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几种双馈式变速恒频风电机组低电压穿越技术对比分析 总被引:5,自引:0,他引:5
新电网运行规则要求风力发电机组在电网故障出现电压跌落的情况下不脱网运行,并在故障切除后能尽·陕帮助电力系统恢复稳定运行,要求风电机组具有一定低电压穿越能力。由于双馈感应发电机(DFIG)励磁变换器容量有限,电网故障时会产生转子过电流和变换器直流环节过电压,须实行保护和控制。本文对国内外学术界和工程界对电网故障时双馈感应发电机的保护原理与控制策略进行了大量研究。以便具体设计时根据要求合理选择。 相似文献
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为提高双馈风力发电机在电网电压跌落时的不间断运行能力,提出了双馈风力发电机(DIFG)转子侧变流器无功支持控制策略,并进行了仿真研究。仿真结果表明,该控制方案在不增加硬件成本的基础上提供无功支持,降低了电网压降,减少了直流母线电压波动,提高了双馈风力发电系统的低压穿越能力。 相似文献
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《电子技术与软件工程》2017,(17)
电网中非线性负荷的存在造成电网系统的无功功率不足,也引起电网中大量谐波出现,对电网系统造成越来越多的电能质量问题。静止无功发生器(SVG)通过自换相的电力器件桥式变换器来控制开关的导通与关断时间,以此改变桥式电路交流侧发出或吸收无功功率,能够实时性对电网无功功率进行补偿,提高了电网系统电压的稳定性,也减少了电力系统中谐波的损耗。 相似文献
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二极管箝位型三电平整流器
风电是电力电子应用的典型场合,风力发电机产生的电力全部都是由电力电子电路和控制方法来处理并与电网连接的。其中永磁同步机可以被设计为无外部无功功率源的运行模式。然而,如果电机所需部分磁通可以由外部磁路通过定子绕组提供时,则电机的尺寸可以有效地减少。 相似文献
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电网"晃电"易导致变频器低压跳闸,给连续型生产企业造成严重影响。针对传统DC-BANK系统"晃电"检测智能化程序低,固定压差投切方案不能充分减小投切动作对电机正常工作的影响,设计一种含电网电能质量监测、带自学习功能的投切控制策略。仿真结果表明,新型带自学习功能的DC-BANK系统投切控制器不再局限于单纯依靠对母线电压中东的检测,对电压暂降反应更快。基于该控制器对于母线电压跌落的预判和近压投切能减小固定压差投切对于电机系统正常工作的影响,有利于系统的持续稳定工作,适用于对电能质量要求更高的变频器系统抗"晃电"改造。 相似文献
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本文的主要研究内容为,对于中低压电网的特点及成本要求,我们确立了以TSC为主,并以TCR辅助的控制策略。通过DSPTMS320F2812高速芯片进行多变量计算,发出控制信号到FPGA来驱动TSC投切和TCR连续调节晶闸管相角,这样便能快速跟踪补偿无功功率,而不会产生投切振荡。本控制器的较以往设备的特点为TCR具有可投切功能,避免了TCR中的晶闸管长期并联在电网所引起的干扰与产生大量热量。本课题的选题是由四川省科技厅科技支撑项目"低压终端自动无功补偿装置的研制"。 相似文献
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针对双馈型变速恒频风力发电系统的低电压穿越问题,提出一种新颖的转子侧保护电路。在建立电机的稳态和暂态数学模型的基础上,分析了电网电压发生跌落期间以及电压恢复后的双馈感应发电机的动态响应情况。仿真结果表明,在电压跌落时转子侧加入本文设计的Crowbar电路,能够有效抑制直流侧在电压跌落时电容电压的升高,并能减弱转子侧电流... 相似文献
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在风力发电系统中变速驱动方式的引入给系统带来了许多好处,但是变速风力发电机产生的电能与电网要求的标准不相适应,必须在发电机和电网之间安装电力电子变流器,才有可能将风力能源送入电网。文章主要介绍了在变速风力发电系统中使用的几种不同电力电子变流器的拓扑结构和它们在其它系统中的应用及目前的发展情况。 相似文献
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本文介绍了储能Crowbar和电网电压跌落时的无功需求,在此基础上本文提出了一种新的网侧变流器故障时无功控制策略,仿真验证了控制策略的有效性。接着提出了双馈电机风力发电系统低电压穿越的控制逻辑,在双馈电机风力发电系统仿真平台上运用Matlab/simulink,采用储能Crowbar和故障时无功控制策略以及叶尖速比控制等策略实现了双馈电机风力发电系统的低电压穿越。 相似文献
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大型风电场接入电网可能引起电压闪变和波动、电压暂降、电压偏差以及谐波等电能质量问题。通常对风电场进行无功补偿可以抑制系统电压波动,而轻型直流输电则可以起到无功补偿的作用,抑制并网PCC点电压波动、改善风电场的并网性能。 相似文献
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ABSTRACTThis paper presents a current source inverter (CSI)-based hybrid power generation system, which uses wind turbine and photovoltaic cells (PVs). A permanent magnet synchronous generator (PMSG) is connected to the CSI using a diode rectifier and a buck converter that is used to control the speed of the rotor. Another buck converter is used to control the maximum power point tracking of PVs. The operation of proposed system is studied under normal and grid voltage dip conditions. According to new grid codes, most power generating units are supposed to remain connected to the grid during voltage sag conditions and inject reactive current to grid as defined by grid codes. The CSI has fault current limiting capability that makes it appropriate to use in grid-connected applications and during voltage sag conditions in particular. The proposed system tracks the maximum power point of wind turbine and PVs under normal mode and injects required reactive current to the grid during voltage drop. However, incorporation of CSI with the inherent behaviour of wind turbine and PVs causes fault current to be within the tolerable range for power electronic devices. Simulations are carried out by using PSCAD/EMTDC software to verify the proposed system. 相似文献
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The wind energy generation,utilization and its grid penetration in electrical grid are increasing world-wide.The wind generated power is always fluctuating due to its time varying nature and causing stability problem.This weak interconnection of wind generating source in the electrical network affects the power quality and reliability.The localized energy storages shall compensate the fluctuating power and support to strengthen the wind generator in the power system,in this paper,it is proposed to control the voltage source inverter(VSI)in current control mode with energy storage,that is,batteries across the dc bus.The generated wind power can be extracted under varying wind speed and stored in the batteries.This energy storage maintains the stiff voltage across the dc bus of the voltage source inverter.The proposed scheme enhances the stability and reliability of the power system and maintains unity power factor,it can also be operated in stand-alone mode in the power system.The power exchange across the wind generation and the load under dynamic situation is feasible while maintaining the power quality norms at the common point of coupling.It strengthens the weak grid in the power system.This control strategy is evaluated on the test system under dynamic condition by using simulation.The results are verified by comparing the performance of controllers. 相似文献
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太阳能光伏发电是开发利用新能源的主要形式之一,但是太阳能发电受日出和日落、晴天和阴天等环境因素影响,存在间歇问题,在阴天和雨天因其发电不足会给生产和生活带来诸多不便。为了充分利用太阳能发电,使其能够与公用电网有效互补,文中设计了一种基于户型光伏发电与公用电网互补自动切换系统。该系统由信号比较和开关控制两部分电路组成。信号比较电路用于检测蓄电池最低工作电压,当检测到蓄电池的输出电压低于最低工作电压,系统就自动切换到公用电网;当检测到蓄电池的输出电压高于或等于最低工作电压时,系统就自动切换到太阳能发电系统。 相似文献
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A Fault Tolerant Doubly Fed Induction Generator Wind Turbine Using a Parallel Grid Side Rectifier and Series Grid Side Converter 总被引:3,自引:0,他引:3
With steadily increasing wind turbine penetration, regulatory standards for grid interconnection have evolved to require that wind generation systems ride-through disturbances such as faults and support the grid during such events. Conventional modifications to the doubly fed induction generation (DFIG) architecture for providing ride-through result in compromised control of the turbine shaft and grid current during fault events. A DFIG architecture in which the grid side converter is connected in series as opposed to parallel with the grid connection has shown improved low voltage ride through but poor power processing capabilities. In this paper, a unified DFIG wind turbine architecture which employs a parallel grid side rectifier and series grid side converter is presented. The combination of these two converters enables unencumbered power processing and robust voltage disturbance ride through. A dynamic model and control structure for this architecture is developed. The operation of the system is illustrated using computer simulations. 相似文献
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为了降低大规模风电并网对电力系统的影响,世界各国的电网运营商相继制定新的并网准则对并网风电场的输出特性作出严格规定,并网导则中的一项重要内容是要求风电场具有低压穿越(LVRT)能力。电力电子技术是提高风电场低电压穿越能力的重要手段,对于变速风电机组,电力电子设备已成为其标准配置,在低电压穿越过程中起到至关重要的作用;对于定速风电机组,电力电子设备是使其满足并网导则的必要部件。本文以我国并网导则为例,介绍LVRT导则对风电机组输出特性的相关要求:分析电网电压跌落对不同类型风电机组的影响;在此基础上,针对不同类型的风电机组,介绍提高其LVRT能力的电力电子技术,并对LVRT技术中当前存在的问题和未来的发展方向进行了讨论。 相似文献