下垂控制对直流电网动态电压稳定性的影响分析
|
摘要
直流电网的协调控制策略包括主从控制、直流电压裕度控制及直流电压下垂控制等。下垂控制可以实现直流电网的多点直流电压控制,但下垂系数的大小会对系统直流侧电压的稳定性产生一定的影响。以基于模块化多电平换流器(Modular Multilevel Converter, MMC)的直流电网为研究对象,首先建立了下垂控制作用下MMC直流电压控制系统模型及其传递函数,并在此基础上,采用劳斯判据得到了能够保持系统直流电压稳定的下垂系数取值范围。然后,分别在时域和频域中分析了在不同取值区间内选取下垂系数对系统直流侧电压控制特性和稳定性的影响。最后,在PSCAD/EMTDC中建立了基于MMC的4端直流电网仿真模型,验证了理论分析的正确性,为工程应用时合理选择下垂系数提供了理论依据。
Coordinating control strategies of DC grids include master slave control, voltage margin control and voltage droop control, etc. Droop control could achieve distributed voltage control of DC grid, but the droop coefficients would influence the stability of the system. A Modular Multilevel Converters(MMCs) based DC grid is investigated. First, the mathematical model of the MMCs with droop control and its transfer functions are derived. Then, a reasonable value range of droop coefficients that would maintain the system stability is presented by the Routh criterion. The influences of selection of droop coefficients in different ranges on voltage stability are analyzed in time domain and frequency domain respectively. Finally, a four-terminal MMCs based DC grid model is established in PSCAD/EMTDC. The simulation results verify the correctness of the theoretical analysis, and the analysis method will provide a theoretical basis of droop coefficients selection for DC grid applications.
Coordinating control strategies of DC grids include master slave control, voltage margin control and voltage droop control, etc. Droop control could achieve distributed voltage control of DC grid, but the droop coefficients would influence the stability of the system. A Modular Multilevel Converters(MMCs) based DC grid is investigated. First, the mathematical model of the MMCs with droop control and its transfer functions are derived. Then, a reasonable value range of droop coefficients that would maintain the system stability is presented by the Routh criterion. The influences of selection of droop coefficients in different ranges on voltage stability are analyzed in time domain and frequency domain respectively. Finally, a four-terminal MMCs based DC grid model is established in PSCAD/EMTDC. The simulation results verify the correctness of the theoretical analysis, and the analysis method will provide a theoretical basis of droop coefficients selection for DC grid applications.
引文
[1]张丽英,叶廷路,辛耀中,等.大规模风电接入电网的相关问题及措施[J].中国电机工程学报,2010,30(25):1-9.ZHANG Liying,YE Tinglu,XIN Yaozhong,et al.Problems and measures of power grid accommodating large scale wind power[J].Proceedings of the CSEE,2010,30(25):1-9.
[2]温家良,吴锐,彭畅,等.直流电网在中国的应用前景分析[J].中国电机工程学报,2012,32(13):7-12.WEN Jialiang,WU Rui,PENG Chang,et al.Analysis of DC grid prospects in China[J].Proceedings of the CSEE,2012,32(13):7-12.
[3]汤广福,罗湘,魏晓光.多端直流输电与直流电网技术[J].中国电机工程学报,2013,33(10):8-17.TANG Guangfu,LUO Xiang,WEI Xiaoguang.Multiterminal HVDC and DC-grid technology[J].Proceedings of the CSEE,2013,33(10):8-17.
[4]TANG Guangfu,HE Zhiyuan,PANG Hui.R&D and application of voltage sourced converter based high voltage direct current engineering technology in China[J].Journal of Modern Power Systems and Clean Energy,2014,2(1):1-15.
[5]姚美齐,李乃湖.欧洲超级电网的发展及其解决方案[J].电网技术,2014,38(3):549-555.YAO Meiqi,LI Naihu.An introduction to European supergrid and its solutions[J].Power System Technology,2014,38(3):549-555.
[6]CIGRE B4-52 Working Group.HVDC grid feasibility study[R].Melbourne:International Council on Large Electric Systems,2011.
[7]洪莎莎,武迪,吕宏水,等.基于高阶系统模型的VSC-MTDC下垂控制策略研究[J].电力系统保护与控制,2017,45(22):125-131.HONG Shasha,WU Di,LüHongshui,et al.Droop control strategy research of VSC-MTDC based on high-order system model[J].Power System Protection and Control,2017,45(22):125-131.
[8]曹乐萌,赵巧娥,高金城,等.HVDC系统中MMC换流器控制策略研究[J].智慧电力,2017,45(10):31-36.CAO Lemeng,ZHAO Qiaoe,GAO Jincheng,et al.Research on control strategy for MMC converter in HVDC System[J].Smart Power,2017,45(10):31-36.
[9]黄强,陈亮,袁晓冬,等.多端直流配电系统工程仿真分析及示范应用[J].供用电,2018,35(6):24-32.HUANG Qiang,CHEN Liang,YUAN Xiaodong,et al.Multi-terminal DC distribution system engineering simulation analysis and demonstration application[J].Distribution&Utilization,2018,35(6):24-32.
[10]李国庆,孙银锋,吴学光.柔性直流输电稳定性分析及控制参数整定[J].电工技术学报,2017,32(6):231-239.LI Guoqing,SUN Yinfeng,WU Xueguang.VSC-HVDCstability analysis and control parameter setting[J].Transactions of China Electrotechnical society,2017,32(6):231-239.
[11]韩民晓,翟冬玲,唐晓骏.连接低惯量系统的柔性直流输电模型预测控制[J].电工技术学报,2017,32(22):198-206.HAN Minxiao,ZHAI Dongling,TANG Xiaojun.Model predictive control of voltage source converter-HVDCconnected to low inertia system[J].Transactions of China Electrotechnical Society,2017,32(22):198-206.
[12]张天,龚雁峰.特高压交直流电网输电技术及运行特性综述[J].智慧电力,2018,46(2):87-92.ZHANG Tian,GONG Yanfeng.Research on transmission technologies and operational performance of UHV AC/DCpower grid in China[J].Smart Power,2018,46(2):87-92.
[13]王柯,李继红,田杰,等.多端柔性直流故障快速恢复系统控制策略[J].供用电,2017,34(8):2-7.WANG Ke,LI Jihong,TIAN Jie,et al.Control strategy of quick recovery system with multi-terminals HVDCDC fault[J].Distribution&Utilization,2017,34(8):2-7.
[14]徐进,金逸,胡从川,等.适用于海上风电并网的多端柔性直流系统自适应下垂控制研究[J].电力系统保护与控制,2018,46(4):78-85.XU Jin,JIN Yi,HU Congchuan,et al.DC voltage adaptive droop control of multi-terminal VSC-HVDCsystem for offshore wind farms integration[J].Power System Protection and Control,2018,46(4):78-85.
[15]吴杰,王志新.多端柔性直流输电系统的改进下垂控制策略[J].电工技术学报,2017,32(20):241-250.WU Jie,WANG Zhixin.Improved droop control strategy for multi-terminal voltage source converter-HVDC[J].Transactions of China Electrotechnical society,2017,32(20):241-250.
[16]BEERTEN J,BELMANS R.Analysis of power sharing and voltage deviations in droop-controlled DC grids[J].IEEE Transactions on Power Systems,2013,28(3):4588-4597.
[17]ABDEL-KHALIK A,MASSOUD A,ELSEROUGI 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.
[18]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.
[19]韩民晓,熊凌飞,丁辉.利用电压斜率控制的VSC_MTDC稳定性分析[J].电网技术,2015,39(7):1808-1813.HAN Minxiao,XIONG Lingfei,DING Hui.Stability analysis of VSC-MTDC with voltage droop control[J].Power System Technology,2015,39(7):1808-1813.
[20]刘盼盼,荆龙,吴学智,等.一种MMC_MTDC系统新型协调控制策略[J].电网技术,2016,40(1):64-69.LIU Panpan,JING Long,WU Xuezhi,et al.A new coordinated control strategy for MMC-MTDC system and stability analysis[J].Power System Technology,2016,40(1):64-69.
[21]刘宁宁,曹炜,赵晋斌.直流微电网的一种增量式下垂控制方法[J].电力系统保护与控制,2018,46(8):24-30.LIU Ningning,CAO Wei,ZHAO Jinbin.An incremental droop control method for DC micro-grid[J].Power System Protection and Control,2018,46(8):24-30.
[22]TAO Fen,XIE Zhujun,CHENG Jie,et al.Fast valve power loss evaluation method for modular multi-level converter operating at high-frequency[J].Protection and Control of Modern Power Systems,2016,1(1):26-36.DOI:10.1186/s41601-016-0015-z.
[23]徐政,屠卿瑞,管敏渊,等.柔性直流输电系统[M].北京:机械工业出版社,2012:28-32.
[24]胡静.基于MMC的多端直流输电系统控制方法研究[D].北京:华北电力大学,2013:48-51.HU Jing.Research on control method for multi-terminal DC transmission system based on MMC[D].Beijing:North China Electric Power University,2013:48-51.
[25]赵岩,胡学浩,汤广福,等.模块化多电平变流器HVDC输电系统控制策略[J].中国电机工程学报,2011,31(25):35-42.ZHAO Yan,HU Xuehao,TANG Guangfu,et al.Control strategy of modular multilevel converters based HVDCtransmission[J].Proceedings of the CSEE,2011,31(25):35-42.
[26]王孝武,方敏,葛锁良.自动控制理论[M].北京:机械工业出版社,2009:75-82.
[27]赵岩.基于模块化多电平电压源型变流器的动态特性及其控制策略研究[D].北京:中国电力科学研究院,2010:36-38.ZHAO Yan.Research on dynamic characteristics and control strategies of modular multilevel converters[D].Beijing:China Electric Power Research Institute,2010:36-38.
[2]温家良,吴锐,彭畅,等.直流电网在中国的应用前景分析[J].中国电机工程学报,2012,32(13):7-12.WEN Jialiang,WU Rui,PENG Chang,et al.Analysis of DC grid prospects in China[J].Proceedings of the CSEE,2012,32(13):7-12.
[3]汤广福,罗湘,魏晓光.多端直流输电与直流电网技术[J].中国电机工程学报,2013,33(10):8-17.TANG Guangfu,LUO Xiang,WEI Xiaoguang.Multiterminal HVDC and DC-grid technology[J].Proceedings of the CSEE,2013,33(10):8-17.
[4]TANG Guangfu,HE Zhiyuan,PANG Hui.R&D and application of voltage sourced converter based high voltage direct current engineering technology in China[J].Journal of Modern Power Systems and Clean Energy,2014,2(1):1-15.
[5]姚美齐,李乃湖.欧洲超级电网的发展及其解决方案[J].电网技术,2014,38(3):549-555.YAO Meiqi,LI Naihu.An introduction to European supergrid and its solutions[J].Power System Technology,2014,38(3):549-555.
[6]CIGRE B4-52 Working Group.HVDC grid feasibility study[R].Melbourne:International Council on Large Electric Systems,2011.
[7]洪莎莎,武迪,吕宏水,等.基于高阶系统模型的VSC-MTDC下垂控制策略研究[J].电力系统保护与控制,2017,45(22):125-131.HONG Shasha,WU Di,LüHongshui,et al.Droop control strategy research of VSC-MTDC based on high-order system model[J].Power System Protection and Control,2017,45(22):125-131.
[8]曹乐萌,赵巧娥,高金城,等.HVDC系统中MMC换流器控制策略研究[J].智慧电力,2017,45(10):31-36.CAO Lemeng,ZHAO Qiaoe,GAO Jincheng,et al.Research on control strategy for MMC converter in HVDC System[J].Smart Power,2017,45(10):31-36.
[9]黄强,陈亮,袁晓冬,等.多端直流配电系统工程仿真分析及示范应用[J].供用电,2018,35(6):24-32.HUANG Qiang,CHEN Liang,YUAN Xiaodong,et al.Multi-terminal DC distribution system engineering simulation analysis and demonstration application[J].Distribution&Utilization,2018,35(6):24-32.
[10]李国庆,孙银锋,吴学光.柔性直流输电稳定性分析及控制参数整定[J].电工技术学报,2017,32(6):231-239.LI Guoqing,SUN Yinfeng,WU Xueguang.VSC-HVDCstability analysis and control parameter setting[J].Transactions of China Electrotechnical society,2017,32(6):231-239.
[11]韩民晓,翟冬玲,唐晓骏.连接低惯量系统的柔性直流输电模型预测控制[J].电工技术学报,2017,32(22):198-206.HAN Minxiao,ZHAI Dongling,TANG Xiaojun.Model predictive control of voltage source converter-HVDCconnected to low inertia system[J].Transactions of China Electrotechnical Society,2017,32(22):198-206.
[12]张天,龚雁峰.特高压交直流电网输电技术及运行特性综述[J].智慧电力,2018,46(2):87-92.ZHANG Tian,GONG Yanfeng.Research on transmission technologies and operational performance of UHV AC/DCpower grid in China[J].Smart Power,2018,46(2):87-92.
[13]王柯,李继红,田杰,等.多端柔性直流故障快速恢复系统控制策略[J].供用电,2017,34(8):2-7.WANG Ke,LI Jihong,TIAN Jie,et al.Control strategy of quick recovery system with multi-terminals HVDCDC fault[J].Distribution&Utilization,2017,34(8):2-7.
[14]徐进,金逸,胡从川,等.适用于海上风电并网的多端柔性直流系统自适应下垂控制研究[J].电力系统保护与控制,2018,46(4):78-85.XU Jin,JIN Yi,HU Congchuan,et al.DC voltage adaptive droop control of multi-terminal VSC-HVDCsystem for offshore wind farms integration[J].Power System Protection and Control,2018,46(4):78-85.
[15]吴杰,王志新.多端柔性直流输电系统的改进下垂控制策略[J].电工技术学报,2017,32(20):241-250.WU Jie,WANG Zhixin.Improved droop control strategy for multi-terminal voltage source converter-HVDC[J].Transactions of China Electrotechnical society,2017,32(20):241-250.
[16]BEERTEN J,BELMANS R.Analysis of power sharing and voltage deviations in droop-controlled DC grids[J].IEEE Transactions on Power Systems,2013,28(3):4588-4597.
[17]ABDEL-KHALIK A,MASSOUD A,ELSEROUGI 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.
[18]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.
[19]韩民晓,熊凌飞,丁辉.利用电压斜率控制的VSC_MTDC稳定性分析[J].电网技术,2015,39(7):1808-1813.HAN Minxiao,XIONG Lingfei,DING Hui.Stability analysis of VSC-MTDC with voltage droop control[J].Power System Technology,2015,39(7):1808-1813.
[20]刘盼盼,荆龙,吴学智,等.一种MMC_MTDC系统新型协调控制策略[J].电网技术,2016,40(1):64-69.LIU Panpan,JING Long,WU Xuezhi,et al.A new coordinated control strategy for MMC-MTDC system and stability analysis[J].Power System Technology,2016,40(1):64-69.
[21]刘宁宁,曹炜,赵晋斌.直流微电网的一种增量式下垂控制方法[J].电力系统保护与控制,2018,46(8):24-30.LIU Ningning,CAO Wei,ZHAO Jinbin.An incremental droop control method for DC micro-grid[J].Power System Protection and Control,2018,46(8):24-30.
[22]TAO Fen,XIE Zhujun,CHENG Jie,et al.Fast valve power loss evaluation method for modular multi-level converter operating at high-frequency[J].Protection and Control of Modern Power Systems,2016,1(1):26-36.DOI:10.1186/s41601-016-0015-z.
[23]徐政,屠卿瑞,管敏渊,等.柔性直流输电系统[M].北京:机械工业出版社,2012:28-32.
[24]胡静.基于MMC的多端直流输电系统控制方法研究[D].北京:华北电力大学,2013:48-51.HU Jing.Research on control method for multi-terminal DC transmission system based on MMC[D].Beijing:North China Electric Power University,2013:48-51.
[25]赵岩,胡学浩,汤广福,等.模块化多电平变流器HVDC输电系统控制策略[J].中国电机工程学报,2011,31(25):35-42.ZHAO Yan,HU Xuehao,TANG Guangfu,et al.Control strategy of modular multilevel converters based HVDCtransmission[J].Proceedings of the CSEE,2011,31(25):35-42.
[26]王孝武,方敏,葛锁良.自动控制理论[M].北京:机械工业出版社,2009:75-82.
[27]赵岩.基于模块化多电平电压源型变流器的动态特性及其控制策略研究[D].北京:中国电力科学研究院,2010:36-38.ZHAO Yan.Research on dynamic characteristics and control strategies of modular multilevel converters[D].Beijing:China Electric Power Research Institute,2010:36-38.