摘要
不平衡电网电压条件下,双馈感应发电机定、转子电流会出现不平衡现象,影响机组安全稳定运行,且系统输出功率产生2倍频波动。为显著提高双馈风力发电系统的运行性能和输出品质,首先通过分析双馈风力发电系统采用串联网侧变换器的运行机理,提出以维持定子三相电压平衡为目标的串联网侧变换器控制策略,并保证风机定、转子三相电流平衡;在此基础上,通过分析并联网侧变换器在电网电压不平衡条件下的数学模型,推导并建立并联网侧变换器在不平衡电网电压条件下2倍频功率的控制方程;计及串联网侧变换器产生的功率2倍频分量,提出基于降阶谐振功率补偿器的并联网侧变换器控制策略,达到同时抑制系统输出有功、无功功率2倍频波动的目的。最后基于PSCAD/EMTDC平台搭建双馈风力发电系统仿真模型,验证所提策略的正确性和有效性。
Under unbalanced grid voltage, the stator and rotor currents of a doubly fed induction generator(DFIG) are unbalanced, which influences the safe and stable operation of the machine, and double frequency ripples will appear in the output power of the doubly fed wind power generation system. In order to improve the operational performance and output quality of the system significantly, the operation mechanism of the doubly fed wind power generation system with a series grid side converter(SGSC) is analyzed in this paper, and the control strategy for the SGSC aiming at maintaining the stator voltage balance is proposed, which ensures the balance of stator and rotor three-phase currents. On the basis of the system with a SGSC, the mathematical model of the parallel grid side converters(PGSC) under unbalanced grid voltage is analyzed, and the double frequency power control equation is established. Combined with the double frequency ripples generated by the SGSC, a control strategy based on a reduced-order resonant power compensator for the PGSC is proposed, the goal of simultaneously suppressing the double frequency ripples of the output active and reactive power of the system is achieved. The proposed strategy which is proved to be correct and effective by the simulations of a doubly fed wind power generation system model in PSCAD/EMTDC.
引文
[1]贺益康,周鹏.变速恒频双馈异步风力发电系统低电压穿越技术综述[J].电工技术学报,2009,24(9):140-146.He Yikang,Zhou Peng.Overview of the low voltage ride-through technology for variable speed constant frequency doubly fed wind power generation systems[J].Transactions of China Electrotechnical Society,2009,24(9):140-146.
[2]马少康,耿华,马进,等.双馈型风电场详细模型建模方法[J].电工技术学报,2017,32(增刊1):1-10.Ma Shaokang,Geng Hua,Ma Jin,et al.An approach to establish detailed model of DFIG based wind farm[J].Transactions of China Electrotechnical Society 2017,32(S1):1-10.
[3]Cardenas R,Pena R,Alepuz S,et al.Overview of control systems for the operation of DFIGs in wind energy applications[J].IEEE Transactions on Industrial Electronics,2013,60(7):2776-2798.
[4]刘其辉,贺益康,赵仁德.交流励磁变速恒频风力发电系统的运行与控制[J].电工技术学报,2008,23(1):129-136.Liu Qihui,He Yikang,Zhao Rende.Operation and control of AC-exited variable-speed constantfrequency wind power generation system[J].Transactions of China Electrotechnical Society,2008,23(1):129-136.
[5]邱瑞昌,姜学东,闫耀民,等.转子感应电势定向的双馈电机风力发电系统研究[J].电工技术学报,2004,19(4):40-44.Qiu Ruichang,Jiang Xuedong,Yan Yaomin,et al.Research on rotor EMF-oriented doubly-fed wind power generation system[J].Transactions of China Electrotechnical Society,2004,19(4):40-44.
[6]马祎炜,俞俊杰,吴国祥,等.双馈风力发电系统最大功率点跟踪控制策略[J].电工技术学报,2009,24(4):202-208.Ma Yiwei,Yu Junjie,Wu Guoxiang,et al.MPPT control strategy for doubly-fed wind power generation[J].Transactions of China Electrotechnical Society,2009,24(4):202-208.
[7]Xu L.Coordinated control of DFIG's rotor and grid side converters during network unbalance[J].IEEE Transactions on Power Electronics,2008,23(3):1041-1049.
[8]胡家兵,贺益康,王宏胜.不平衡电网电压下双馈感应发电机转子侧变换器的比例-谐振电流控制策略[J].中国电机工程学报,2010,30(6):48-56.Hu Jiabing,He Yikang,Wang Hongsheng.Proportional-resonant current control scheme for rotor-side converter of doubly-fed induction generators under unbalanced network voltage conditions[J].Proceedings of the CSEE,2010,30(6):48-56.
[9]胡家兵,贺益康,王宏胜.不平衡电网电压下双馈感应发电机网侧和转子侧变换器的协同控制[J].中国电机工程学报,2010,30(9):97-104.Hu Jiabing,He Yikang,Wang Hongsheng.Coordinated control of grid and rotor-side converters of doubly fed induction generator under unbalanced network voltage conditions[J].Proceedings of the CSEE,2010,30(9):97-104.
[10]Hu J,He Y,Xu L,et al.Improved control of DFIG systems during network unbalance using PI-R current regulators[J].IEEE Transactions on Industrial Electronics,2009,56(2):439-451.
[11]王建良,张奕黄,程鹏,等.不平衡电网下基于降阶谐振器的双馈风电系统网侧变换器辅助控制策略[J].电工技术学报,2015,30(4):35-43.Wang Jianliang,Zhang Yihuang,Cheng Peng,et al.Auxiliary control strategy of DFIG’s GSC during network unbalance based on reduced-order resonant controller[J].Transactions of China Electrotechnical Society,2015,30(4):35-43.
[12]张迪,魏艳君,杨宗丰,等.不平衡电网电压下基于滑模变结构控制的双馈风电系统转子侧变流器控制策略[J].电工技术学报,2015,30(10):121-131.Zhang Di,Wei Yanjun,Yang Zongfeng,et al.Slidingmode control for rotor-side converters of DFIG-based wind-power generation system under unbalanced grid voltage conditions[J].Transactions of China Electrotechnical Society,2015,31(10):121-131.
[13]胡胜,林新春,康勇,等.一种双馈风力发电机在电网电压不平衡条件下的改进控制策略[J].电工技术学报,2011,26(7):21-29.Hu Sheng,Lin Xinchun,Kang Yong,et al.An improved control strategy of doubly-fed induction generator under grid voltage unbalance[J].Transactions of China Electrotechnical Society,2011,26(7):21-29.
[14]姚骏,郭利莎,陈知前,等.电网电压不平衡下双馈型风电场可控运行区域及其控制策略[J].电工技术学报,2016,31(20):181-191.Yao Jun,Guo Lisha,Chen Zhiqian,et al.Control strategy of doubly-fed type based wind farm and its controllable operation area under unbalanced grid voltage condition[J].Transactions of China Electrotechnical Society,2016,31(20):181-191.
[15]姚骏,廖勇,李辉,等.电网电压不平衡下采用串联网侧变换器的双馈感应风电系统改进控制[J].中国电机工程学报,2012,32(6):121-130.Yao Jun,Liao Yong,Li hui,et al.Improved control of a doubly fed induction generator wind turbines with a series grid-side converter under unbalanced grid voltage conditions[J].Proceedings of the CSEE,2012,32(6):121-130.
[16]Yao J,Li H,Chen Z,et al.Enhanced control of a DFIG-based wind-power generation system with series grid-side converter under unbalanced grid voltage conditions[J].IEEE Transactions on Power Electronics,2012,28(7):3167-3181.
[17]王萌,夏长亮,宋战锋,等.不平衡电网电压条件下PWM整流器功率谐振补偿控制策略[J].中国电机工程学报,2012,32(21):46-53.Wang Meng,Xia Changliang,Song Zhanfeng,et al.A power resonance compensation control strategy for PWM rectifiers under unbalanced grid voltage conditions[J].Proceedings of the CSEE,2012,32(21):46-53.
[18]赵新,金新民,周飞,等.基于比例积分-降阶谐振调节器的并网逆变器不平衡控制[J].中国电机工程学报,2013,33(19):84-92.Zhao Xin,Jin Xinmin,Zhou Fei,et al.Unbalanced control of grid-connected inverters based on proportion integra-land reduced order resonant controllers[J].Proceedings of the CSEE,2013,33(19):84-92.
[19]王成山.微电网分析与仿真理论[M].北京:科学出版社,2013.
[20]刘子文,苗世洪,范志华,等.不平衡电网电压下柔性直流输电系统功率滑模补偿策略[J].电工技术学报,2018,33(14):3296-3305.Liu Ziwen,Miao Shihong,Fan Zhihua,et al.Power sliding mode compensation strategy of VSC-HVDC under unbalanced grid voltage[J].Transactions of China Electrotechnical Society,2018,33(14):3296-3305.
[21]蒋连钿,张明,庄革,等.三相PWM整流器中基于虚拟无功的锁相环[J].电工技术学报,2013,28(8):212-217.Jiang Liandian,Zhang Ming,Zhuang Ge,et al.A phase-locked loop method for three-phase PWM rectifier based on virtual reactive power[J].Transactions of China Electrotechnical Society,2013,28(8):212-217.
[22]陈鉴庆,邹旭东,梁宗泽,等.基于反向电流跟踪的双馈风机低电压穿越控制策略[J].电工技术学报,2016,31(2):221-229.Chen Jianqing,Zou Xudong,Liang Zongze,et al.An improved control strategy of doubly-fed wind turbine under voltage dips based on reverse current tracking[J].Transactions of China Electrotechnical Society,2016,31(2):221-229.
[23]孟岩峰,胡书举,李旭,等.应用于动模试验系统的风电模拟技术研究[J].电工技术学报,2016,31(3):130-137.Meng Yanfeng,Hu Shuju,Li Xu,et al.Research on wind power simulation technology applied to power system dynamic simulation test system[J].Transactions of China Electrotechnical Society,2016,31(3):130-137.
[24]Song Peng,Zhang Yangfan,Bai Kai,et al.High voltage ride-through control method for DFIG-based wind turbines based on resonant controller[C]//2016IEEE International Conference on Power and Renewable Energy(ICPRE),Shanghai,China,2017:67-71.