电力建设2025，Vol.46Issue(5)：12-23,12.DOI:10.12204/j.issn.1000-7229.2025.05.002
基于电网阻抗压降的构网型柔直换流器改进双闭环控制
Improved Dual Closed-Loop Control for Modular Multilevel Converters Based on Voltage Drop on Grid Impedance
摘要
Abstract
[Objective]As renewable power bases gradually expand from load centers to remote areas such as deep offshore,deserts,and barren lands,using grid-forming voltage source converter-based high voltage direct current(VSC-HVDC)transmission technology is a promising solution for integrating renewable power to the grid.Considering power quality and fault current limitations,current grid-forming control usually adopts a dual closed-loop structure of AC voltage and AC current.This control structure relies on the voltage-current integral relationship of the AC-side filter capacitor and grid current feedforward to achieve stable control of the AC voltage.However,the AC side of the modular multilevel converter(MMC)usually lacks a centralized filter capacitor,and obtaining AC-side current feedforward to decouple from the grid is difficult,leading to degraded AC voltage control performance.[Methods]To solve this problem,this study proposes a novel dual-closed-loop AC voltage-control strategy for grid-forming VSC-HVDC converters.The strategy does not rely on the AC capacitance but adjusts the AC voltage of the PCC by controlling the voltage drop on the grid impedance.[Results]Simulation verification based on PSCAD/EMTDC showed that,under the proposed control mode,the grid-forming MMC exhibited good operational stability and active/reactive power dynamic control performance under different grid conditions.[Conclusions]The proposed control strategy can effectively improve the AC voltage-AC current dual-closed-loop control performance,operational stability,and grid adaptability of grid-forming MMC.关键词
柔性直流输电(VSC-HVDC)/构网型控制/交流电压控制/模块化多电平变换器Key words
voltage source converter-based high voltage direct current(VSC-HVDC)/grid-forming control/AC voltage control/modular multilevel converter分类
信息技术与安全科学引用本文复制引用
刘杉,刘琪,朱琳,严俊,迟程缤,孙增杰..基于电网阻抗压降的构网型柔直换流器改进双闭环控制[J].电力建设,2025,46(5):12-23,12.基金项目
国家电网公司科技项目"弱同步支撑下交直流电网互联接口控制机理研究"(5100-202258494A-2-0-CB) This work is supported by the Science and Technology Project of State Grid Corporation of China(No.5100-202258494A-2-0-CB). （5100-202258494A-2-0-CB）
