弱电网下无功控制对并网变流器稳定性影响分析
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摘要
可再生能源经变流器接入弱电网时,变流器向电网输出无功功率有利于提高并网点的电压质量,但是无功控制的动态特性对变流器系统的稳定性有重要的影响。为分析此影响,文中建立了采用定无功功率控制策略下变流器的阻抗模型,通过分析无功控制外环动态改变所引起的各元素阻抗特性变化,判断无功控制外环动态对系统稳定性的影响,并采用广义奈奎斯特判据验证上述分析结论。其次,采用特征根轨迹法,分析了无功控制外环比例参数及电网强度的变化对系统稳定性的影响,结果表明弱电网下无功控制外环可能引发中高频振荡问题。最后,基于RT-LAB进行在环仿真验证理论分析结果。
When the renewable energy is connected to the weak grid through the converter,the output reactive power from converter to grid is beneficial to improve the voltage quality of connection point.But the dynamic characteristics of reactive power control have huge impacts on the stability of the converter system.To explore the impacts,the impedance model of converters with the fixed reactive power control strategy is proposed.By analyzing the impedance characteristics of each element changed by the dynamic variation of outer reactive power control loop,the influence of the dynamic outer reactive power control loop on system stability is judged,and the generalized Nyquist criterion is used to verify the above analysis conclusion.Moreover,the eigenvalue analysis method is used to explore the influences of the proportional parameter of outer reactive power control loop and the strength of the grid on system stability.The results reveal that the outer reactive power control loop may cause medium/high frequency oscillations when the converters are connected to weak grids.Finally,the hardware-in-the-loop(HIL)simulation is conducted to validate the theoretical analysis results based on RT-LAB.
When the renewable energy is connected to the weak grid through the converter,the output reactive power from converter to grid is beneficial to improve the voltage quality of connection point.But the dynamic characteristics of reactive power control have huge impacts on the stability of the converter system.To explore the impacts,the impedance model of converters with the fixed reactive power control strategy is proposed.By analyzing the impedance characteristics of each element changed by the dynamic variation of outer reactive power control loop,the influence of the dynamic outer reactive power control loop on system stability is judged,and the generalized Nyquist criterion is used to verify the above analysis conclusion.Moreover,the eigenvalue analysis method is used to explore the influences of the proportional parameter of outer reactive power control loop and the strength of the grid on system stability.The results reveal that the outer reactive power control loop may cause medium/high frequency oscillations when the converters are connected to weak grids.Finally,the hardware-in-the-loop(HIL)simulation is conducted to validate the theoretical analysis results based on RT-LAB.
引文
[1]康重庆,姚良忠.高比例可再生能源电力系统的关键科学问题与理论研究框架[J].电力系统自动化,2017,41(9):1-11.DOI:10.7500/APES20170120004.KANG Chongqing,YAO Liangzhong.Key scientific issues and theoretical research framework for power systems with high proportion of renewable energy[J].Automation of Electric Power Systems,2017,41(9):1-11.DOI:10.7500/APES20170120004.
[2]王旭斌,杜文娟,王海风.弱连接条件下并网VSC系统稳定性分析研究综述[J].中国电机工程学报,2018,38(6):1593-1604.WANG Xubin,DU Wenjuan,WANG Haifeng.Stability analysis of grid-tied VSC systems under weak connection conditions[J].Proceedings of the CSEE,2018,38(6):1593-1604.
[3]谢小荣,刘华坤,贺静波,等.新能源发电并网系统的小信号阻抗/导纳网络建模方法[J].电力系统自动化,2017,41(12):26-32.DOI:10.7500/AEPS20170125005.XIE Xiaorong,LIU Huakun,HE Jingbo,et al.Small-signal impedance/admittance network modeling for grid-connected renewable energy generation systems[J].Automation of Electric Power Systems,2017,41(12):26-32.DOI:10.7500/AEPS20170125005.
[4]袁辉,辛焕海,王康,等.弱电网下远端严重电压跌落时逆变器并网失稳机理分析[J].电力系统自动化,2018,42(22):38-43.DOI:10.7500/AEPS201709100001.YUAN Hui,XIN Huanhai,WANG Kang,et al.Instability mechanism analysis of inverters connected to weak grid during severe voltage sag on remote grid side[J].Automation of Electric Power Systems,2018,42(22):38-43.DOI:10.7500/AEPS201709100001.
[5]陈宁,何维国,钱敏慧,等.风电场无功电压控制系统设计和应用[J].电力系统自动化,2011,35(23):32-36.CHEN Ning,HE Weiguo,QIAN Minhui,et al.Design and application of reactive power control system for wind farm[J].Automation of Electric Power Systems,2011,35(23):32-36.
[6]朱凌志,陈宁,王伟.兼顾接入地区无功需求的风电场无功控制策略[J].电力系统自动化,2009,33(5):80-85.ZHU Lingzhi,CHEN Ning,WANG Wei.Wind farm reactive power control strategy considering local networks demand[J].Automation of Electric Power Systems,2009,33(5):80-85.
[7]ZHOU J Z,DING Hui,FAN Shengtao,et al.Impact of shortcircuit ratio and phase-locked-loop parameters on the smallsignal behavior of a VSC-HVDC converter[J].IEEETransactions on Power Delivery,2014,29(5):2287-2296.
[8]张学广,付志超,陈文佳,等.弱电网下考虑锁相环影响的并网逆变器改进控制方法[J].电力系统自动化,2018,42(7):139-145.DOI:10.7500/AEPS20170623002.ZHANG Xueguang,FU Zhichao,CHEN Wenjia,et al.An improved control method for grid-connected inverters considering impact of phase-locked loop under weak grid condition[J].Automation of Electric Power Systems,2018,42(7):139-145.DOI:10.7500/AEPS20170623002.
[9]贾祺,严干贵,李泳霖,等.多光伏发电单元并联接入弱交流系统的稳定性分析[J].电力系统自动化,2018,42(3):14-20.DOI:10.7500/AEPS20170610002.JIA Qi,YAN Gangui,LI Yonglin,et al.Stability analysis of multiple paralleled photovoltaic power generation units connected to weak AC system[J].Automation of Electric Power Systems,2018,42(3):14-20.DOI:10.7500/AEPS20170610002.
[10]ZHAO Mingquan,YUAN Xiaoming,HU Jiabing,et al.Voltage dynamics of current control time-scale in a VSC-connected weak grid[J].IEEE Transactions on Power Systems,2016,31(4):2925-2937.
[11]HUANG Yunhui,YUAN Xiaoming,HU Jiabing.Effect of reactive power control on stability of DC-link voltage control in VSC connected to weak grid[C]//IEEE PES General Meeting Conference&Exposition,July 27-31,2014,National Harbor,USA.
[12]HUANG Yunhui,YUAN Xiaoming,HU Jiabing,et al.DC-bus voltage control stability affected by AC-bus voltage control in VSCs connected to weak AC grids[J].IEEE Journal of Emerging and Selected Topics in Power Electronics,2016,4(2):445-458.
[13]袁艺嘉,赵成勇,苑宾,等.弱交流电网条件下VSC无功类控制分析与优化[J].电网技术,2016,40(3):696-703.YUAN Yijia,ZHAO Chengyong,YUAN Bin,et al.Analysis and optimization of reactive power controllers of voltage source converters in weak AC grid[J].Power System Technology,2016,40(3):696-703.
[14]KHAZAEI J,IDOWU P,ASRARI A,et al.Review of HVDC control in weak AC grids[J].Electric Power Systems Research,2018,162:194-206.
[15]CESPEDES M,SUN Jian.Impedance modeling and analysis of grid-connected voltage-source converters[J].IEEETransactions on Power Electronics,2014,29(3):1254-1261.
[16]辛焕海,李子恒,董炜,等.三相变流器并网系统的广义阻抗及稳定判据[J].中国电机工程学报,2017,37(5):1277-1293.XIN Huanhai,LI Ziheng,DONG Wei,et al.Generalizedimpedance and stability criterion for grid-connected converters[J].Proceedings of the CSEE,2017,37(5):1277-1293.
[17]WEN B,BOROYEVICH D,BURGOS R,et al.Small-signal stability analysis of three-phase AC systems in the presence of constant power loads based on measured dqframe impedances[J].IEEE Transactions on Power Electronics,2015,30(10):5952-5963.
[18]WEN Bo,DONG Dong,BOROYEVICH D,et al.Impedancebased analysis of grid-synchronization stability for three-phase paralleled converters[J].IEEE Transactions on Power Electronics,2016,31(1):26-38.
[19]WEN Bo,BOROYEVICH D,BURGOS R,et al.Analysis of d-q small-signal impedance of grid-tied inverters[J].IEEETransactions on Power Electronics,2016,31(1):675-687.
[20]LU Dapeng,WANG Xiongfei,BLAABJERG F.Impedancebased analysis of DC-link voltage dynamics in voltage-source converters[J].IEEE Transactions on Power Electronics,2019,34(4):3973-3985.
[21]王萍,王尉,贝太周,等.数字控制对并网逆变器的影响及抑制方法[J].天津大学学报:自然科学与工程技术版,2016,49(5):472-479.WANG Ping,WANG Wei,BEI Taizhou,et al.Effects of digital control on grid-connected inverter and its suppression method[J].Journal of Tianjin University(Science and Technology),2016,49(5):472-479.
[22]高黛陵,吴麒.多变量频率域控制理论[M].北京:清华大学出版社,1998.GAO Dailing,WU Qi.Theory of multivariable control in frequency domain[M].Beijing:Tsinghua University Press,1998.
[2]王旭斌,杜文娟,王海风.弱连接条件下并网VSC系统稳定性分析研究综述[J].中国电机工程学报,2018,38(6):1593-1604.WANG Xubin,DU Wenjuan,WANG Haifeng.Stability analysis of grid-tied VSC systems under weak connection conditions[J].Proceedings of the CSEE,2018,38(6):1593-1604.
[3]谢小荣,刘华坤,贺静波,等.新能源发电并网系统的小信号阻抗/导纳网络建模方法[J].电力系统自动化,2017,41(12):26-32.DOI:10.7500/AEPS20170125005.XIE Xiaorong,LIU Huakun,HE Jingbo,et al.Small-signal impedance/admittance network modeling for grid-connected renewable energy generation systems[J].Automation of Electric Power Systems,2017,41(12):26-32.DOI:10.7500/AEPS20170125005.
[4]袁辉,辛焕海,王康,等.弱电网下远端严重电压跌落时逆变器并网失稳机理分析[J].电力系统自动化,2018,42(22):38-43.DOI:10.7500/AEPS201709100001.YUAN Hui,XIN Huanhai,WANG Kang,et al.Instability mechanism analysis of inverters connected to weak grid during severe voltage sag on remote grid side[J].Automation of Electric Power Systems,2018,42(22):38-43.DOI:10.7500/AEPS201709100001.
[5]陈宁,何维国,钱敏慧,等.风电场无功电压控制系统设计和应用[J].电力系统自动化,2011,35(23):32-36.CHEN Ning,HE Weiguo,QIAN Minhui,et al.Design and application of reactive power control system for wind farm[J].Automation of Electric Power Systems,2011,35(23):32-36.
[6]朱凌志,陈宁,王伟.兼顾接入地区无功需求的风电场无功控制策略[J].电力系统自动化,2009,33(5):80-85.ZHU Lingzhi,CHEN Ning,WANG Wei.Wind farm reactive power control strategy considering local networks demand[J].Automation of Electric Power Systems,2009,33(5):80-85.
[7]ZHOU J Z,DING Hui,FAN Shengtao,et al.Impact of shortcircuit ratio and phase-locked-loop parameters on the smallsignal behavior of a VSC-HVDC converter[J].IEEETransactions on Power Delivery,2014,29(5):2287-2296.
[8]张学广,付志超,陈文佳,等.弱电网下考虑锁相环影响的并网逆变器改进控制方法[J].电力系统自动化,2018,42(7):139-145.DOI:10.7500/AEPS20170623002.ZHANG Xueguang,FU Zhichao,CHEN Wenjia,et al.An improved control method for grid-connected inverters considering impact of phase-locked loop under weak grid condition[J].Automation of Electric Power Systems,2018,42(7):139-145.DOI:10.7500/AEPS20170623002.
[9]贾祺,严干贵,李泳霖,等.多光伏发电单元并联接入弱交流系统的稳定性分析[J].电力系统自动化,2018,42(3):14-20.DOI:10.7500/AEPS20170610002.JIA Qi,YAN Gangui,LI Yonglin,et al.Stability analysis of multiple paralleled photovoltaic power generation units connected to weak AC system[J].Automation of Electric Power Systems,2018,42(3):14-20.DOI:10.7500/AEPS20170610002.
[10]ZHAO Mingquan,YUAN Xiaoming,HU Jiabing,et al.Voltage dynamics of current control time-scale in a VSC-connected weak grid[J].IEEE Transactions on Power Systems,2016,31(4):2925-2937.
[11]HUANG Yunhui,YUAN Xiaoming,HU Jiabing.Effect of reactive power control on stability of DC-link voltage control in VSC connected to weak grid[C]//IEEE PES General Meeting Conference&Exposition,July 27-31,2014,National Harbor,USA.
[12]HUANG Yunhui,YUAN Xiaoming,HU Jiabing,et al.DC-bus voltage control stability affected by AC-bus voltage control in VSCs connected to weak AC grids[J].IEEE Journal of Emerging and Selected Topics in Power Electronics,2016,4(2):445-458.
[13]袁艺嘉,赵成勇,苑宾,等.弱交流电网条件下VSC无功类控制分析与优化[J].电网技术,2016,40(3):696-703.YUAN Yijia,ZHAO Chengyong,YUAN Bin,et al.Analysis and optimization of reactive power controllers of voltage source converters in weak AC grid[J].Power System Technology,2016,40(3):696-703.
[14]KHAZAEI J,IDOWU P,ASRARI A,et al.Review of HVDC control in weak AC grids[J].Electric Power Systems Research,2018,162:194-206.
[15]CESPEDES M,SUN Jian.Impedance modeling and analysis of grid-connected voltage-source converters[J].IEEETransactions on Power Electronics,2014,29(3):1254-1261.
[16]辛焕海,李子恒,董炜,等.三相变流器并网系统的广义阻抗及稳定判据[J].中国电机工程学报,2017,37(5):1277-1293.XIN Huanhai,LI Ziheng,DONG Wei,et al.Generalizedimpedance and stability criterion for grid-connected converters[J].Proceedings of the CSEE,2017,37(5):1277-1293.
[17]WEN B,BOROYEVICH D,BURGOS R,et al.Small-signal stability analysis of three-phase AC systems in the presence of constant power loads based on measured dqframe impedances[J].IEEE Transactions on Power Electronics,2015,30(10):5952-5963.
[18]WEN Bo,DONG Dong,BOROYEVICH D,et al.Impedancebased analysis of grid-synchronization stability for three-phase paralleled converters[J].IEEE Transactions on Power Electronics,2016,31(1):26-38.
[19]WEN Bo,BOROYEVICH D,BURGOS R,et al.Analysis of d-q small-signal impedance of grid-tied inverters[J].IEEETransactions on Power Electronics,2016,31(1):675-687.
[20]LU Dapeng,WANG Xiongfei,BLAABJERG F.Impedancebased analysis of DC-link voltage dynamics in voltage-source converters[J].IEEE Transactions on Power Electronics,2019,34(4):3973-3985.
[21]王萍,王尉,贝太周,等.数字控制对并网逆变器的影响及抑制方法[J].天津大学学报:自然科学与工程技术版,2016,49(5):472-479.WANG Ping,WANG Wei,BEI Taizhou,et al.Effects of digital control on grid-connected inverter and its suppression method[J].Journal of Tianjin University(Science and Technology),2016,49(5):472-479.
[22]高黛陵,吴麒.多变量频率域控制理论[M].北京:清华大学出版社,1998.GAO Dailing,WU Qi.Theory of multivariable control in frequency domain[M].Beijing:Tsinghua University Press,1998.
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