计及交直流谐波传递的MMC-BTB系统阻抗特性分析及环流配合策略
Analysis of Impedance Characteristics and Circulating Current Coordination Strategy of MMC-BTB System Considering AC and DC Harmonic Transmission
罗永捷 1段修超 1黄鹏 1王强钢 1周念成1
作者信息
- 1. 输配电装备及系统安全与新技术国家重点实验室(重庆大学),重庆市 沙坪坝区 400044
- 折叠
摘要
基于模块化多电平换流器的背靠背系统(back-to-back system based on modular multilevel converter,MMC-BTB)中换流器间控制交互密切,导致振荡事故频发.现有研究中忽略谐波传递的单端模型无法准确刻画MMC-BTB阻抗特性,也较少从振荡抑制层面考虑两换流器间的协同配合.为此,该文考虑 MMC-BTB 中换流器间谐波传递与衰减机理,依据多种环流控制方式的阻抗等价性提出一种基于环流协调控制的振荡抑制策略.首先,基于等效电路定性分析谐波的流通路径,并定量推导 MMC-BTB 的双端模型;然后,沿谐波路径对两侧环流控制的交互机理开展分析,证明其对改善 MMC-BTB 阻抗特性的关键作用,并提出环流控制的协调配合与参数优化策略;最终,通过 Matlab/Simulink 仿真验证理论分析与所提策略的正确性.
Abstract
The back-to-back system based on modular multilevel converter(MMC-BTB)has close control interaction between converters,which leads to frequent oscillation accidents.In the existing research,the single-station model ignoring harmonic transmission cannot accurately describe the impedance characteristics of MMC-BTB,and the coordination between the two converters is less frequently considered from the perspective of oscillation suppression.Therefore,this paper considers the mechanism of harmonic transmission and attenuation between converters in MMC-BTB,and proposes an oscillation suppression strategy based on the impedance equivalence of various circulation control methods.First,the flow path of harmonic is qualitatively analyzed based on the equivalent circuit,and the double-station model of MMC-BTB is derived quantitatively.Then,the interaction mechanism of the circulation control on both stations along the harmonic path is analyzed,which demonstrates its key role in improving the impedance characteristics of MMC-BTB,and proposes a strategy for coordination and parameter optimization of circulation control.Finally,the correctness of the theoretical analysis and the proposed strategy is verified through Matlab/Simulink.
关键词
背靠背系统/谐波传递/阻抗特性/环流控制/协调配合Key words
back-to-back system/harmonic transmission/impedance characteristic/circulation control/coordination and cooperation引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据