程骁,顾乔根,任旭超,郑超,黄涛,张宝顺
CHENG Xiao,GU Qiaogen,REN Xuchao,ZHENG Chao,HUANG Tao,ZHANG Baoshun

• 1:南京南瑞继保电气有限公司
• 2:国网江苏省电力有限公司

摘要(Abstract)：

海上风电柔性直流输电系统的故障特性有别于常规电力系统，因此常规继电保护方案应用于海上风电柔性直流输电系统时可能存在适应性不足的风险。分析了海上风电柔性直流输电系统故障情形下，不对称的电气量引发的谐波分量以及故障穿越过程中的负序抑制、限流措施对差动保护的影响。推导了计及序分量的差动保护灵敏度计算式并进行适应性分析，指出故障情形下的奇次谐波容易对差动保护产生影响，负序抑制及限流措施也将导致差动保护灵敏度下降。结合实际示范工程的仿真系统进行了大量仿真计算，结果表明，常规差动保护方案的灵敏性、可靠性均存在下降的问题。
The fault characteristics of voltage source converter-based high voltage direct current(VSC-HVDC) transmission systems connected to offshore wind farms differ from those of conventional power systems. Consequently, there exists a potential risk of inadequate adaptability when conventional relay protection schemes are applied to the VSC-HVDC transmission system. This paper analyzes the impact of harmonic components induced by asymmetrical electrical quantities, negative sequence suppression, and current-limiting measures on the performance of differential protection during fault ride-through(FRT). Sensitivity calculation formulas for differential protection considering sequence components are derived, and adaptability analysis is conducted. It is noted that differential protection is susceptible to odd-order harmonics during fault conditions, while negative sequence suppression and current-limiting measures may also diminish its sensitivity. Extensive simulation calculations are carried out using a simulated system of a practical demonstration project. The findings indicate a decrease in the sensitivity and reliability of conventional differential protection schemes.

关键词(KeyWords)： 柔性输电;换流变压器;差动保护;谐波闭锁;灵敏度
VSC-HVDC transmission;converter transformer;differential protection;harmonic blocking;sensitivity

Abstract:

Keywords:

基金项目(Foundation): 国家重点研发计划资助项目（2021YFB2401100）

作者(Author): 程骁,顾乔根,任旭超,郑超,黄涛,张宝顺
CHENG Xiao,GU Qiaogen,REN Xuchao,ZHENG Chao,HUANG Tao,ZHANG Baoshun

DOI: 10.19585/j.zjdl.202403002

参考文献(References)：

• [1]周孝信，陈树勇，鲁宗相，等.能源转型中我国新一代电力系统的技术特征[J].中国电机工程学报，2018,38(7):1893-1904.ZHOU Xiaoxin,CHEN Shuyong,LU Zongxiang,et al.Technology features of the new generation power system in China[J].Proceedings of the CSEE,2018,38(7):1893-1904.
• [2]姚钢，杨浩猛，周荔丹，等.大容量海上风电机组发展现状及关键技术[J].电力系统自动化，2021,45(21):33-47.YAO Gang,YANG Haomeng,ZHOU Lidan,et al.Development status and key technologies of large-capacity offshore wind turbines[J].Automation of Electric Power Systems,2021,45(21):33-47.
• [3]蔡旭，杨仁炘，周剑桥，等.海上风电直流送出与并网技术综述[J].电力系统自动化，2021,45(21):2-22.CAI Xu,YANG Renxin,ZHOU Jianqiao,et al.Review on offshore wind power integration via DC transmission[J].Automation of Electric Power Systems,2021,45(21):2-22.
• [4]王秀丽，赵勃扬，黄明煌，等.大规模深远海风电送出方式比较及集成设计关键技术研究[J].全球能源互联网，2019,2(2):138-145.WANG Xiuli,ZHAO Boyang,HUANG Minghuang,et al.Research of integration methods comparison and key design technologies for large scale long distance offshore wind power[J].Journal of Global Energy Interconnection,2019,2(2):138-145.
• [5]夏嘉航，王晨欣，展瑞琦，等.基于电流源换流器的混合型海上风电直流输电系统[J].电力系统自动化，2021,45(21):129-138.XIA Jiahang,WANG Chenxin,ZHAN Ruiqi,et al.Hybrid DC transmission system for offshore wind power based on current source converter[J].Automation of Electric Power Systems,2021,45(21):129-138.
• [6]孟沛彧，向往，迟永宁，等.一种适用于大规模新能源远距离外送的分层混联输电系统[J].中国电机工程学报，2021,41(10):3349-3363.MENG Peiyu,XIANG Wang,CHI Yongning,et al.A hierarchical LCC-MMC hybrid transmission system for transmitting large-scale renewable power over longdistance[J].Proceedings of the CSEE,2021,41(10):3349-3363.
• [7]袁志昌，郭佩乾，刘国伟，等.新能源经柔性直流接入电网的控制与保护综述[J].高电压技术，2020,46(5):1460-1475.YUAN Zhichang,GUO Peiqian,LIU Guowei,et al.Review on control and protection for renewable energy integration through VSC-HVDC[J].High Voltage Engineering,2020,46(5):1460-1475.
• [8]XUE S M,LIU C.Line-to-line fault analysis and location in a VSC-based low-voltage DC distribution network[J].Energies,2018,11(3):536.
• [9]宋延涛，范雪峰，吴庆范，等.基于MMC的海上风电柔性直流送出控制策略研究[J].高压电器，2023,59(12):63-74.SONG Yantao,FAN Xuefeng,WU Qingfan,et al.Research on flexible DC output control strategy for offshore wind power based on MMC[J].High Voltage Apparatus,2023,59(12):63-74.
• [10]刘一民，王书扬，李彬，等.逆变型新能源场站柔性直流送出系统交流线路差动保护灵敏性优化方案[J].电力建设，2022,43(1):63-69.LIU Yimin,WANG Shuyang,LI Bin,et al.Sensitivity optimization scheme of AC line differential protection in MMC-HVDC system of inverter new energy station[J].Electric Power Construction,2022,43(1):63-69.
• [11]高正创，李凤婷，解超，等.基于电压行波陡度的柔性直流送出线路快速保护方案[J].电力工程技术，2023,42(4):84-93.GAO Zhengchuang,LI Fengting,XIE Chao,et al.Fast protection scheme for flexible DC transmission line based on voltage traveling wave steepness[J].Electric Power Engineering Technology,2023,42(4):84-93.
• [12]刘源，马健，张鑫宇，等.基于边界元件暂态能量变化的直流输电线路纵联保护研究[J].山东电力技术，2023,50(4):58-63.LIU Yuan,MA Jian,ZHANG Xinyu,et al.Research on flexible DC transmission line pilot protection based on transient energy change of boundary elements[J].Shandong Electric Power,2023,50(4):58-63.
• [13]钟启迪，蒲莹，孙建锋，等.适用于柔性直流电网的500 k V级直流电缆与架空线路并联运行控制及保护策略[J].电力建设，2022,43(7):80-86.ZHONG Qidi,PU Ying,SUN Jianfeng,et al.Operation control and protection strategy of domestic 500 k V DCcable in flexible DC grid[J].Electric Power Construction,2022,43(7):80-86.
• [14]黄敏，刘洋，刘合金，等.基于模分量电流相似度的环状柔直配电网线路单极接地故障保护[J].山东电力技术，2022,49(6):44-50.HUANG Min,LIU Yang,LIU Hejin,et al.Single-pole grounding fault protection based on module current similarity for lines in ring shaped flexible DC distribution network[J].Shandong Electric Power,2022,49(6):44-50.
• [15]和敬涵，韦智腾，李猛，等.基于数字孪生的柔性直流线路保护中不良数据自纠错方法[J].电力工程技术，2023,42(6):141-152.HE Jinghan,WEI Zhiteng,LI Meng,et al.A selfcorrecting method for bad data in flexible DC line protection based on digital twinning[J].Electric Power Engineering Technology,2023,42(6):141-152.
• [16]范雪峰，黄金海，宋延涛，等.柔性直流交流连接区故障分析[J].电力系统保护与控制，2020,48(11):151-159.FAN Xuefeng,HUANG Jinhai,SONG Yantao,et al.Fault analysis of flexible DC/AC connection area[J].Power System Protection and Control,2020,48(11):151-159.
• [17]苏见燊，郭敬东，金涛.柔性直流电网中直流故障特性分析及线路故障重启策略[J].电工技术学报，2019,34（增刊1):352-359.SU Jianshen,GUO Jingdong,JIN Tao.Analysis of DCfault characteristics and line fault restart strategy in flexible DC network[J].Transactions of China Electrotechnical Society,2019,34(S1):352-359.
• [18]李国庆，徐亚男，江守其，等.海上风电经柔性直流联网系统受端交流故障穿越协调控制策略[J].电力系统保护与控制，2022,50(7):111-119.LI Guoqing,XU Yanan,JIANG Shouqi,et al.Coordinated control strategy for receiving-end AC fault ride-through of an MMC-HVDC connecting offshore wind power[J].Power System Protection and Control,2022,50(7):111-119.
• [19]贺之渊，陆晶晶，刘天琪，等.柔性直流电网故障电流抑制关键技术与展望[J].电力系统自动化，2021,45(2):173-183.HE Zhiyuan,LU Jingjing,LIU Tianqi,et al.Key technologies and prospect of fault current suppression in flexible DC power grid[J].Automation of Electric Power Systems,2021,45(2):173-183.
• [20]倪斌业，向往，周猛，等.半桥MMC型柔性直流电网自适应限流控制研究[J].中国电机工程学报，2020,40(17):5609-5620.NI Binye,XIANG Wang,ZHOU Meng,et al.Research on adaptive-current-limiting control of VSC-HVDC grid based on half-bridge MMC[J].Proceedings of the CSEE,2020,40(17):5609-5620.
• [21]许冠军，梁营玉，查雯婷，等.方向元件在光伏电站送出线路中的适应性分析[J].电网技术，2019,43(5):1632-1639.XU Guanjun,LIANG Yingyu,ZHA Wenting,et al.Adaptability analysis of directional relay for transmission line out-sending from photovoltaic power plant[J].Power System Technology,2019,43(5):1632-1639.
• [22]梅念，苑宾，乐波，等.对称单极接线柔直系统联结变阀侧单相接地故障分析及保护[J].电力系统自动化，2020,44(21):116-122.MEI Nian,YUAN Bin,YUE Bo,et al.Analysis and protection of single-phase-to-ground fault on valve side of interface transformer in VSC-HVDC system with symmetrical monopolar configuration[J].Automation of Electric Power Systems,2020,44(21):116-122．
• [23]郑涛，邹芃蓥，王子鸣.计及锁相环动态响应特性的光伏并网系统故障电流解析计算[J].电网技术，2022,46(12):4656-4665.ZHENG Tao,ZOU Pengying,WANG Ziming.Fault current analysis of photovoltaic grid-connected system considering dynamic response characteristics of PLL[J].Power System Technology,2022,46(12):4656-4665.
• [24]刘素梅，毕天姝，王晓阳，等.具有不对称故障穿越能力逆变型新能源电源故障电流特性[J].电力系统自动化，2016,40(3):66-73.LIU Sumei,BI Tianshu,WANG Xiaoyang,et al.Fault current characteristics of inverter interfaced renewable energy generators with asymmetrical fault ride-through capability[J].Automation of Electric Power Systems,2016,40(3):66-73.
• [25]徐可寒，张哲，刘慧媛，等.光伏电源故障特性研究及影响因素分析[J].电工技术学报，2020,35(2):359-371.XU Kehan,ZHANG Zhe,LIU Huiyuan,et al.Study on fault characteristics and its related impact factors of photovoltaic generator[J].Transactions of China Electrotechnical Society,2020,35(2):359-371.
• [26]郑涛，黄予园，宗伟，等.光伏并网系统故障二次谐波产生机理及其对变压器保护的影响[J].电力系统保护与控制，2020,48(12):13-22.ZHENG Tao,HUANG Yuyuan,ZONG Wei,et al.Second harmonic generation mechanism of a photovoltaic gridconnected system fault and its influence on transformer protection[J].Power System Protection and Control,2020,48(12):13-22．
• [27]黄涛，王胜利，谢华，等.光伏逆变器短路电流3次谐波及其对保护的影响分析[J].电力自动化设备，2020,40(5):99-108.HUANG Tao,WANG Shengli,XIE Hua,et al.Analysis of third harmonic current of photovoltaic inverter and its influence on protection[J].Electric Power Automation Equipment,2020,40(5):99-108.
• [28]贾科，刘浅，杨彬，等.计及锁相环动态特性的逆变电源故障暂态电流解析[J].电网技术，2021,45(11):4242-4250.JIA Ke,LIU Qian,YANG Bin,et al.Transient fault current analysis of the inverter-interfaced renewable energy sources considering the dynamic characteristics of the phase-locked loop[J].Power System Technology,2021,45(11):4242-4250.
• [29]李彦宾，贾科，毕天姝，等.逆变型电源对故障分量方向元件的影响机理研究[J].电网技术，2017,41(10):3230-3236.LI Yanbin,JIA Ke,BI Tianshu,et al.Influence mechanism of inverter-interfaced renewable energy generators on fault component based directional relay[J].Power System Technology,2017,41(10):3230-3236.
• [30]郑涛，何瑞，刘校销，等.MMC-HVDC系统故障性涌流的产生机理及影响[J].电网技术，2022,46(9):3550-3559.ZHENG Tao,HE Rui,LIU Xiaoxiao,et al.Mechanism of fault-induced inrush current of MMC-HVDC and its influence[J].Power System Technology,2022,46(9):3550-3559.
• [31]吴建云，国兴超，罗美玲，等.逆变侧换流变压器网侧接地故障对差动保护影响分析[J].电力系统保护与控制，2020,48(17):170-178.WU Jianyun,GUO Xingchao,LUO Meiling,et al.Analysis of influence of grounding fault of the network side of an inverter-side converter/transformer on differential protection[J].Power System Protection and Control,2020,48(17):170-178.
• [32]MCGUINNESS S,RUDDY J,PONNALAGAN B,et al.Coordination of AC protection settings during energisation of AC grid from a VSC HVDC interconnector[C]//15th International Conference on Developments in Power System Protection,March 9-12,2020,Liverpool,UK:[s.n.],2020.
• [33]CAO W B,QI X W,ZHANG K J,et al.The impact of the CT saturation on the HVDC protection and its countermeasure[J].IEEE Transactions on Electrical and Electronic Engineering,2017,12(6):834-840.
• [34]陈海荣.交流系统故障时VSC-HVDC系统的控制与保护策略研究[D].杭州：浙江大学，2007.CHEN Hairong.Research on control and protection strategy of VSC-HVDC system when AC system fails[D].Hangzhou:Zhejiang University,2007.