摘要
分析并网变流器引起的中高频振荡时,若忽略锁相环(PLL)的影响,可简化变流器模型,从而简化系统稳定性分析。为定量可忽略PLL影响的频段,建立了考虑PLL以及忽略PLL的交流侧输出导纳模型,分析了PLL对变流器交流侧导纳模型的影响。对比分析两个导纳模型之间的差异,从控制带宽的视角,提出了在小信号稳定性分析中忽略PLL影响的前提条件,以及忽略PLL影响频段的起始频率点的计算方法,进而实现简化系统的导纳模型。最后,通过仿真和实验分析了考虑PLL以及忽略PLL对系统稳定性分析的影响,验证了理论分析的正确性。
When analyzing the medium-high frequency oscillation caused by the grid-connected converter,if the influence of phase locked loop(PLL)is neglected,the converter model can be simplified and the system stability analysis can be simplified.In order to quantify the frequency band in which the PLL influence can be ignored,the output admittance model of AC side considering PLL and ignoring PLL is established,and the influence of PLL on the admittance model of AC side of converter is analyzed.The differences between the two admittance models are compared and analyzed,from the perspective of control bandwidth,the preconditions of neglecting the influence of PLL in the stability analysis of small signal and the calculation method of neglecting the initial frequency point of PLL influence band are proposed,and then the admittance model of simplified system is realized.Finally,the influence of considering PLL and ignoring PLL on system stability analysis is analyzed by simulation and experiment,and the correctness of theoretical analysis is verified.
作者
唐欣
何洋
李珍
李勇
TANG Xin;HE Yang;LI Zhen;LI Yong(Changsha University of Science&Technology,Changsha 410114,China)
出处
《电力电子技术》
CSCD
北大核心
2022年第8期27-31,共5页
Power Electronics
基金
国家自然科学基金(51977013)。
关键词
并网变流器
锁相环
导纳模型
稳定性分析
grid-connected converter
phase locked loop
admittance model
stability analysis
