穿越能力已成为衡量风电机组并网性能的重要指标。文章调研了同一区域内多个风电场实际运行中的低电压穿越故障情况,分析了整机制造厂家、高校及相关研究机构对风电机组低电压穿越技术的研究现状。通过分类统计测试过程中遇到的风电机组低电压脱网故障和总结56台风电机组的低电压穿越测试结果,分析了造成风电机组低电压穿越能力不足的原因,并对引起风电机组低电压穿越能力不足的影响因素进行了阐述。目前,软件版本控制、保护定值的设置与管理、硬件的维护水平已经成为并网风电机组低电压穿越能力的主要影响因素。     

变速风电机组仿真用数学模型研究

针对变速风电机组仿真用数学模型进行了研究。介绍了变速风电机组各种发电机的仿真数学模型以及机组运行控制策略、发电功率输出控制策略和电网负荷等建模。该模型能对风电机组设计起到指导作用。     

双馈风电机组接入地区电网后的电压稳定分析

利用PSASP软件的UPI接口程序模块．在PSASP中建立了双馈风电机组模型,以两个实际的地区电网为例,研究双馈风电机组接入地区电网后对电网电压的影响,结果表明：双馈风电机组提高了地区电网的静态电压水平：双馈风电机组在故障后能够减少系统所需的无功储备,从而有利于地区电网的电压稳定;风速的波动对地区电网的电压有影响,但一般不会影响其暂态稳定性。     

考虑风电机组故障穿越特性的电压反复波动机理分析与抑制

近年来,大规模风电汇集系统实际运行中频繁出现电压反复波动现象,具有波动幅度大、波动峰谷值切换速率达秒级的特点,与风能随机性、无功补偿装置动作引起的电压波动现象具有显著区别,运行中多次造成风电机组因连续穿越失败而脱网,严重威胁了电网安全稳定运行。上述现象涉及风电机组故障穿越策略与弱电网功率-电压特性的耦合作用,难以通过传统电力系统电压稳定分析方法直接解释。提出了考虑风电机组低电压穿越特性的系统有功-电压曲线（PV曲线）分析方法,准确刻画波动过程中系统运行点轨迹变化规律,并通过仿真进行了验证。在此基础上,提出了抑制电压反复波动的风电机组低电压穿越优化控制策略,基于实际算例的仿真分析表明,提高风电机组退出低电压穿越阈值及采用穿越期间维持有功的策略可以有效抑制电压反复波动现象。     

双馈异步风电系统的建模仿真

当电网电压跌落时,风电机组须维持一定时间与电网连接而不解列,并且能提供无功以支持电网电压的恢复,即具有低电压穿越能力,而双馈风电机组低电压穿越能力最弱。分析建立了双馈风力发电机组的模型,通过使用MATLAB/SIMULINK仿真,来研究它的LVRT性能,及影响它LVRT性能的因素,探讨它的改进方案。     

陕西省金润河北镇风电场风能资源开发评估

对陕西省宝鸡市陇县金润河北镇风电场气象条件、风功率密度、平均风速、主导风向等风能参数进行分析评价。结果表明,测风塔100 m高度月平均风速、月平均风功率密度最大均出现在4月,最小均出现在8月;测风塔100 m高度主导风向为SSW(南西南),主要风能方向为SSW(南西南),风电场风功率密度等级为1级。风电场安装20台2500 kW的风电机组,装机容量50 MW,年设计发电量1.33485×108 kW·h,年出厂电量9.5426×107 kW·h。结果可为其他风电场选址和发电量估算提供参考。     

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.     

基于风电机组可靠性的风电场平准化成本模型研究

考虑综合风电场总体运行成本、风电机组可靠性及风电场发电量等多个维度,从风电场全生命周期视角出发,建立基于风电机组可靠性的风电场平准化成本模型,并通过算例分析得出,提升风电机组可靠性可降低风电机组的故障维护成本,提高风电场运行小时数,进而降低风电场平准化成本。在此基础上测算当前阶段风电实现平价上网需达到的利用小时数,最后给出促进风电发展的合理化建议。     

Investigation of wind energy potentials in Brunei Darussalam

Conventional power generation mainly depends on natural gas and diesel oil in Brunei Darussalam. The power utility company is now thinking of power generation using natural wind. In this paper, wind energy, being one of the most readily available renewable energy sources, was studied. The wind characteristic, velocity and directions were studied using Weibull distribution based on the measurement of wind speed at two different locations in Brunei Darussalam. These wind speed distributions were modeled using the Wind Power program. The wind rose graph was obtained for the wind direction to analyze the wind power density onshore and offshore. Based on this analysis, it has been found that the wind speed of 3 to 5 m/s has a probability of occurrence of 40%. Besides, the annual energy production at a wind speed of 5 m/s has been found to be in the range between 1000 and 1500 kWh for both the locations in Brunei Darussalam.     

A new formulation for rotor equivalent wind speed for wind resource assessment and wind power forecasting

The spurt of growth in the wind energy industry has led to the development of many new technologies to study this energy resource and improve the efficiency of wind turbines. One of the key factors in wind farm characterization is the prediction of power output of the wind farm that is a strong function of the turbulence in the wind speed and direction. A new formulation for calculating the expected power from a wind turbine in the presence of wind shear, turbulence, directional shear and direction fluctuations is presented. It is observed that wind shear, directional shear and direction fluctuations reduce the power producing capability, while turbulent intensity increases it. However, there is a complicated superposition of these effects that alters the characteristics of the power estimate that indicates the need for the new formulation. Data from two field experiments is used to estimate the wind power using the new formulation, and results are compared to previous formulations. Comparison of the estimates of available power from the new formulation is not compared to actual power outputs and will be a subject of future work. © 2015 The Authors. Wind Energy published by John Wiley & Sons, Ltd.     

一种用激光方法改进风机对风精度的研究

功率曲线是风力发电机组的设计依据,也是考核机组性能、评估机组发电能力的一项重要指标。结合目前已经出现的功率曲线问题的综合分析来看,风机对风精度是影响功率曲线的关键因素之一。现今的风机基本都是利用风向标来进行风机对风。文章通过对现在大量使用的风向标与风机找零方式进行分析研究,提出了一种不受天气、光线影响,更加精确、方便的风向标与风机之间的找零方法,提高了风机对风精度,大大改善了风机的功率曲线。     

计及随机波动风速、风向的风电场建模方法研究

提出风电场建模方法建立风电场随机模型,对风电场运行特性进行仿真,为实现大规模风力发电的可预测、可控制目标服务。通过对风电场等值模型与详细模型的仿真比较,验证建模方法的合理性,并得出在研究风电场动态特性及其对电网影响时应考虑风速、风向的随机波动建立风电场模型。     

风电供暖技术方法研究

风电供暖对于提供风电场运行效率具有重要意义。根据风电场的实际情况选用合适的供暖方案,可以有效地减轻和避免风电场对电力系统的不利影响,同时提高了风电场在电力市场中的竞争能力。重点分析了离网型风电机组独立供暖、风电互补供暖、风光互补供暖、风电和燃气联合循环机组供暖等几种基本方法。     

风切变对大直径风力机风轮输出功率影响的初探

以风切变幂指数为0．14的风廓线模型进行了风轮输出功率计算,并与以风轮中心风速计算风轮功率进行了对比分析,指出风切变对风轮输出功率的影响不容忽视。     

On the wind power rejection in the islands of Crete and Rhodes

Crete and Rhodes represent the two biggest isolated power systems in Greece. The energy production in both islands is based on thermal power plants. The annual wind energy rejection percentage is calculated for Crete and Rhodes in this paper. The rejected wind energy is defined as the electric energy produced by the wind turbines and not absorbed by the utility network, mainly due to power production system's stability and dynamic security reasons. A parametric calculation of the annual wind energy rejection percentage, in terms of the installed wind power, the power demand and the maximum allowed wind power instant penetration percentage, is accomplished. The methodology takes into account (i) the wind power penetration probability, restricted by the thermal generators technical minima and the maximum allowed wind power instant penetration percentage over the instant power demand; and (ii) the wind power production probability, derived by the islands' wind potential. The present paper indicates that isolated power systems which are based on thermal power plants have a limited wind power installation capacity—in order to achieve and maintain an adequate level of system stability. For a maximum wind power instant penetration percentage of 30% of the power demand, in order to ensure an annual wind energy rejection percentage less than 10%, the total installed wind power should not exceed the 40% of the mean annual power demand. The results of this paper are applicable to medium and great size isolated power systems, with particular features: (i) the power production is based on thermal power plants; (ii) the power demand exhibits intensive seasonal variations and is uncorrelated to the wind data; (iii) the mean annual power demand is greater than 10MW; and (iv) a high wind potential, presenting mean annual wind velocity values greater than 7·5ms^?1, is recorded. Copyright © 2007 John Wiley &Sons, Ltd.