一种抑制风电送出直流MMC内部振荡的零序电流控制策略研究  

Research on zero sequence current control strategy for suppressing internal oscillation of DC MMC send by wind power

作　　者：兰月 王俊芳 窦宇宇 王新宇 杨熠 刘荣顺 LAN Yue;WANG Junfang;DOU Yuyu;WANG Xinyu;YANG Yi;LIU Rongshun(Electric Power Research Institute of State Grid Inner Mongolia Eastern Electric Power Co.,Ltd.,Hohhot 010020,China;School of Automation,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]国网内蒙古东部电力有限公司电力科学研究院,内蒙古呼和浩特010020 [2]武汉理工大学自动化学院,湖北武汉430070

出　　处：《电力科学与技术学报》2024年第1期234-242,共9页Journal of Electric Power Science And Technology

基　　金：国网内蒙古东部电力有限公司科技项目(526604220007)。

摘　　要：量化分析了风电经直流送出系统的振荡模式及各振荡模式与系统状态变量之间的关系,揭示了模块化多电平换流器(modular multilevel converter,MMC)系统内部振荡的环流零序分量与电容电压的交互影响机理;基于该机理,构建了MMC系统各桥臂等效电容储存总能量与零序电流的动态关系模型,推导了MMC系统各桥臂等效电容储存总能量与电容电压差模量以及共模量的表达式,提出了零序电流控制策略;以该控制策略动态模型为对象,计及该动态模型中间变量后,对含零序电流控制策略MMC系统的振荡模式进行了分析,结果表明,所提控制策略可以使振荡模式的实部向左移动,增加总阻尼,提升系统稳定性。In this paper,the oscillation mode of wind power through DC transmission system is analyzed,and the interaction mechanism between the circulating current zero sequence component of MMC system internal oscillation and capacitor voltage is revealed.The mechanism of the internal oscillation of MMC system caused by the interaction between the zero sequence component of the circulating current and the capacitor voltage of MMC is revealed.The dynamic relationship between the total energy stored by the equivalent capacitance of each arm of the MMC system and the zero-sequence current is constructed.The differential modulus and the common modulus of the total energy stored by the equivalent capacitance of each arm of the MMC system are derived.The zero-sequence current control strategy is proposed.The dynamic model of the control strategy is constructed,and the oscillation mode of MMC system with zero sequence current control strategy is analyzed after considering the intermediate variables of the model.The results show that the proposed control strategy can make the real part of the oscillation mode move left and increase the total damping.The electromagnetic transient simulation model of wind power through DC transmission system with zero sequence current control strategy is constructed.The simulation results show that the proposed strategy greatly increases the damping level of the system,improving the stability.

关 键 词：振荡机理 电容存储能量 参与因子 零序电流控制 

分 类 号：TM863[电气工程—高电压与绝缘技术]