双馈异步风机非线性低电压穿越控制策略研究北大核心CSCD

针对双馈风力发电机组对低电压穿越能力要求较高的问题,提出一种新型的内电势串级比例积分控制策略。控制器包括电压和功率两个串级控制回路,通过调节内电势dq轴分量,实现双馈风机有功、电压控制,进而完成对有功功率和无功功率的解耦。为提高双馈风机故障穿越能力,引入变增益功角补偿模块,实现故障过程中对功角的完全控制。仿真对比结果验证了该控制策略降低故障中双馈风机端电压跌落程度的有效性。     

适用于双馈风机的并网电压波动与 闪变检测系统的研究

风电因电能质量问题影响使其发展受到制约,电压波动及闪变是其中之一。使用目前的闪变仪对风电机组并网引起电压闪变进行检测,发现在检测低频段波动引起的闪变时误差较大,而这也是风电并网产生闪变的主要频段。因此,如何使低频段检测误差减小是该文研究的意义。根据IEC标准,在Matlab平台建立数字闪变检测系统仿真模型,并利用双线性方法求得系统的参数。针对上述情况,分析其误差产生的原因,通过对检测的瞬时闪变视感度S（t）引入参数校正以减小低频检测误差,使其满足风电并网闪变值检测的要求。最后将修正系数后的检测系统运用在一个双馈风力发电系统实例中,证明该风电场满足我国电压闪变值要求。     

微电网电压/无功协调控制综述

摘要： 简单介绍了微电网控制技术,对微电网电压/无功功率协调控制的基本情况进行了综述。具体给出了几种微电网电压/无功功率基本控制方法,重点介绍了几种微电网电压/无功功率组合控制策略;并对微电网优化控制方法进行了归类;指出了随着微电网的发展,微电网电压/无功协调控制当前存在的问题及有待于深入研究的几个方面。     

基于虚拟同步机的改进双馈风电机组控制策略研究

针对双馈风电机组并网导致风机转速与电网频率相解耦,不及时响应电网频率变化的问题,提出一种基于虚拟定子电压定向的新型双馈风机控制策略。通过改进双馈风机变流器的控制,在风力发电机与电网之间建立起一套虚拟功角,增加了原系统所没有的惯性和阻尼。在稳态时可保障风机运行于最大功率点,当系统发生频率扰动时,可动态地调节风力机组的输出,以响应电网频率的变化。最后,在PSCAD/EMTDC平台上搭建了1.5 MW双馈风机的暂态模型,验证了所提控制策略的有效性。     

双馈风力发电机网侧变换器的统一模糊控制策略

双馈风力发电机网侧变换器通常工作在单位功率因数状态下,未充分发挥出其无功调节潜能。文章分析了双馈风力发电机网侧变换器的无功功率调节极限,针对网侧变换器非线性、时变d-q系统,提出了一种统一模糊控制策略,即利用网侧变换器进行无功补偿,同时抑制因风速变化引起的发电机出口电压波动。在PSCAD/EMTDC环境下,通过无穷大电网末端接入1台2 MW双馈风力发电机进行仿真,验证了该统一控制策略的有效性。     

我国双馈异步风力发电机变流器研制成功

近日，由北京利德华福公司投资成立的北京清能华福风电技术有限公司与清华大学的合作项目1．5MW双馈异步风力发电机变流器研制成功，并一次性通过了兰州电机厂地面满载试验。本次双方合作共同进入风电市场，正是依托利德华福深厚的研发功底、先进的生产工艺以及在电力行业的成熟应用经验，结合清华大学技术、人才领域优势，通过双方长期不懈的努力获得的卓越成果。     

双馈风力发电机网侧变换器的统一模糊控制策略北大核心

双馈风力发电机网侧变换器通常工作在单位功率因数状态下,未充分发挥出其无功调节潜能。文章分析了双馈风力发电机网侧变换器的无功功率调节极限,针对网侧变换器非线性、时变d-q系统,提出了一种统一模糊控制策略,即利用网侧变换器进行无功补偿,同时抑制因风速变化引起的发电机出口电压波动。在PSCAD/EMTDC环境下,通过无穷大电网末端接入1台2 MW双馈风力发电机进行仿真,验证了该统一控制策略的有效性。     

基于SMES协同去磁的双馈风力发电机高电压穿越控制策略

针对风电场双馈感应式发电机(DFIG)在遭受电网电压暂升扰动而脱网运行的问题,从DFIG在暂升扰动下定子磁链暂态行为出发,分析磁链序分量在转子侧相互叠加导致DFIG难以完成高电压穿越(HVRT)的机理过程,为解决传统去磁控制存在裕度有限不能应对严重暂升扰动,且响应时间缓慢问题,提出了超导磁储能系统(SMES)协同去磁控...     

双馈风机磁链暂态特性分析及Crowbar电路的改进

基于双馈感应风力发电机两相静止坐标系下的数学模型,推导了电压跌落和恢复过程定转子磁链的表达式,并利用空间矢量图分析了磁链的变化规律。当故障持续时间较短,且电压恢复时刻为半工频周期的奇数倍时,电压恢复时的过电流较电压跌落时更为严重。针对这一问题,对Crowbar电路的结构及控制策略进行了改进。通过PSCAD/EMTDC仿真软件验证了理论分析和改进方案的合理性。     

基于dSPACE的电网谐波环境下双馈风机的适应性分析

文章以双馈电机(DFIG)机组及以含有5,7,11,13次谐波电压的电网为研究对象,针对风电机组应对电网谐波带来的扰动并维持正常运行等问题进行了研究。给出了一种基于多重谐振控制器的谐波抑制方法,并在dSPACE仿真平台上建立了一台2 MW风机模型,借助dSPACE系统提供的ControlDesk环境对其进行实时仿真分析。实时仿真结果表明,该方案能有效减少5,7,11,13次电网谐波电压带来的影响,使DFIG定子电流波形更加正弦化,改善直流母线电压波动问题,提高了电网谐波环境下风机系统的适应性。     

A new control strategy for a stand-alone self-excited induction generator driven by a variable speed wind turbine

This paper presents a new control strategy of a stand-alone self-excited induction generator (SEIG) driven by a variable speed wind turbine. The proposed system consists of a three phase squirrel-cage induction machine connected to a wind turbine through a step-up gear box. A current controlled voltage source inverter (CC–VSI) with an electronic load controller (ELC) is connected in parallel with the main consumer load to the AC terminals of the induction machine. The proposed control strategy is based on fuzzy logic control principles which enhance the dynamic performance of the proposed system. Three fuzzy logic PI controllers and one hysteresis current controller (HCC) are used to extract the maximum available energy from the wind turbine as well as to regulate the generator terminal voltage simultaneously against wind speed and main load variations. However, in order to extract the maximum available energy from the turbine over a wide range of wind speeds, the captured energy is limited due to electrical constraints. Therefore the control strategy proposed three modes of control operation. The steady state characteristics of the proposed system are obtained and examined in order to design the required control parameters. The proposed system is modeled and simulated using Matlab/Simulink software program to examine the dynamic characteristics of the system with proposed control strategy. Dynamic simulation results demonstrate the effectiveness of the proposed control strategy.     

双馈感应风力发电系统电流控制策略研究

由双馈发电机q-d坐标系下基本数学模型,推导出双馈发电机的转子电流和转子电压、磁链之间的关系模型。文章研究了双馈风力发电系统转子侧电流控制策略框图,计算选择PI控制器参数。利用MATLAB/SIMULINK平台自行建立了1.5 MW风力发电系统整体仿真模型。运行该系统模型,得到了双馈发电机转子电流、电压,滤波器输出电流及定子电压等信号波形曲线。仿真结果验证模型及控制器的正确性,证明PI控制器能够满足双馈风力发电系统的稳、准、快等性能指标。     

Modeling and control of a wind turbine driven doubly fed induction generator

This paper presents the simulation results of a grid-connected wind driven doubly fed induction machine (DFIM) together with some real machine performance results. The modeling of the machine considers operating conditions below and above synchronous speed, which are actually achieved by means of a double-sided PWM converter joining the machine rotor to the grid. In order to decouple the active and reactive powers generated by the machine, stator-flux-oriented vector control is applied. The wind generator mathematical model developed in this paper is used to show how such a control strategy offers the possibility of controlling the power factor of the energy to be generated.     

Analysis of a fuel cell micro-grid with a small-scale wind turbine generator

If electric power is supplied using an independent micro-grid connected to renewable energy, it can flexibly match the energy demand characteristics of a local area. And an independent micro-grid is expected to be effective in cutting greenhouse gas discharge and energy costs, as well as in eliminating the need for an emergency power supply system. Since the output of renewable energy is unstable, other energy equipment needs to cover the stability of output. Thus, the operating conditions of an independent micro-grid that supplies power with natural power sources and fuel cells are investigated. The operation conditions of a fuel-cell independent micro-grid with wind power generation were investigated by numerical analysis. Step loads and an apartment house power load model were analyzed using the dynamic characteristics of a fuel cell obtained from experiments. The output of wind power generation and fuel cells is controlled by proportional-integral control of an independent micro-grid for rapid power demand change.     

Transient and dynamic control of a variable speed wind turbine with synchronous generator

In this article, a controller for dynamic and transient control of a variable speed wind turbine with a full‐scale converter‐connected high‐speed synchronous generator is presented. First, the phenomenon of drive train oscillations in wind turbines with full‐scale converter‐connected generators is discussed. Based on this discussion, a controller is presented that dampens these oscillations without impacting on the power that the wind turbine injects into the grid. Since wind turbines are increasingly demanded to take over power system stabilizing and control tasks, the presented wind turbine design is further enhanced to support the grid in transient grid events. A controller is designed that allows the wind turbine to ride through transient grid faults. Since such faults often cause power system oscillations, another controller is added that enables the turbine to participate in the damping of such oscillations. It is concluded that the controllers presented keep the wind turbine stable under any operating conditions, and that they are capable of adding substantial damping to the power system. Copyright © 2007 John Wiley & Sons, Ltd.     

Review of contribution to frequency control through variable speed wind turbine

The increasing wind penetration in today’s power grids has led to growing interest in the frequency control capabilities of wind generation. Several publications have proposed a variety of methods both on the levels of a single turbine and of a wind farm. This paper focuses on the role of wind generation in a system’s primary frequency control. Wind turbine control methods that enable frequency support and control are presented. The advantages and disadvantages of each method are discussed.     

并网双馈风力发电机矢量控制的改进及实现

分析了传统的双馈风力发电控制策略,并在网侧变换器和转子侧变换器中分别使用了电网电压定向和转子侧定子磁链定向的矢量控制.传统的控制策略比较复杂,对其提出了改进方案,改进后的控制方法大大简便.利用PSCAD/EMTDC平台进行仿真表明,改进后的控制方案是正确的.     

Experimental study of variable speed wind generator contribution to primary frequency control

The work presented in this paper analyses, with the help of experiments on a 2.2 kW test bench, the possibility to participate in the primary frequency control with a variable speed wind generator. A power reserve is obtained with the help of the generator torque control by following a power reference value lower than the maximum power which must be extracted from the wind. This approach allows also using a part of the kinetic energy in the blades inertia to contribute to this reserve.The dynamic tests carried out on the test bench, by using medium and high variable wind speeds, confirm the capacity of the wind turbine generator (WTG) to participate in the primary frequency control.     

孤岛双馈异步风力发电机组自抗扰控制研究

针对孤岛运行双馈异步风力发电机输出电压易受负载切换影响、PI控制器对电机参数依赖性高等问题,建立了包含励磁电流动态过程与电机参数误差的数学模型。将电机参数误差和励磁电流动态过程分别视为系统的内扰与外扰,应用分离性原理和零极点配置方法设计双闭环自抗扰控制器替代PI控制器,扩张状态观测器可实时估计系统总扰动,并通过前馈进行补偿。建立兆瓦级DFIG孤岛运行仿真模型进行验证,结果表明文章控制方法能够有效抑制负载切换引起的电压扰动和电机参数变化的影响,提高了系统抗扰动性能。     

变速变桨风力发电机组的优化控制

提出了大型变速变桨风力发电机组在不同控制阶段的优化控制策略。在低风速时,采用自适应转矩控制方式,实现机组的变速运行,追踪最佳风能利用系数。在额定风速以上时,为了解决传统桨距控制方式系统超调量大的问题,提出了一种新型气动转矩观测器,并将气动转矩与发电机转矩偏差输入控制器。通过Bladed外部控制器模块编程并进行仿真,结果表明,所提出的控制策略能够更好地追踪最大功率点,并改善桨距控制效果,稳定功率输出。