多端柔性直流电网故障恢复过/欠电压机理及抑制方法  

Over/Under-voltage Mechanism and Suppression Method for Fault Recovery in Multi-terminal Flexible DC grids

作　　者：李再男 贾科 毕天姝 孙均磊 刘昊霖 LI Zainan;JIA Ke;BI Tianshu;SUN Junlei;LIU Haolin(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(North China Electric Power University),Changping District,Beijing 102206,China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京市昌平区102206

出　　处：《中国电机工程学报》2024年第S01期29-38,共10页PROCEEDINGS OF THE CHINESE SOCIETY FOR ELECTRICAL ENGINEERING

基　　金：国家电网有限公司科技项目(SGZJDK00FZJS2250083)。

摘　　要：多端柔性直流电网在切除故障线路后,各换流站恢复运行模式变化下潮流转移易导致直流过/欠压,危及系统安全运行。针对该问题,基于电网恢复期间直流过/欠电压机理提出对应的抑制控制方法。在电网开环模式恢复下,建立计及潮流方向的线路电压分析模型,探明潮流转移的附加压降是导致过/欠电压本质因素,提出调整电压参考值和降功率相结合的过/欠电压抑制控制方法,有效解决直流过/欠电压问题。测试结果表明,所提方法与传统方法相比,过压峰值降低39.92%、欠压谷值抬升30.46%。After removing the faulted line in a multi-terminal flexible DC grid,the power flow transfer under the change of each converter station’s restoration operation mode is prone to cause DC over/under voltage,which endangers the safe operation of the system.To address this problem,a corresponding suppression control method is proposed based on the DC over/under voltage mechanism during grid recovery.Under the restoration of grid open-loop mode,a line voltage analysis model that considers the direction of the power flow is established.The additional voltage drop caused by the power flow transfer is identified as the essential factor leading to the over/under voltage,and the over/under voltage suppression and control method combining the adjustment of the voltage reference value and the power reduction is proposed to solve the DC over/under voltage problem effectively.The test results show that the proposed method has good over/under voltage suppression performance,which can reduce the peak overvoltage value by 39.92%and lift the under-voltage valley value by 30.46%compared with the traditional method.

关 键 词：多端直流电网 过/欠压机理 过/欠压抑制 参考值调整 降低有功功率 

分 类 号：TM77[电气工程—电力系统及自动化]