摘要
基于低频中压交流(LF-MVac)互联微电网的低频互联线路某一相退出运行时,其核心装备隔离型模块化多电平矩阵变换器(I-M3C)需要具备低频两相运行能力。若此时工频弱电网发生电压跌落,I-M3C同时需要具备主动电压支撑能力。介绍了基于LF-MVac互联微电网系统架构以及核心装备拓扑。分析了LF-MVac互联线路的两相运行特征,探究了工频弱电网故障期间虚拟同步发电机(VSG)故障电流的影响因素。结合基于虚拟正交量的单相dq变换设计了LF-MVac两相运行控制策略,利用同步机三阶模型设计了VSG控制策略,为工频弱电网提供主动支撑,并通过动态调节有功参考值实现故障电流抑制。在MATLAB/Simulink中搭建了10 kV/2 MW的I-M3C仿真平台,验证了I-M3C工/低频端口带故障运行控制策略的有效性。
In microgrids interconnected by low-frequency medium-voltage alternating current(LF-MVac),when one phase of the low-frequency interconnection line is out of operation,as its key equipment,the isolated modular multilevel matrix converter(I-M3C)needs to have the low-frequency two-phase operation abilility.If voltage drops in the power frequency weak grid during this moment,the I-M3C also needs to have the active voltage support abilility.The system architecture and key equipment topology of the interconnected microgrids based on LF-MVac are introduced.The two-phase operation characteristics of the LF-MVac inter⁃connection line are analyzed,and the factors affecting the fault current of the virtual synchronous generator(VSG)during fault in the power-frequency weak grid are explored.The control strategy of LF-MVac twophase operation is designed by a single-phase dq transformation based on virtual orthogonal quantities.Utilizing the third-order model of the synchronous machine,a VSG control strategy is designed to provide active support for power-frequency weak grids.And the fault current suppression is achieved through the dynamic regulation of the active power reference value.A 10 kV/2 MW I-M3C simulation platform is estab⁃lished in MATLAB/Simulink to verify the effectiveness of the control strategy for the fault operation at its power/low-frequency ports of I-M3C.
作者
朱帝
王菁月
刘闯
裴忠晨
孙赫阳
ZHU Di;WANG Jingyue;LIU Chuang;PEI Zhongchen;SUN Heyang(School of Electrical Engineering,Northeast Electric Power University,Jilin 132012,China;School of Electrical Engineering,Dalian University of Technology,Dalian 116024,China)
出处
《电力自动化设备》
北大核心
2026年第2期94-101,184,共9页
Electric Power Automation Equipment
基金
国家自然科学基金资助项目(52477178)。
关键词
隔离型模块化多电平矩阵变换器
低频中压交流
互联微电网
两相运行
虚拟同步发电机
故障电流抑制
isolated modular multilevel matrix converter
low-frequency medium-voltage alternating current
interconnected microgrids
two-phase operation
virtual synchronous generator
fault current suppression
