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1.
A critical survey of technologies of large offshore wind farm integration: summary, advances, and perspectives 下载免费PDF全文
Bo Yang Bingqiang Liu Hongyu Zhou Jingbo Wang Wei Yao Shaocong Wu Hongchun Shu Yaxing Ren 《电力系统保护与控制》2022,7(2):233-264
Offshore wind farms (OWFs) have received widespread attention for their abundant unexploited wind energy poten
tial and convenient locations conditions. They are rapidly developing towards having large capacity and being located
further away from shore. It is thus necessary to explore effective power transmission technologies to connect large
OWFs to onshore grids. At present, three types of power transmission technologies have been proposed for large
OWF integration. They are: high voltage alternating current (HVAC) transmission, high voltage direct current (HVDC)
transmission, and low-frequency alternating current (LFAC) or fractional frequency alternating current transmission.
This work undertakes a comprehensive review of grid connection technologies for large OWF integration. Compared
with previous reviews, a more exhaustive summary is provided to elaborate HVAC, LFAC, and five HVDC topologies,
consisting of line-commutated converter HVDC, voltage source converter HVDC, hybrid-HVDC, diode rectifier-based
HVDC, and all DC transmission systems. The fault ride-through technologies of the grid connection schemes are also
presented in detail to provide research references and guidelines for researchers. In addition, a comprehensive evalu
ation of the seven grid connection technologies for large OWFs is proposed based on eight specific indicators. Finally,
eight conclusions and six perspectives are outlined for future research in integrating large OWFs. 相似文献
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Abdelwahab D. Bebars Abdelfattah A. Eladl Gabr M. Abdulsalam Ebrahim A. Badran 《电力系统保护与控制》2022,7(2):265-286
The keys factor in making wind power one of the main power sources to meet the world’s growing energy demands
is the reliability improvement of wind turbines (WTs). However, the eventuality of fault occurrence on WT com
ponents cannot be avoided, especially for doubly-fed induction generator (DFIG) based WTs, which are operating
in severe environments. The maintenance need increases due to unexpected faults, which in turn leads to higher
operating cost and poor reliability. Extensive investigation into DFIG internal fault detection techniques has been
carried out in the last decade. This paper presents a detailed review of these techniques. It discusses the methods that
can be used to detect internal electrical faults in a DFIG stator, rotor, or both. A novel sorting technique is presented
which takes into consideration different parameters such as fault location, detection technique, and DFIG modelling.
The main mathematical representation used to detect these faults is presented to allow an easier and faster under
standing of each method. In addition, a comparison is carried out in every section to illustrate the main differences,
advantages, and disadvantages of every method and/or model. Some real monitoring systems available in the market
are presented. Finally, recommendations for the challenges, future work, and main gaps in the field of internal faults
in a DFIG are presented. This review is organized in a tutorial manner, to be an effective guide for future research for
enhancing the reliability of DFIG-based WTs. 相似文献
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VSC-HVDC transmission system is going to become the most economical way of power delivery for large and remote offshore wind farms. An accurate and fast fault detection method is necessary to protect sensitive devices of these systems and maintain uninterrupted power delivery. This paper investigates an innovative technique for recognizing DC zone faults including HVDC cable faults and unbalancing of DC capacitor bank. Sheath voltage is presented as a novel criterion for detecting abnormal situations in the system. Transient voltage of cable sheath and Wavelet transform are used to identify different types of DC faults. Extensive simulation examples are performed on EMTDC–PSCAD platform and post-processed using MATLAB. The results illustrate that the proposed technique gives a robust performance and can be applied to protection scheme of offshore wind farms. 相似文献
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全功率风电场中机组并网运行的稳定性往往与网侧变流器的控制和并网阻抗有关,因而风电场中机组的失稳并不是同时发生的.为揭示风电场中机组的位置与其暂态稳定性的关系以及机组间稳定性的相互影响,建立了基于锁相环的多风电机组非线性降阶模型.基于等面积法的思想,分析了不同运行条件下风电场内部不同机组的暂态稳定裕度以及场内线路阻抗对稳... 相似文献
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不同风电机组的低电压穿越能力分析 总被引:5,自引:0,他引:5
应用Matlab 7.0建立了含不同风电机组的风电场动态模型,用于研究包含恒速异步风力发电机和双馈异步风力发电机的风电场对电网的影响,通过仿真分析电网发生严重三相短路故障后不同风电机组的低电压穿越能力,以及加装静止无功补偿器(SVC)后风电机组的低电压穿越能力.比较风电机组转速、有功功率和无功功率变化情况,得出结论:双馈异步风力发电机变速平稳,低电压穿越能力较强,有利于优化电能质量.当电网发生故障时,针对风电场中的不同风电机组应采用不同的策略来提高风电机组的低电压穿越能力,维持电力系统的稳定运行. 相似文献
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Xiukun Wei Michel Verhaegen Tim van Engelen 《International Journal of Adaptive Control and Signal Processing》2010,24(8):687-707
This paper aims at the blade root moment sensor fault detection and isolation issue for three‐bladed wind turbines with horizontal axis. The underlying problem is crucial to the successful application of the individual pitch control system, which plays a key role for reducing the blade loads of large offshore wind turbines. In this paper, a wind turbine model is built based on the closed loop identification technique, where the wind dynamics is included. The fault detection issue is investigated based on the residuals generated by dual Kalman filters. Both additive faults and multiplicative faults are considered in this paper. For the additive fault case, the mean value change detection of the residuals and the generalized likelihood ratio test are utilized respectively. For multiplicative faults, they are handled via the variance change detection of the residuals. The fault isolation issue is proceeded with the help of dual sensor redundancy. Simulation results show that the proposed approach can be successfully applied to the underlying issue. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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针对海上风电经柔性直流联网系统受端交流故障导致的直流过电压问题,提出了直流过电压协调抑制策略。针对单极直流过电压,通过合理切换双极MMC控制模式,可使故障极MMC主动维持直流电压稳定。并设计了风电场精确减载控制策略,以保证非故障极MMC满载运行,从而降低单极MMC退出对受端交流电网的影响。针对双极直流过电压,设计了一种基于本地直流电压测量信息的风电场减载控制策略,即根据直流电压变化率及偏差量主动降低风电场有功出力,以抑制直流电压上升率及幅值。并提出了附加桨距角控制及其参数选取原则,使风电场与各换流站内电容共同维持直流电压稳定,提高系统故障穿越能力。最后,基于RTLAB OP5600实时数字仿真平台搭建了系统仿真模型。不同受端交流故障情况下的仿真结果表明,所提直流过电压协调抑制策略可保证直流电压在安全运行范围,维持系统安全稳定运行。 相似文献
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分析了基于H桥换流单元与集中式斩波电阻的多电平集中式卸荷电路(dynamic braking resistor,DBR),介绍了其结构拓扑、参数设计与控制方法,并对比模块化多电平卸荷电路,验证其故障穿越(fault ridethrough,FRT)性能。针对海上风电场并网柔性直流输电系统,结合双馈与永磁直驱风场侧换流站的交流电压降压法,利用风电机组(wind turbine generator,WTG)自身功率调节能力,设计FRT协调控制策略,在保证系统故障穿越性能的前提下,缩减卸荷电路所需容量,适用于高压大容量场合。依据德国已投运Borwin1工程的参数,在PSCAD/EMTDC电磁暂态仿真软件中搭建三端柔性直流输电系统模型,验证了所提协调控制策略具有良好的FRT控制效果。 相似文献
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评价风电机组健康状态,合理分配风电场中风电机组的功率,对降低风电场的运维成本有着重要意义。首先,利用风电机组监控与数据采集(supervisory control and data acquisition, SCADA)系统中的风电机组历史运行数据,训练基于长短期记忆(long short-term memory, LSTM)网络的风电机组输出功率预测模型。然后,根据预测功率和风电机组实测输出功率的偏差幅值将风电机组的健康状态分为良好、一般、较差等三个类别。最后,综合考虑风电场中每台机组的健康状态、最大发电能力和电网调度部门对风电场下达的发电指令,建立目标函数和约束条件,采用遗传算法进行求解,得到分配给每台机组的功率。仿真结果表明,所提出的方法不仅能够根据风电机组的健康状态合理分配机组功率,而且能够满足调度中心下达的风电场总的发电功率。 相似文献
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Fault ride-through capability improvement in a DFIG-based wind turbine using modified ADRC 下载免费PDF全文
In this paper, an overview of several strategies for fault ride-through (FRT) capability improvement of a doubly-fed induction generator (DFIG)-based wind turbine is presented. Uncertainties and parameter variations have adverse effects on the performance of these strategies. It is desirable to use a control method that is robust to such disturbances. Auto disturbance rejection control (ADRC) is one of the most common methods for eliminating the effects of disturbances. To improve the performance of the conventional ADRC, a modified ADRC is introduced that is more robust to disturbances and offers better responses. The non-derivability of the fal function used in the conventional ADRC degrades its efficiency, so the modified ADRC uses alternative functions that are derivable at all points, i.e., the odd trigonometric and hyperbolic functions (arcsinh, arctan, and tanh). To improve the efficiency of the proposed ADRC, fuzzy logic and fractional-order functions are used simultaneously. In fuzzy fractional-order ADRC (FFOADRC), all disturbances are evaluated using a nonlinear fractional-order extended state observer (NFESO). The performance of the suggested structure is investigated in MATLAB/Simulink. The simulation results show that during disturbances such as network voltage sag/swell, using the modified ADRCs leads to smaller fluctuations in stator flux amplitude and DC-link voltage, lower variations in DFIG velocity, and lower total harmonic distortion (THD) of the stator current. This demonstrates the superiority over conventional ADRC and a proportional-integral (PI) controller. Also, by changing the crowbar resistance and using the modified ADRCs, the peak values of the waveforms (torque and currents) can be controlled at the moment of fault occurrence with no significant distortion. 相似文献
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在新能源侧振荡抑制措施失效的情况下,双馈风电场与串补相互作用诱发的次同步振荡会造成大量风机脱网,对系统稳定性产生不利影响。现有振荡抑制措施无法保证在任何情况下都能可靠抑制振荡,因此需要网侧主动对风场进行紧急控制。文中基于频域阻抗判据,针对辐射型网络网侧选切过程中实时计算量过大的问题制定紧急控制策略,以达到降低计算量,减少决策时间的目的。在极坐标系下推导新能源侧频域阻抗实部与支路阻抗模值相角的关系,根据实部变化量分三步进行判断:首先排除"切除无效机组";其次在余下的机组中筛选紧急控制作用有效的机组;最后根据复阻抗量的投影大小确定切除顺序以防过切。基于国内某风电场经串补送出电网实际参数,通过PSCAD仿真试验对所提策略的有效性进行仿真验证,仿真结果表明按照文中所述切除策略进行紧急控制可有效提升系统在次同步振荡过程中的系统阻尼,避免振荡快速发散。 相似文献
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电网故障易造成并网风电场内风力发电机端电压骤变进而导致风力发电机跳闸,威胁风电场的安全运行.提出一种基于模型预测控制(Model Predictive Control,MPC)的风电场故障穿越有功无功优化控制策略.首先,基于下垂控制,根据并网点(Point of Common Coupling,PCC)电压得出故障下的... 相似文献
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In HVDC-connected wind farms with full converter generator (FCG) the short-circuit currents are mainly governed by the control systems of HVDC and wind generators’ converters. This peculiarity requires accurate studies for the design and evaluation of reliable fault detection methods. In line with this need three-phase faults analyses have been performed on a test-case system, using PSCAD/EMTDC, and protection strategies have been proposed and analyzed. 相似文献
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双馈风电场并网运行时,容易发生次同步振荡事故。搭建了双馈风电场经串联补偿电容并网的系统模型,并用Nyquist稳定性判据分析了影响双馈风电场次同步振荡的主要因素。在此基础上,提出了一种基于定子侧模拟电阻的次同步振荡抑制策略,以增强次同步频带下的电气阻尼。时域仿真结果表明该方法能够有效抑制双馈风电场并网系统中的次同步振荡现象,提升系统的稳定性。相较于传统的抑制方法,所提方案无需任何附加装置,便于工程实际应用。 相似文献
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This work presents a power flow strategy for multi-terminal HVDC grids. Energy is mainly generated via renewable energy sources and there are nodes in the network with the possibility to store energy. This energy is generated taking into account real weather conditions in order to make the best scheduling of the system in a realistic approach. An optimization scheme is proposed in which all these elements are included as well as real operation constraints. Distribution losses are minimized for the whole network. This gives as a result a control strategy being able to deal with the whole system and its inherent constraints giving the framework for a multi-objective optimization control. 相似文献
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双馈风电场经柔性直流(VSC-HVDC)并网的振荡数据中蕴含大量信息,这些信息能够反映不确定因素对系统次同步振荡的影响。提出了基于数据驱动的方法分析风速和风电场出口电流波动的不确定因素组合对次同步振荡的影响。首先,对系统振荡数据按风速进行分段,运用基于Nuttall窗插值的FFT识别功率数据中与小信号分析结果相对应的次同步振荡分量并提取幅值。然后,利用高斯混合模型(GMM)聚类算法对因素组合进行聚类,通过三种内部有效性指标评价聚类效果。最后,从次同步振荡分量幅值变化的角度分析了风速/电流波动聚簇对次同步振荡的影响。结果表明:在振荡影响因素组合聚类方面,所提GMM方法相比于K-Means具有更好的聚类效果。当风速/电流波动因素组合属于部分聚簇时,会恶化系统次同步振荡。 相似文献