基于最小网损的风电场无功优化分配策略

针对含双馈式风电机组的风电场接入系统维持接入点电压稳定性问题,通过分析通辽某风电场的实测数据,分析其无功补偿特点,提出了基于有功最小的无功优化分配策略;构建了以风力发电机、箱式变压器和集电线路有功损耗最小的无功优化分配目标函数,利用等微增率法对其求解;在考虑风电场有功损耗的前提下,充分利用双馈式风电机组无功调节能力,制定了该风电场无功分配方案。仿真结果表明该策略的可行性,对风电系统的经济运行具有一定的参考价值。     

综合利用SVG和双馈风电机组的风电场无功控制策略分析

针对风电场的无功功率平衡和电压稳定问题,提出了一种以风电场与电网交换无功功值为目标的控制策略。综合运用风电场安装的SVG无功补偿装置及双馈机组的无功调节能力来达到这一目标值。文章结合工程实例,通过对不同发电量下风电场的无功损耗和电压波动情况进行计算,提出利用风力发电机的无功功率可基本实现风电场的无功平衡。     

变速恒频双馈型风电机组在风电场调度控制中的应用研究

本文针对变速恒频双馈型(DFIG)风电机组,建立了基于双馈风电机组自身运行特性的简化模型。在此模型的基础上对双馈异步风电机组有功功率和无功功率的调控能力进行了研究,构建了面向电力系统的动态功率控制方案,充分发挥双馈异步风电机组的灵活调控能力。     

风电机组可靠性建模和动态过程分析

在重点分析双馈感应发电机工作特性的基础上,建立了风电机组可靠性模型,同时对风电机组整个动态过程进行了分析.仿真结果表明风电机组获得最优能量的同时在低风速、额定风速、高风速都具有很好的工作性能.     

一种转子串联可变电阻与卸荷电路配合的低电压穿越方法

针对双馈感应发电机(DFIG)转子串联固定电阻在低电压穿越(LVRT)时,应对故障时的灵活性较低,且低穿效果过于依赖制动电阻的问题,文章提出了转子串联可变电阻与直流侧卸荷电路配合的改进方案。该方案根据转子故障电流的时域表达式对串联阻值进行整定并形成策略表。基于PSCAD/EMTDC仿真不同电压跌落情况下,改进方案的低电压穿越特性。结果表明,文章所提出的方案改善了风电机组的暂态稳定性,有效降低无功损耗,总体上低电压穿越效果较好。     

基于改进粒子群算法含双馈风电机组 配网无功优化研究

针对风电机组并网后对配电网无功补偿产生的影响,从双馈风电机组自身的有功、无功输出特性出发,基于场景概率的方法计算风力机组出力情况,以网损最小为目标函数寻求优化求解方法。利用改进粒子群算法来实现系统接入双馈风电机组后的无功优化,在Matlab 2013b软件中构造IEEE33节点模型并利用该算法求解。结果表明,双馈风电机组在参与系统无功优化时具有良好的性能,验证了该改进算法的有效性     

提升山地风电机组运行质量的策略研究

文章分析了风电机组运行过程中的各种指标,提出了影响风电机组运行质量的关键指标,针对如何提升山地风电机组关键指标提出了应对策略,并对提升机组功率曲线、降低机组故障率进行了应用分析,对提升风电机组运行质量有着重要的意义.     

基于变功率因数的分散式风电场优化运行策略

提出一种考虑负荷类型和风电机组无功极限的分散式风电场优化运行策略。建立基于静态电压特性的典型负荷通用模型;挖掘分散式风电机组无功能力,采用机端并联电容器平衡并提高双馈感应发电机无功调节能力;分析风电机组功率因数对配电网各节点电压、有功和无功网损影响规律;在此基础上,提出基于改进萤火虫算法的分散式风电场最优功率因数运行方法。基于IEEE-33节点模型进行仿真计算,结果表明:分散式风电场小范围功率因数优化调节可有效减小配电网网损,提高电压稳定性。     

基于风电机组无功裕度预测的风电场无功分层控制策略

针对风电电压波动的问题,文章基于风电机组无功裕度预测,提出了一种风电场无功分层控制策略.该策略首先以并网点电压偏差和线路有功损耗最小为目标,使用二次规划算法在线实时求解最优并网电压,进而求解风电场无功参考值;其次,采用EWT-LSSVM预测算法进行风电功率预测,并提出预测功率校正方法实时修正预测功率,精确求解风电机组的...     

基于安全电压的双馈风电机组高电压穿越判别方法

基于双馈风电机组的动态无功支持能力,在电网电压骤升时协调控制网侧变流器和发电机定子输出的无功功率,维持直流侧母线电压的安全稳定运行。根据DFIG直流侧电容的高电压穿越安全要求,定义了电网电压骤升时双馈风力发电机组接入电压的安全电压。然后基于安全电压给出了DFIG在电网电压骤升时能否实现高电压穿越的判断依据,并给出了其高电压穿越时的无功协调输出策略。仿真结果验证了所提的方法。     

Doubly-fed induction generator drive based WECS using fuzzy logic controller

The purpose of this paper is to improve the control performance of the variable speed, constant frequency doubly-fed induction generator in the wind turbine generation system by using fuzzy logic controllers. The control of the rotor-side converter is realized by stator flux oriented control, whereas the control of the grid-side converter is performed by a control strategy based on grid voltage orientation to maintain the DC-link voltage stability. An intelligent fuzzy inference system is proposed as an alternative of the conventional proportional and integral (PI) controller to overcome any disturbance, such as fast wind speed variation, short grid voltage fault, parameter variations and so on. Five fuzzy logic controllers are used in the rotor side converter (RSC) for maximum power point tracking (MPPT) algorithm, active and reactive power control loops, and another two fuzzy logic controllers for direct and quadratic rotor currents components control loops. The performances have been tested on 1.5 MW doubly-fed induction generator (DFIG) in a Matlab/Simulink software environment.     

小型风电系统MPPT模糊／PID控制仿真研究

根据最大功率点跟踪的基本原理及常用风力发电控制系统的特点,提出了一种模糊／PID双模控制。具有在线参数调整的自适应占空比扰动法,该方法同步精度高,动态响应快,能迅速调整发电机与负载之间的功率匹配,减少最大功率点的振荡,使风力机以最佳叶尖速比运行。通过仿真实验表明,采用模糊／PID控制电路,能够快速准确的跟踪风力发电系统的最大功率点,改善最大功率点的振荡,减少能量损失,提高能量转换效率。     

A fuzzy logic pitch angle controller for power system stabilization

In this article the design of a fuzzy logic pitch angle controller for a fixed speed, active‐stall wind turbine, which is used for power system stabilization, is presented. The system to be controlled, which is the wind turbine and the power system to which the turbine is connected, is described. The advantages of fuzzy logic control when applied to large‐signal control of active‐stall wind turbines are outlined. The general steps of the design process for a fuzzy logic controller, including definition of the controller inputs, set‐up of the fuzzy rules and the method of defuzzification, are described. The performance of the controller is assessed by simulation, where the wind turbine's task is to dampen power system oscillations. In the scenario simulated for this work, the wind turbine has to ride through a transient short‐circuit fault and subsequently contribute to the damping of the grid frequency oscillations that are caused by the transient fault. It is concluded that the fuzzy logic controller enables the wind turbine to dampen power system oscillations. It is also concluded that, owing to the inherent non‐linearities in a wind turbine and the unpredictability of the whole system, the fuzzy logic controller is very suitable for this application. Copyright © 2006 John Wiley &Sons, Ltd.     

模糊控制在小型风电系统MPPT中的应用

根据最大功率点跟踪的基本原理及常用风力发电控制系统的特点,提出了一种基于模糊控制、具有在线参数调整的自适应占空比扰动法,该方法能迅速地感知外界的风速变化,调整发电机与负载之间的功率匹配,使风力机以最佳叶尖速比运行.通过Matlab/Simulink仿真实验表明:采用模糊控制电路,风力机的输出功率大幅提高,在风速发生突变的情况下,也能快速地找到新的最大功率点.     

低风速分散式风电并入配电网的双层电压优化模型

从规划和运行2个角度出发,提出一种针对低风速风电机组并入配电网的双层电压优化模型。上层模型计及低风速的波动性、负荷的随机性与用户行为特性,求解以网损、电压偏差、电压稳定性指标和分散式风电总投资为目标函数的多目标规划问题,同时利用Q-V曲线法获得静止无功补偿器(SVC)的最佳接入位置;下层模型建立基于模糊逻辑的低风速风电机组与SVC协调调压的无功控制策略。最后通过仿真验证所提方法不仅能够实现电压优化控制,而且能显著改善配电网的整体电压分布。     

Fuzzy logic control based maximum power tracking of a wind energy system

In this paper a utility interactive wind energy conversion system (WECS) with an asynchronous (AC–DC–AC) link is described. The control system has the objective of identifying and extracting the maximum power from the wind energy system and transferring this power to utility. A fuzzy logic control (FLC) technique has been implemented to design the tracking controller of the WECS. A wind speed step model was used in the design phase. The performance of the WECS with the proposed fuzzy logic controller is tested using real meteorological data. Its robustness and effectiveness are demonstrated by the simulation results of the controlled system.     

超导储能系统提高风电场暂态稳定性研究

应用超导储能系统(SMES)对提高风电场的暂态稳定性进行了研究。在深入研究超导储能系统运行原理的基础上,建立了基于电压型换流器(VSC)的超导储能系统模型,实现了有功功率和无功功率的解耦控制,并提出了有功、无功功率综合控制策略。利用PSCAD/EMTDC软件进行了仿真计算,结果说明超导储能系统不但能够在风速波动时平滑风电场的功率输出,而且能够提高风电系统的暂态稳定性。     

基于遗传算法的风力机叶片优化设计

提出了多次迭代优化设定诱导因子初始值的方法,并以功率输出和年发电量最大为优化目标,在遗传算法的基础上对1.5MW风力机叶片进行了优化设计.为了改善风力机在低风速区域内的输出功率特性,对风轮转速进行了优化.结果表明:优化后,风力机叶片的弦长值得到大幅度的降低,达到额定风速后的功率输出情况也满足了定桨距风力机的功率控制要求,说明该优化方法可以加速搜索寻优过程并保证获得全局最优解;转速优化后,当风力机采用二级转速运行时,年最大输出功率比采用单一额定转速运行时可提高1.16%.     

直驱永磁风力发电系统电网侧变换器的模糊功率控制

针对基于储能的并网永磁直驱风力发电系统的运行特点,提出了一种对电网侧变换器的模糊功率控制策略,当电网发生电压瞬时跌落时使电网侧变换器运行在模糊功率控制模式,依据电网电压跌落深度及风机输出功率大小通过模糊控制器来确定发出无功电流的大小,从而使风电系统能够适度地向电网提供一定的无功功率来支撑电网电压。仿真结果表明,所提出的控制策略正确、有效。     

Enhancement of micro-grid performance during islanding mode using storage batteries and new fuzzy logic pitch angle controller

Power system deregulation, shortage of transmission capacities and needing to reduce green house gas have led to increase interesting in distributed generations (DGs) especially renewable sources. This study developed a complete model able to analysis and simulates in details the transient dynamic performance of the Micro-Grid (MG) during and subsequent islanding process. Wind speed fluctuations cause high fluctuations in output power of wind turbine which lead to fluctuations of frequency and voltages of the MG during the islanding mode. In this paper a new fuzzy logic pitch angle controller is proposed to smooth the output power of wind turbine to reduce MG frequency and voltage fluctuations during the islanding mode. The proposed fuzzy logic pitch controller is compared with the conventional PI pitch angle controller which usually used for wind turbine power control. Results proved the effectiveness of the proposed fuzzy controller in improvement of the MG performance. Also, this paper proposed using storage batteries technique to reduce the frequency deviation and fluctuations originated from wind power solar power fluctuations. Results indicate that the storage batteries technique is superior than fuzzy logic pitch controller in reducing frequency deviation, but with more expensive than the fuzzy controller. All models and controllers are built using Matlab® Simulink® environment.