Frequency Regulation of the Wind/Photovoltaic/Diesel Microgrid Based on DFIG Cooperative Strategy with Variable Coefficients BetweenVirtual Inertia and Over-speed Control
Zhao Jingjing,Lv Xue,Fu Yang,Hu Xiaoguang
Shanghai University of Electric Power Shanghai 200090 China
Abstract：To improve the frequency stability of the isolated islanding wind/photovoltaic/diesel microgrid,in this paper,the doubly fed induction generator(DFIG) and the diesel turbine are both utilized as the frequency regulation sources.Via coordinating virtual inertia control,rotor speed control,and automatic pitch control strategy,DFIG can cooperate with diesel turbine to restrain the frequency fluctuation caused by the change of the wind speed and the load.When operating at the below-rated wind speed,DFIG adoptsbothvirtual inertia control and over-speed control strategy.On the other hand,when at above-rated wind speed,DFIG utilizes virtual inertia control and automatic pitch control.Therefore,the output power drop during the recovery period of the rotor speed with virtual inertia control can be avoided.Moreover,this combined control strategy can provide permanent power support for the microgrid.In order to guarantee the efficiency of this strategy in a time-varying wind speed,an inertia coefficient curve and a droop control gain curve areplotted by analyzing parameter settings under different wind speeds,and as a result,the variable coefficient control is realized.This paper established the microgrid control model includes the diesel generator,photovoltaic power generator and DFIG using the software DIgSILENT PowerFactory.The simulation results show that this control strategy is valid.
赵晶晶,吕雪,符杨,胡晓光. 基于可变系数的双馈风机虚拟惯量与超速控制协调的风光柴微电网频率调节技术[J]. 电工技术学报, 2015, 30(5): 59-68.
Zhao Jingjing,Lv Xue,Fu Yang,Hu Xiaoguang. Frequency Regulation of the Wind/Photovoltaic/Diesel Microgrid Based on DFIG Cooperative Strategy with Variable Coefficients BetweenVirtual Inertia and Over-speed Control. Transactions of China Electrotechnical Society, 2015, 30(5): 59-68.
[1] 沈臣,顾伟,吴志.孤岛模式下的微电网低频减载策略分析[J].电力系统自动化,2011,35(9):47-52. Shen Chen,Gu Wei,Wu Zhi.An underfrequency load shedding strategy for islanded microgrid[J].Automation of Electric Power Systems,2011,35(9):47-52. [2] 丁明,杨向真,苏建徽.基于虚拟同步发电机思想的微电网逆变电源控制策略[J].电力系统自动化,2009,33(8):89-93. Ding Ming,Yang Xiangzhen,Su Jianhui.Control strategies of inverters based on virtual synchronous generator in a microgrid[J].Automation of Electric Power Systems,2009,33(8):89-93. [3] 杜威,姜齐荣,陈蛟瑞.微电网电源的虚拟惯性频率控制策略[J].电力系统自动化,2011,35(23):26-31. Du Wei,Jiang Qirong,Chen Jiaorui.Frequency control strategy of distributed generations based on virtual inertia in a microgrid[J].Automation of Electric Power Systems,2011,35(23):26-31. [4] Morren J,de Haan S W H,Ferreira J A.Contribution of DG units to primary frequency control[C].IEEE Future Power Systems International Conference,Amsterdam,2005:1-6. [5] Ekanayake J,Jenkins N.Comparison of the response of doubly fed and fixed-speed induction generator wind turbines to changes in network frequency[J].IEEE Transactions on Energy Conversion,2004,19(4):800-802. [6] Ramtharan G,Ekanayake J B,Jenkins N.Frequency supportfromdoubly fed induction generatorwind turbines[J].IET Renewable Power Generation,2007,1(1):3-9. [7] Mustafa K,Jovica V.Dynamic contribution of doubly-based wind plants to system frequency disturbances[J].IEEE Transactions on Power Systems,2009,24(22):859-867. [8] Almeida R G,Castronuovo E D,Pecas Lopes J A.Optimum generation control in wind parks when carrying out system operator requests[J].IEEE Transactions on Power Systems,2006,21(2):718-725. [9] Chang-Chien Le-Ren,Hung Chihmin,Yin Yao-ching.Dynamic reserve allocation for system contingency by DFIG wind farms[J].IEEE Transactions on Power Systems,2008,23(2):729-736. [10]张昭遂,孙元章,李国杰,等.超速与变桨协调的双馈风电机组频率控制[J].电力系统自动化,2011,35(17):20-25. Zhang Zhaosui,Sun Yuanzhang,Li Guojie,et al.Frequency regulation by doubly fed induction generator wind turbines based on coordinated overspeed control and pitch control[J].Automation of Electric Power Systems,2011,35(17):20-25. [11]杨永恒,周克亮.光伏电池建模及MPPT控制策略[J].电工技术学报,2011,26(s1):229-234. Yang Yongheng,Zhou Keliang.Photovoltaic cell modeling and MPPT control strategies[J].Transactions of China Electrotechnical Society,2011,26(s1):229-234. [12]蔡国伟,孔令国,潘超,等.风光储联合发电系统的建模及并网控制策略[J].电工技术学报,2013,28(9):196-204. Cai Guowei,Kong Lingguo,Pan Chao,et al.System modeling of wind-PV-ES hybrid power system and its control strategy for grid-connected[J].Transactions of China Electrotechnical Society,2013,28(9):196-204. [13]Wang Ye,Delille G,Bayem H.High wind penetration in isolated power systems—assessment of wind inertial and primary frequency reponese[J].IEEE Transactions on Power Systems,2013,38(3):2412-2420. [14]Knudsen H,Nielsen J N.Wind power in power systems-introduction to the modeling of wind turbines[M].United Kingdom:Wiley,2005,525-585. [15]刘巨,姚伟,文劲宇,等.大规模风电参与系统频率调整的技术展望[J].电网技术,2014,38(3):638-646. Liu Ju,Yao Wei,Wen Jinyu,et al.Prospect of technology for large-scale wind farm participating into power grid frequency regulation[J].Power System Technology,2014,38(3):638-646. [16]吴子双,于继来,彭喜云.高风速段次优功率追踪方式的风电调频方法[J].电工技术学报,2013,28(5):112-119. Wu Zishuang,Yu Jilai,Peng Xiyun.DFIG’s frequency regulation method only for high wind speed with suboptimal power tracking[J].Transactions of China Electrotechnical Society,2013,28(5):112-119. [17]Erlich I,Wilch M.Primary frequency control by wind turbines[C].IEEE Power and Energy Society General Meeting,Minnesota,USA,2010:1-8. [18]Estanqueiro A I,de Jesus J M F,Ricardo J,et al.Barriers (and solutions…) to very high wind penetration in power systems:the iberian case study[C].Power Engineering Society General Meeting,Berlin,Germany,2007:1-7. [19]IEEE Recommended Practice for Functional and Performance Characteristics of Control Systems for Steam Turbine-Generator Unit[S].IEEE Std.122-1991. [20]IEEE Recommended Practice for Preparation of Equipment Specifications for Speed-Governing of Hydraulic Turbines Intended to Drive Electric Generators[S].IEEE Std.125-2007. [21]Langnisso O.Incentives for grid-friendly wind power plants-examples from Spain and Germany[C].Proceedings of China-US Renewable Energy Grid Integration Workshop,Beijing,2010.
2015, Vol. 30 
