摘要
为满足多端柔性直流电网保护的快速性和可靠性要求,提出1种基于故障电流分量的故障识别方案。方案利用故障电流行波分量的传播过程,对区内和区外故障时的电流进行分析,通过故障电流的变化差异对区内外故障进行识别;将双极线路解耦得到线模分量,故障电流线模分量的极性可作方向性判据;用计算得到的正、负极故障电流的平均值之比来实现故障的选极。在PSCAD/EMTDC中建立多端柔性直流输电线路仿真模型,仿真结果表明,所提的故障识别方法无需两端通信,仅利用单端故障电流特征量就能对各种故障进行快速、准确地辨识,且具有一定的抗过电阻能力,满足柔直输电的故障保护要求。
To meet the requirements of fast performance and reliability for multi-terminal modular multi-level converter based high voltage direct current(MMC-HVDC)grid protection,a fault identification scheme based on the characteristics of fault current component is proposed.First,the currents under faults inside and outside of a region are analyzed by using the propagation process of the traveling wave component of fault current,and the inside and outside faults are identified through the difference in changes in fault current.Second,the line-mode component is obtained by decoupling the bipolar line,and the polarity of the line-mode component of fault current can be taken as a direction criterion.Third,the calculated ratio between the averages of positive and negative fault currents is used to realize the fault pole selection.A simulation model of multi-terminal MMC-HVDC transmission line is established in PSCAD/EMTDC,and simulation results show that the proposed fault identification method can identify all kinds of faults quickly and accurately only by using the single-terminal fault current characteristics without the need of two-terminal communication,and it also has the capability of anti-overresistance,thereby satisfying the requirements for MMC-HVDC transmission fault protection.
作者
付华
张辉
FU Hua;ZHANG Hui(Faculty of Electrical and Control Engineering,Liaoning Technical University,Huludao 125105,China)
出处
《电源学报》
北大核心
2025年第5期174-184,共11页
Journal of Power Supply
基金
国家自然科学基金资助项目(51974151,71771111)。
关键词
柔性直流输电
故障识别
故障电流
故障选极
线模电流
Modular multi-level converter based high voltage direct current(MMC-HVDC)transmission
fault identification
fault current
fault pole selection
line-mode current
