不平衡电网电压下双馈感应发电机系统串联和并联网侧变换器协调控制策略  

Coordinated Control Strategy of Series and Parallel Grid Side Converters for DFIG System under Unbalanced Grid Voltage

作　　者：康祎龙 郑婷婷 苗世洪 刘子文[1,2] 刘昱良 Kang Yilong;Zheng Tingting;Miao Shihong;Liu Ziwen;Liu Yuliang(State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology,Wuhan,430074,China;Hubei Electric Power Security and High Efficiency Key Laboratory Huazhong University of Science and Technology,Wuhan,430074,China;State Grid East Inner Mongolia Electric Power Company Limited Electric Power Research Institute Hohhot,010020,China)

机构地区：[1]华中科技大学电气与电子工程学院强电磁工程与新技术国家重点实验室,武汉430074 [2]华中科技大学电力安全与高效湖北省重点实验室,武汉430074 [3]国网内蒙古东部电力有限公司电力科学研究院,呼和浩特010020

出　　处：《电工技术学报》2018年第A01期193-204,共12页Transactions of China Electrotechnical Society

基　　金：国家重点研发计划(2017YFB0903601);国家自然科学基金(51777088);2018年内蒙古东部电力有限公司科技项目(SGMDDK00DJJS1800053)资助

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.

关 键 词：不平衡电网电压 双馈感应发电机 串联网侧变换器 2 倍频波动 降阶谐振控制器 

分 类 号：TM614[电气工程—电力系统及自动化] TM46