基于直流电压动态修正的柔性多状态开关自适应下垂控制  

Adaptive Droop Control of Flexible Multi-state Switch Based on DC Voltage Dynamic Correction

作　　者：马文忠[1] 刘晓丽[1] 王玉生[2] 孟繁丞 刘星宇 李佳慧 MA Wenzhong;LIU Xiaoli;WANG Yusheng;MENG Fancheng;LIU Xingyu;LI Jiahui(Institute of New Energy,China University of Petroleum(East China),Qingdao 266580,China;Petro China Planning and Engineering Institute,Beijing 100083,China)

机构地区：[1]中国石油大学(华东)新能源学院,青岛266580 [2]中国石油天然气股份有限公司规划总院,北京100083

出　　处：《高电压技术》2024年第6期2673-2681,共9页High Voltage Engineering

基　　金：国家自然科学基金(52277208)。

摘　　要：为了满足配电网的多种互联需求,柔性多状态开关(flexible multi-state switch,FMSS)已衍生出多种互联应用的技术形态,多端FMSS与双端FMSS相比更具经济性和可靠性,已成为研究热点。传统下垂控制通过改变直流侧电压实现不平衡功率的消纳,但直流侧电压的偏离会影响系统安全可靠运行。针对模块化多电平换流器(modular multilevel converter,MMC)的多端FMSS系统,提出了一种改进型下垂控制策略,根据换流器消纳的有功功率实时动态改变直流电压的参考值和下垂增益,实现了直流电压的无偏差运行,既能避免换流站过载,又能解决不平衡功率消纳引起的电压偏离问题,提高了系统的稳定性。另外,由于MMC自身结构特性和PI参数整定困难,将传统的电流内环改为模型预测控制,并采用典型的二阶Runge-Kutta法对状态方程进行离散化,提高了控制精度。最后基于MATLAB/Simulink仿真软件搭建了四端FMSS系统模型,验证了所提控制策略的可行性与有效性。In order to meet various interconnection requirements of distribution network,flexible multi-state switch(FMSS)has derived a variety of technical forms for interconnection applications.Multi-terminal FMSS is more economical and reliable than dual-terminal FMSS,and has become a research hotspot.Traditional droop control can absorb unbalanced power by changing DC side voltage,but the deviation of DC side voltage will affect the safe and reliable operation of the system.Aiming at the multi-terminal FMSS system modular multilevel converter(MMC),we propose an improved droop control strategy,which dynamically changes the reference value of DC voltage and droop gain in real time according to the active power ingestion of the converter,thus realizing the unbiased operation of DC voltage.It can not only avoid the overload of converter station,but also solve the problem of voltage deviation caused by unbalanced power absorption,and improve the stability of the system.In addition,due to the structural characteristics of MMC itself and the difficulty of PI parameter setting,the traditional current inner loop is changed into model predictive control,and a typical second-order Runge-Kutta method is used to discretize the equation of state,which improves the control accuracy.Finally,a four-terminal FMSS system model is designed based on MATLAB/Simulink simulation software to verify the feasibility and effectiveness of the proposed control strategy.

关 键 词：柔性多状态开关(FMSS) 模块化多电平换流器(MMC) 直流电压动态修正 自适应下垂控制 改进型下垂控制 协同优化控制 

分 类 号：TM721.1[电气工程—电力系统及自动化]