Abstract:Due to various distances of transmission lines as well as higher resistance for the voltage source converter multi-terminal direct current (VSC-MTDC)system,the copper loss for the whole system,especially the long distance and large capacity high voltage direct current (HVDC) system,is larger.In order to realize the coordinated control between different stations achieving the minimum copper loss for the HVDC system,the calculation method of the voltage droop coefficient for the VSC-MTDC system without/with local load is built,and a DC voltage droop control strategy is proposed.By introducing the remaining capacity space,each converter station can participate in the power compensation according to its remaining capacity.The PSCAD/EMTDC is used to build the detailed models of the VSC-MTDC system.The simulation verifies operating characteristics in normal/fault conditions.Simulation results show that the proposed control can reduce the copper loss effectively,restrain the DC power oscillation caused by AC fault,and realize the emergency power support.
冉晓洪, 苗世洪, 吴英杰, 钱甜甜. 基于最优功率分配的多端直流网络改进下垂控制策略[J]. 电工技术学报, 2016, 31(9): 16-24.
Ran Xiaohong, Miao Shihong, Wu Yingjie, Qian Tiantian. An Improved Droop Control Strategy for Multi-Terminal DC Grids Based on Optimal Active Power Allocation. Transactions of China Electrotechnical Society, 2016, 31(9): 16-24.
[1] 文劲宇,陈霞,姚美齐,等.适用于海上风场并网的混合多端直流输电技术研究[J].电力系统保护与控制,2013,41(2):55-61. Wen Jinyu,Chen Xia,Yao Meiqi,et al.Offshore wind power integration using hybrid multi-terminal HVDC technology[J].Power System Protection and Control,2013,41(2):55-61. [2] 陈霞,林卫星,孙海顺,等.基于多端直流输电的风电并网技术[J].电工技术学报,2011,26(7):60-67. Chen Xia,Lin Weixing,Sun Haishun,et al.LCC-MTDC technology for wind farms integration[J].Transactions of China Electrotechnical Society,2011,26(7):60-67. [3] 邓旭,王东举,沈扬,等.舟山多端柔性直流输电工程换流站内部暂态过电压[J].电力系统保护与控制,2013,41(18):111-119. Deng Xu,Wang Dongju,Shen Yang,et al.Research on transient overvoltage for converter station of Zhoushan multi-terminal VSC-HVDC project[J].Power System Protection and Control,2013,41(18):111-119. [4] 傅晓帆,周克亮,程明.近海风电场并网用多端口VSC-HVDC系统的无差拍协同控制策略[J].电工技术学报,2011,26(7):51-59. Fu Xiaofan,Zhou Keliang,Cheng Ming.Synergy Dead-beat control scheme for multi-terminal VSC-HVDC systems for grid connection of off-shore wind farms[J].Transactions of China Electrotechnical Society,2011,26(7):51-59. [5] 范心明,管霖,夏成军,等.风电场交直流混合输电并网中VSC-HVDC的控制[J].中国电机工程学报,2014,34(28):4781-4790. Fan Xinming,Guan Lin,Xia Chengjun,et al.Control of VSC-HVDC in AC/DC hybrid transmission with wind farms integrated[J].Proceedings of the CSEE,2014,34(28):4781-4790. [6] 王珂,刘建涛,李亚平,等.柔性直流输电系统的自适应下垂反馈控制方法[J].电力系统控制与保护,2014,42(9):48-53. Wang Ke,Liu Jiantao,Li Yaping,et al.An adaptive power control strategy based droop feedback for VSC-HVDC[J].Power System Protection and Control,2014,42(9):48-53. [7] Nakajima T,Irokawa S.A control system for HVDC transmission by voltage sourced converter[C]//IEEE Power Engineering Society Summer Meeting,Edmonton,Canada,1999:1113-1119. [8] 阮思烨,李国杰,孙元章.多端电压源型直流输电系统的控制策略[J].电力系统自动化,2009,33(12):57-61. Ruan Siye,Li Guojie,Sun Yuanzhang.A control strategy for multi-infeed VSC-HVDC systems[J].Automation of Electric Power Systems,2009,33(12):57-61. [9] Yao L,Xu L,Bazargan M,et al.Multi-terminal HVDC grid for network interconnection and renewable energy integration[C]//CIGRE Session,Paris,France,2010:1-9. [10]唐庚,徐政,刘昇.适用于多端柔性直流输电系统的新型直流电压控制策略[J].电力系统自动化,2013,37(15):125-132. Tang Geng,Xu Zheng,Liu Sheng.A novel DC voltage control strategy for VSC-MTDC system[J].Automation of Electric Power Systems,2013,37(15):125-132. [11]Bellmunt O G,Liang J,Ekanayake J,et al.Topologies of multi-terminal HVDC-VSC transmission for large off-shore wind farms[J].Electric Power System Research,2011,81(2):271-281. [12]Hendriks R L,van der Meer A A,Kling L W.Impact on system stability of different voltage control schemes of wind power palts connected through AC and VSC-HVDC transmission[C]//Proceedings of the Nordic Wind Power Conference,Denmark,2009. [13]Dierckxsens C,Srivastava K,Reza M,et al.A distributed DC voltage control method for VSC MTDC systems[J].Electric Power System Research,2012,82(1):54-58. [14]Haileselassie T M,Uhlen K.Impact of DC line voltage droops on power flow of MTDC using droop control[J].IEEE Transactions on Power Systems,2012,27(3):1441-1449. [15]阎发友,汤广福,贺之渊,等.基于MMC的多端柔性直流输电系统改进下垂控制策略[J].中国电机工程学报,2014,34(3):397-404. Yan Fayou,Tang Guangfu,He Zhiyuan,et al.An improved droop control strategy for MMC-based VSC-MTDC systems[J].Proceedings of the CSEE,2014,34(3):397-404. [16]Chaudhuri N R,Chaudhuri B.Adaptive droop control for effective power sharing in multi-terminal DC (MTDC) grids[J].IEEE Transactions on Power Systems,2013,28(1):21-29. [17]郭春义,赵成勇,王晶.新型双馈入直流输电系统供电无源网络的运行特性研究[M].电工技术学报,2012,27(11):211-218. Guo Chunyi,Zhao Chengyong,Wang Jing.Operation characteristic research on novel double-infeed HVDC system supplying passive network[J].Transactions of China Electrotechnical Society,2012,27(11):211-218. [18]Abdel-Khalik A S,Massoud A M,Elserougi A A,et al.Optimum power transmission-based droop control design for Multi-terminal HVDC of offshore wind farms[J].IEEE Transactions on Power Systems,2013,28(3):3401-3409.