摘要
为了解决高频隔离型AC-DC环节阻抗建模问题,提出一种电压源型变换器(voltage source converter, VSC)与LLC谐振变换器集成耦合设计成的高频隔离型AC-DC环节(voltage source converter cascade LLC resonant converter,VSC-LLC)直流侧小信号阻抗模型的建模方法,此方法首先结合在近似谐振点工作模式下LLC谐振变换器的恒增益电压钳位功能,实现单级统一控制策略,将VSC与LLC视为一级;在此基础上,结合基波近似法下LLC谐振变换器的4阶小信号模型,建立了VSC-LLC系统小信号模型,进而推导出直流侧阻抗模型,突破双级系统阻抗建模。最后基于Matlab/Simulink搭建VSC-LLC非线性时域仿真系统,仿真结果验证了所提VSC-LLC直流侧阻抗建模方法的正确性,并分析了电路参数和控制器参数对直流侧阻抗的影响,为基于高频隔离型AC-DC环节微电网的阻抗稳定性分析提供了理论基础。
In order to establish a model of impedance stability analysis for high frequency isolated AC-DC link, this paper proposes a modeling method of the DC side small-signal impedance of high frequency isolated AC-DC link(VSC-LLC) by integrated coupling design of voltage source converter(VSC) and LLC resonant converter. Firstly, the constant gain voltage clamping function of LLC resonant converter under the operating mode of approximate resonance point is combined to realize single-stage unified control strategy, and VSC and LLC are combined into one stage. Secondly, combined with the fourth-order small-signal model of LLC resonant converter under the fundamental wave approximation method, the small-signal model of VSC-LLC is established, and the DC side impedance model of the VSC-LLC is derived, by which the impedance modeling of the two-stage system is realized. Finally, a nonlinear time domain simulation model of VSC-LLC is established on the Matlab/Simulink. Simulation results have verified the correctness of the proposed DC side impedance modeling method, and the influences of circuit parameters and controller parameters on DC side impedance are also analyzed, which provides a theoretical basis for impedance stability analysis of microgrid based on high frequency isolated AC-DC link.
作者
朱帝
裴忠晨
刘闯
张艳
秦健飞
ZHU Di;PEI Zhongchen;LIU Chuang;ZHANG Yan;QIN Jianfei(College of Electrical Engineering,Northeast Electric Power University,Jilin 132012,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2021年第3期953-962,共10页
High Voltage Engineering
基金
国家重点研发计划(2017YFB0903300)
国家电网公司科技项目(SGTYHT/16–JS–198)。
