独立运行风力发电系统功率控制器的研究与设计

分析了风能的特性，通过对独立运行风力发电系统的特性和永磁同步电机数学模型的分析与研究，提出了通过调节电磁转矩-转速特性调节功率的一种控制策略，使风力发电机输出在额定风速以下自动跟踪负载用电量。运用此控制笨略采用单片机作为控制芯片，设计了用于控制发电机输出功率的电子调节装置，有效的解决了独立远行小型风力发电系统功率平衡问题。     

液控分布式风力发电并网控制研究

以分布式风力发电系统的工程化应用为背景,基于二次换能原理,对一种液控分布式风力发电并网控制器进行设计和研究,省去了传统的齿轮箱和变流器,实现风力机和发电机之间的柔性连接。以同步电机的数学模型和运行原理以及功率下垂控制策略为基础,设计的并网控制器可以通过调节液压系统的转速来调节有功功率,通过调节电机的励磁电压来调节无功功率。系统实验结果表明,控制策略能够实现对系统输出电能的调整,并且运行性能平稳。     

基于RTDS小步长算法的并网双馈风力发电系统故障仿真研究

为研究并网双馈风力发电系统故障实时运行特性,根据双馈风力发电机并网动态数学模型,在实时数字仿真平台（real time data simulator,RTDS）上搭建基于小步长元件的2 MW双馈式风力发电系统的仿真模型,其“背靠背”变流器采用经典的矢量控制策略。在风力发电系统并网母线故障情况下,分别对风机机械功率与发电机电磁功率的运行特性和背靠背变流器两侧功率及电压等变化情况进行仿真研究。仿真结果表明,故障时基于小步长算法的双馈风力发电系统具有良好的动态性能,同时验证所采用控制策略的有效性。     

交流励磁变速恒频风力发电系统矢量控制研究

基于双馈风力发电机的数学模型和瞬时无功理论,研究了转子侧变换器和网侧变换器的矢量控制策略,提出了双馈风力发电系统从空气动力学系统、机电系统、励磁控制系统完整的模型,以研究系统的暂态特性.以Matlab/Simulink为平台对系统的运行特性进行仿真.仿真结果表明,该控制策略满足变速恒频风力发电系统的要求,可实现最大风能跟踪控制和有功无功功率的独立解耦控制,并可改善系统的低电压穿越能力,实现不脱网运行.     

双馈风力发电系统最大风能追踪控制

在分析风力机功率特性和DFIG运行特性的基础上,通过对双馈机转速控制进行最大风能追踪具体过程的深入研究,提出一种基于最大风能追踪的双馈电机有功、无功功率的解耦控制方法。建立了基于发电机定子磁链定向矢量控制的双馈风力发电系统最大风能追踪系统模型,并利用PSCAD／EMTDC对其进行仿真,结果验证了控制策略的正确性。     

双馈风力发电系统最大风能追踪控制的研究

在分析了风力机功率特性和DFIG运行特性的基础上,通过对双馈机转速控制进行最大风能追踪具体过程的深入研究,提出了一种基于最大风能追踪的双馈电机有功、无功功率的解耦控制方法。建立了基于发电机定子磁链定向矢量控制的双馈风力发电系统最大风能追踪系统模型,并利用PSCAD/EMTDC对其进行仿真,结果验证了控制策略的正确性。     

小型风力发电系统最大功率控制扰动法及状态平均建模与分析

为简化结构、降低成本、提高可靠性及实现系统优化运行,提出了包含永磁同步发电机、二极管整流桥及斩波器的小型风力发电系统结构,采用扰动法来实现最大功率控制,利用状态平均法对系统进行建模,导出了相应的静态特性及线性化模型,给出了扰动幅值及频率这两个关键参数的选取原则,通过实验验证了控制策略及分析方法的正确性和可行性。为最大功率控制扰动法在小型风力发电系统中的应用提供了理论依据,具有重要的理论意义及实际应用价值。     

模糊控制在风力发电系统功率控制中的应用

建立风力发电系统仿真模型,提出应用模糊控制调节风力发电机组输出功率的控制策略.在额定风速以下,采用最佳功率给定法.以追踪最大风能利用系数作为控制目标,提出应用模糊控制器和查表来调节发电机输出功率的方法;在额定风速以上,设计了基于变量化因子的模糊控制器,快速调节风力发电的桨矩角,使输出保持为额定功率.仿真结果证实了该控制策略的有效性,提高了风力发电机组的运行效率.     

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。     

双馈风力发电系统的最大风能控制策略

在分析变速恒频风力发电系统最大风能捕获策略的基础上,提出了一种通过直接控制双馈发电机转子电流就可实现系统低于额定风速下的最大风能捕获又可使得电机铜耗最小化运行的控制策略.首先,在考虑风力机特性和双馈发电机基本电磁关系的基础上,分别推导了双馈发电机定子铜耗最小化运行和最大风能捕获的数学模型.其次,根据双馈发电机最优转子电流的数学模型,建立了双馈风力发电机系统最大风能捕获的控制策略.最后,利用Matlab/Simulink对不同风速下双馈发电机系统的运行性能进行了分析和比较,结果验证了该控制策略的正确性和可行性.     

A sensorless control for a variable speed wind turbine operating at partial load

This paper presents a sensorless control for a variable speed wind turbine (WT) operating at partial load in order to eliminate the direct measurement of the wind speed. In this proposal, the estimated aerodynamic torque is used to determine the optimal reference of the speed control for maximum energy conversion. The maximization of the efficiency on energy conversion and the minimization of detrimental dynamical loads are control trade-offs considered in the design of an optimal discrete-time feedback LQG/LTR controller for the Wind Energy Conversion System (WECS), which is based on the optimization of a quadratic cost function. The performance of the proposed control when the WT is submitted to a gust or step variation on wind speed is evaluated from computational simulations. It is also presented some proposals for sensorless control of the electrical generator.     

Comparative study of speed estimators with highly noisy measurement signals for Wind Energy Generation Systems

This paper presents a comparative study of several speed estimators to implement a sensorless speed control loop in Wind Energy Generation Systems driven by power factor correction three-phase boost rectifiers. This rectifier topology reduces the low frequency harmonics contents of the generator currents and, consequently, the generator power factor approaches unity whereas undesired vibrations of the mechanical system decrease. For implementation of the speed estimators, the compared techniques start from the measurement of electrical variables like currents and voltages, which contain low frequency harmonics of the fundamental frequency of the wind generator, as well as switching frequency components due to the boost rectifier. In this noisy environment it has been analyzed the performance of the following estimation techniques: Synchronous Reference Frame Phase Locked Loop, speed reconstruction by measuring the dc current and voltage of the rectifier and speed estimation by means of both an Extended Kalman Filter and a Linear Kalman Filter.     

风力发电系统输出功率随机波动的仿真分析

针对当前风力发电系统输出功率随机波动的问题,以永磁同步风力发电机(PMSG)与直流侧储能系统(钒氧化还原电池)整合的风力发电系统为基础,进行数字仿真建模,采用MATLAB/Simulink软件对固定负载,变化风速工况;固定风速,负荷瞬变工况;风速和负荷同时变化工况;进行了仿真试验和分析。结果表明,对于采用储能技术的风电场并网功率随机波动的平抑控制,可以利用蓄电池的充放电特性,在风速变化以及负荷瞬变时进行功率平衡的调节。     

Concept study of wind power utilizing direct thermal energy conversion and thermal energy storage

Present wind power is intermittent and cannot be used as the baseload energy source. Concept study of wind power utilizing direct thermal energy conversion and thermal energy storage named Wind powered Thermal Energy System (WTES) is conducted. The thermal energy is generated from the rotating energy directly at the top of the tower by the heat generator, which is a kind of simple and light electric brake. The rest of the system is the same as the tower type concentrated solar power (CSP). The cost estimation suggests that the energy cost of WTES is less than that of the conventional wind power, which must be supported by the backup thermal plants and grid enhancement. The light heat generator reduces some issues of wind power such as noise and vibration.     

变速恒频风力发电系统及其控制技术研究

为了最大限度地利用风能,风力发电系统应采用变速恒频控制策略。分析了鼠笼异步发电系统、双馈发电系统、无刷双馈发电等变速恒频风力发电系统的原理、性能及特点,通过对比各种风力发电机和各种控制方法的优缺点,对未来风力发电机和风力发电控制技术的发展趋势做了展望: 风力发电机大型化;采用变桨距和变速恒频技术;风力发电机采用直接驱动;采用智能化控制等。     

New strategy of pitch angle control for energy management of a wind farm

In this paper, we are interested in a Wind Energy Conversion System (WECS) based on a Permanent Magnetic Synchronous Generator (PMSG). The studied WECS is made by the association of three aerogenerators. The objective of this work is to investigate a new strategy of pitch angle control to ensure a balance between the produced energy and the demanded one by the loads. The control strategy of the wind farm is composed of two parts: a local control according to the characteristics of each wind turbine « Pitch control » to protect the turbines against mechanical failure in the event of wind gust and a global control according to the total power demand and the available wind power. This strategy leads to achieving power objectives (active and reactive power targets) and system constraints.     

一种并网型风光互补发电系统的建模与仿真

分析了风光互补发电系统的技术优势,设计了基于固态变压器结构的并网型风光互补发电系统。分别建立了光伏系统,风力发电系统,超级电容和蓄电池的模型,并分析各环节的控制策略,提出了基于平均功率的储能设备容量配置方法。仿真结果表明,该系统能模拟风光互补系统在不同模式下的运行特性,可以有效降低功率波动和维持电压稳定,并能在低光照强度、低风速等情况下为系统提供短时能量支撑。     

Adaptive back-stepping control for a permanent magnet synchronous generator wind energy conversion system

The maximize energy captured from the wind of a grid-connected variable speed Wind Energy Conversion System (WECS) based on a Permanent Magnet Synchronous Generator (PMSG) is investigated in this paper. An adaptive back-stepping control scheme is applied to achieve maximum power point tracking in the coefficient of maximum power. The features of the proposed control scheme are that it deals with the random nature of wind speed, the uncertainties and external perturbations the acting on WECS effectively, where the bounds of the perturbations are not known in advance. At the same time, a proof of the convergence of the closed-loop system under the proposed controller is derived using the Lyapunov stability theory. Finally, simulations are conducted to illustrate the effectiveness of the proposed approach.     

Multivariable 2-sliding mode control for a wind energy system based on a double fed induction generator

The purpose of this paper is to present a control strategy using Multiple Input/Multiple Output (MIMO) Second Order Sliding Modes (SOSM) for a grid-connected variable-speed Wind Energy Conversion System (WECS). The latter is based on a Double Fed Induction Generator (DFIG) in a bidirectional configuration with slip power recovery. Its points of operation can be electronically controlled and, with them, two independent control objectives can be stated. Thus, a control is designed to maximize the energy captured from the wind and to regulate the stator reactive power, contributing to the compensation of the power factor according to grid requirements.