Results 11 to 20 of about 3,960 (97)
柔性直流并入城市电网后对换流站近区短路电流的影响研究 [PDF]
大型城市供电电网短路电流已经接近断路器遮断容量,柔性直流接入系统后,会在故障期间提供工作电流,导致交流系统短路电流超标,柔性直流输送功率受限。从柔性直流内外环控制方式及交流系统短路电流计算原理出发,分析得出柔性直流短路电流的幅值和相位对并网点的短路电流影响均较大,其中幅值受外环电流限幅环节的影响易于控制,因此需着重对相位进行控制。基于此提出了一种降低柔性直流输电换流站两端PCC点短路电流的控制策略。以厦门柔性直流工程为例,开发了交直流混合模型,与实测波形对比验证了模型的正确性。通过对不同类型故障下 ...
朱琳, 寇龙泽, 范征, 谷怀广
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欧洲北海等地区已经建设了多条基于柔性直流输电技术的海上风电并网工程,中国近些年也加速了该技术的工程实践。由于柔直系统阻尼低,直流侧暂态过电压、过电流发展快,需要采取必要的暂态应力抑制措施,降低对海上平台设备的技术要求,在尽可能减少设备尺寸的同时,保证足够的设备安全裕度。重点围绕暂态过电压应力,首先总结了海上柔直换流站直流侧暂态过电压应力的类型和关键指标,分别针对对称单极和对称双极结构系统,介绍了直流侧设备上承受过电压应力的机理,并梳理了影响直流侧过电压应力的主要因素。其次 ...
袁艺嘉+4 more
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Research on the Design of Operating Condition of Multi-Resistance Superconducting DC Current Limiter [PDF]
[Introduction] The working principle of the resistive superconducting current limiter is based on the zero resistance effect of the superconductor, which is connected in series in the line and basically has no resistance during normal operation. When the
Jinchuan GUO, Qin YIN
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针对10kV配电线路断路器保护、测量装置需要一般都在电源侧或负荷侧同时接入组合式(电压、电流)互感器。分析了《电业安全工作规程》中规定“带电断接空载线路时,必须确认线路的终端开关[断路器(开关)或隔离开关(刀闸)]确已断开,接入线路侧的变压器、电压互感器确已退出运行后,方可进行。”但是为保证互感器取电正常一般直接接入线路电源侧,而且没有设置控制开关,故无法退出运行。致使无法直接带电断、接带互感器断路器引流线。根据以上问题,本篇文章旨通过对新的作业方法、流程进行研究,在保证不停电情况下退出电压互感器 ...
豪 李+4 more
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Analysis of Current Situation and Future Development of Offshore Wind Power Industry [PDF]
[Introduction] Under the trend of accelerating the clean transformation of coastal energy and adjusting the industrial structure, offshore wind power will become an important support for the safe, clean and efficient transformation of power energy in ...
Jiachang LIU+3 more
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Research on Fault Current Controller of DC Microgrid [PDF]
[Introduction] With the rapid development of AC/DC distribution networks and distributed generation technology, the role of DC microgrids in distribution networks is becoming increasingly important and will become an important component of future ...
Cong LIN, Fang GUO, Xiangfeng LI
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Research on Protection Scheme of DC Microgrid Integrated with Fault Current Limiting Control Technology [PDF]
[Introduction] With the development of new loads, such as distributed power sources and electric vehicles, DC(Direct Current) microgrids have the advantages of fewer commutation links and lower system losses than AC(Alternating Current) microgrids, and ...
Bingyao ZHENG+6 more
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适用于直流配电网故障选线的电力电子变压器分步闭锁方案 [PDF]
级联H桥型电力电子变压器(power electronic transformer with cascaded H-bridge,CHB-PET)是柔性变电站的重要组成设备之一,在直流配电网中具有重要作用。当CHB-PET低压直流侧发生双极短路故障后,故障电流上升速度快且幅值较高,易导致电力电子器件迅速闭锁,使低压直流电网保护难以准确获取故障信息。针对CHB-PET低压侧多分支直流配电网,提出一种基于PET分步闭锁的故障穿越策略。当检测到PET低压侧直流系统故障后 ...
于弘洋+5 more
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Application and Prospect of Flexible Transmission and Distribution Technology in Internet Data Center [PDF]
[Introduction] As an important thrust of China's "new infrastructure", internet data centers have ushered in opportunities for vigorous development and become new areas of energy use, putting forward higher requirements for the power supply level and ...
Deyang CHEN+7 more
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架空线柔性直流电网是实现大规模可再生能源广域协调互补和可靠送出的有效解决方案,是未来高压大容量柔性直流输电的重要应用方向。直流线路短路电流是柔性直流电网中换流阀、直流断路器及电抗器等关键主设备参数选取的重要依据之一。通过建立双极柔性直流电网单个换流站在直流线路不同短路故障类型下的等效电路数学模型,构建了故障时刻双极柔性直流电网等效电路网络模型,提出了一种适用于双极柔性直流电网的单极接地、单极接中性线及双极短路的暂态短路电流定量分析方法,实现了双极柔性直流电网直流线路任意故障类型 ...
裴翔羽+5 more
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