摘要
柔性直流输电系统广泛采用阻抗分析法研究其稳定性问题,模块化多电平换流器(MMC)的阻抗模型是应用该分析方法的基础。在实际工程中,正负序电流控制环和序分离算法是MMC控制系统的重要组成部分。研究表明,当采用基于延时对消的正负序分离算法时,柔性直流输电系统的交流阻抗会出现规律性波动现象,但目前对该波动现象的机理研究尚不充分。首先,在考虑正负序电流控制环和序分离算法的前提下推导了MMC的详细阻抗模型,展现了阻抗波动现象,进而研究了正负序电流环控制器参数的不一致性对该波动特性的影响。其次,推导了MMC的简化阻抗模型并验证了利用该模型分析阻抗波动现象的合理性。基于该简化模型,从理论上分析了阻抗波动现象的产生机理,并从理论上研究了交流阻抗波动会随着正负序电流环控制器参数不一致性的增加而进一步加剧的影响机理。最后,通过实验验证了上述理论分析的正确性。
Impedance analysis method is widely used to study the stability of modular multilevel converter based high voltage direct current transmission(MMC-HVDC)system.The impedance model of modular multilevel converter(MMC)is the basis of the application of this analysis method.In the practical engineering,the positive-negative sequence current control loops and the sequence separation algorithm are the important components of the MMC control system.The research shows that when the delaycancellation based positive-negative sequence separation algorithm is adopted,the AC impedance of the MMC-HVDC system will fluctuate regularly.However,the mechanism of this fluctuation phenomenon is not fully studied at present.Firstly,considering the positive-negative sequence current control loops and the sequence separation algorithm,this paper deduces the detailed impedance model of MMC,reproduces the impedance fluctuation phenomenon,and then studies the influence of the inconsistency of controller parameters of positive-negative sequence current loop on the fluctuation characteristics.Secondly,the simplified impedance model of MMC is deduced and the rationality of using this model to analyze the impedance fluctuation phenomenon is verified.Based on the simplified model,the generation mechanism of impedance fluctuation phenomenon is analyzed theoretically,and the influence mechanism on the aggravation of AC impedance fluctuation with the increase of the inconsistency of controller parameters of positive-negative sequence current loop is studied theoretically.Finally,experiments verify the correctness of the above theoretical analysis.
作者
尹太元
王跃
王晓雷
刘普
李风漠
孙杰
YIN Taiyuan;WANG Yue;WANG Xiaolei;LIU Pu;LI Fengmo;SUN Jie(State Key Laboratory of Electrical Insulation and Power Equipment(Xi’an Jiaotong University),Xi’an 710049,China;School of Electronic and Information,Zhongyuan University of Technology,Zhengzhou 450007,China;College of Electrical and Information Engineering,Zhengzhou University of Light Industry,Zhengzhou 450002,China)
出处
《电力系统自动化》
EI
CSCD
北大核心
2022年第10期149-158,共10页
Automation of Electric Power Systems
基金
国家电网公司科技项目(5100-202056393A-0-0-00)。
关键词
模块化多电平换流器
正负序电流控制
阻抗建模
稳定性分析
modular multilevel converter(MMC)
positive-negative sequence current control
impedance modeling
stability analysis
