基于PSCAD的微电网控制系统建模与仿真

为微电网系统的各种高性能控制策略提供有效的动态仿真与分析平台,并克服Matlab仿真环境下所建模型的动态性能方面存在的不足,文章采用PSCAD仿真软件建立了微电网控制系统的动态仿真模型。文章中微电网在并网模式下采用PQ控制,孤岛模式下采用Droop控制。在PSCAD中分别建立控制系统模型,并对处于不同运行模式下的系统进行仿真研究,验证了控制系统模型的有效性。     

基于PSCAD/EMTDC的混合电力有源滤波器建模与仿真分析

有源滤波器是提高电能质量有效的工具之一,介绍了混合电力有源滤波器的结构和工作原理。介绍了瞬时无功功率的谐波电流检测算法,并对滞环电流跟踪控制法、三角载波调制法、无差拍控制方式进行了分析。应用PSCAD/EMTDC搭建了混合电力有源滤波器的仿真模型并进行了仿真实验,结果显示搭建的混合电力有源滤波器的仿真模型有很好的滤波效果。     

并网型风力发电机的建模与仿真

随着风力发电的规模扩大，风电对电网的电压稳定性影响越来越大。文章从电力系统分析的角度建立了以暂态电势为状态变量的风力发电机的机电暂态数学模型，并对该模型进行了仿真试验，验证该模型的正确性。该研究对探讨含风力发电成分的电网的电压稳定性具有一定意义。     

基于MATLAB的并网风电场动态仿真

以并网型风电场为研究对象,建立了异步风力发电系统的动态数学模型,包括风速、风力机、异步发电机以及补偿电容器4部分,其中异步发电机采用三阶模型.利用MATLAB/Simulink建立了仿真系统模型,详细论述了仿真的方法和过程,并对风电场接入电力系统进行了动态稳定分析,验证了采用S函数和Simulink相结合的方法可以有效进行电力系统的分析与计算.同时对如何提高风电系统短路故障后的动态稳定性进行了研究,提出了采用x/r较小的联络线或适当提高电容器的补偿量都有助于提高短路故障后风电系统稳定性的改善措施.     

基于SIMULINK的失速型风电机组软并网控制系统的仿真分析

软并网控制技术是失速型风电机组电控系统的关键技术之一。该文分析了利用晶闸管进行软并网的原理，建立了机组并网的SIMULINK仿真模型，在对仿真模型进行验证的基础上，对各种并网过程进行了仿真，提出了机组并网转速与晶闸管移相触发规律应随电机转子加速度凋节的控制策略，为失速型风电机组软并网系统的研制提供了必要的参考依据。     

基于MMC-HVDC的永磁直驱风机并网控制策略

针对风能的不可控性、间歇性的特点及风电并网后将影响电能质量和电网稳定性的问题,提出了一种基于MMC-HVDC的永磁直驱风机并网控制策略。分别在三相静止坐标系与同步旋转坐标系下建立了MMC-HVDC系统的数学模型,并提出了一种由系统级、换流站级和换流器阀级组成的三层控制策略,以有效控制模块电容电压。在Matlab仿真平台搭建的有源网络和无源网络下的测试结果表明,所提出的风机并网控制策略具有良好的动态响应特性及稳定性,能满足大容量、长距离风机并网的要求。     

光伏电源经新能源同步机并网的仿真研究

针对大规模光伏接入电网带来的稳定性问题,提出光伏电源经新能源同步机MGP并网的解决方法.目前对于MGP的研究仍集中于理论分析与实验室单机模型阶段,尚未得出可用于电磁暂态仿真分析的系统模型.为研究各工况下MGP运行的电磁暂态特性,基于MGP理论研究及同步电机对轴系连接关系,在PSCAD/EMTDC软件中搭建110 kW光...     

风力发电机组并网控制与仿真分析

用仿真方法研究了基于双馈异步发电机的风力发电机组的并网过程,分析了不同因素对发电机并网过程的影响。针对使风力发电机并网时可能产生较大冲击的各种因素,充分利用双馈感应发电机转子励磁的特点,提出了抑制和消除冲击的措施,以实现风力发电机组的快速、平稳并网。     

风力发电系统中组合风速的建模及仿真

在实验室进行风力发电系统模拟,风速模拟是其中重要的一个环节,正确的风速模型不仅可以反应风速实际变化情况,而且能给风力发电系统的模拟研究提供准确的参数。文章采用4分量组合风速模型,用Matlab/Simulink对组合风速进行建模仿真。仿真结果表明,该数学模型能够较精确地反映风速的实际突变性、渐变性及随机性等特点,适用于风力发电系统的模拟研究工作。     

基于DIgSILENT的风电储能系统建模与仿真

针对风电功率的随机波动性,采用储能系统改善风电机组的并网运行特性。文章分析了蓄电池储能系统的基本原理及其控制策略,并基于电磁/机电暂态混合仿真程序DIg SILENT/Power Factory搭建了对应的储能系统模型,将其配置在双馈型风电场出口母线的公共连接点处。分别在风速随机波动以及电网侧发生故障的工况下,研究所建储能系统的动态响应特性,结果表明,储能系统可以减小风电输出功率的波动对电网的影响,并能提高风电场并网的稳定性。     

Stochastic analysis and simulation of grid-connected wind energyconversion system

An increasing presence of renewable energy forms, due to environmental and socio-economic reasons, in the electric power industry necessitates an assessment of the impact of these sources, on a conventional electric utility. This assessment incorporates stochastic theory to investigate the security and stability of a wind energy conversion system (WECS) on an electrical utility to quantify the limits of such a system's operation. This paper presents a model that captures the uncertainties in the system load at the wind generator bus, a method that approximates the randomness experienced by the system. Future dynamic models in development will capture noise due to wind effects. A simple model of a grid-connected WECS is presented. An index of reliability is also determined known as the mean first passage time (MFPT), the time taken for the system to leave its stability region     

基于能量缺失率的并网风电场储能容量优化方法

为平滑风电场输出功率、减少系统振荡,在风电接入时引入储能装置是有效解决方案。文章建立蓄电池的数学模型,以储能装置的全寿命周期成本为目标函数,以风电场发电系统可靠安全运行的限制条件为约束,运用粒子群算法优化配置储能装置容量。最后,通过实际算例验证优化配置算法的有效性与经济性。     

并网风电场最大安装容量分析

介绍了影响风电场最大注入功率的主要因素和分析这一问题的主要方法。同时阐明了衡量风电场建设规模的两个指标:风电穿透功率极限和风电场短路容量比。     

基于数值天气预报的风电功率预测建模研究

基于数值天气预报的支持向量机风电功率预测方法,利用空间分辨率较高的数值天气预报来提高风电功率预测的准确性;通过优化选取NWP的网格点、物理层面及其之上的物理量对预测模型进行简化,提高预测程序的运行速度。采用辽宁省某风场的历史数据,验证了所设计预测算法的有效性,为数值天气预报用于风电功率建模提供了试验支撑。     

基于Matlab的含风电电网建模与仿真

介绍了应用Matlab 7.0对含风电的电网建模以及风速突然变化、系统电压突然下降和电网发生单相接地短路3种情况的仿真分析方法和机理。仿真结果表明，变速风力机驱动双馈式异步风力发电机组的变速平稳。机组效率高，对电网也可以起到一定的稳压和无功调解的作用。     

Reactive power management and control of distant large-scale grid-connected offshore wind power farms

Reactive power management and control of distant large-scale offshore wind power farms connected to the grid through high-voltage alternating current (HVAC) transmission cable are presented in this paper. The choice of the transmission option is based on the capacity of the considered wind farm (WF) and the distance to the onshore grid connection point. The WF is made up of identical doubly-fed induction generators (DFIGs). Modelling and improved analysis of the effective reactive power capability of DFIGs as affected by various operational constraints are provided. In addition, modelling and analysis of the reactive power demands, balance, and control are presented. The minimum capacity and reactive power settings for reactive power compensation required for the system are determined. Possibility of unity power factor operation suggested by the German electricity association (VDEW) is investigated. A summary of the main outcomes of the work presented in this paper is provided in the conclusions section.     

基于瑞利概率分布的风力发电系统中组合风速的改进及建模仿真

风速作为风力发电机组的输入信号,其模拟的正确性直接影响着整个风力发电系统的性能分析与研究。通常计算机仿真所得风速是通过对不同风速的简单组合而实现的某个地区及时间段的平均风速,仿真风速无法体现自然风的多样性。针对此问题,文章提出一种实现自然风的方法。依据某风电场风资源评估报告所给出的风频分布曲线,以瑞利分布规律随机配置各种风速信号,在Matlab/Simulink的运行环境下,仿真出改进的风速,使不同风速随机分配,并且在某个时间段内各种风速出现的概率符合瑞利概率分布。据此方法所得风速更加接近实际自然风,且涵盖从切入风速到切出风速范围内所有风速类型,对风力发电系统的性能分析与研究具有一定的实际意义。     

Using nacelle‐based wind speed observations to improve power curve modeling for wind power forecasting

Wind power forecasting for projection times of 0–48 h can have a particular value in facilitating the integration of wind power into power systems. Accurate observations of the wind speed received by wind turbines are important inputs for some of the most useful methods for making such forecasts. In particular, they are used to derive power curves relating wind speeds to wind power production. By using power curve modeling, this paper compares two types of wind speed observations typically available at wind farms: the wind speed and wind direction measurements at the nacelles of the wind turbines and those at one or more on‐site meteorological masts (met masts). For the three Australian wind farms studied in this project, the results favor the nacelle‐based observations despite the inherent interference from the nacelle and the blades and despite calibration corrections to the met mast observations. This trend was found to be stronger for wind farm sites with more complex terrain. In addition, a numerical weather prediction (NWP) system was used to show that, for the wind farms studied, smaller single time‐series forecast errors can be achieved with the average wind speed from the nacelle‐based observations. This suggests that the nacelle‐average observations are more representative of the wind behavior predicted by an NWP system than the met mast observations. Also, when using an NWP system to predict wind farm power production, it suggests the use of a wind farm power curve based on nacelle‐average observations instead of met mast observations. Further, it suggests that historical and real‐time nacelle‐average observations should be calculated for large wind farms and used in wind power forecasting. Copyright © 2011 John Wiley & Sons, Ltd.