弱电网下提高并网变流器稳定性的导纳重塑方法  

Admittance Reshaping Method for Improving the Stability of Grid-tied Converter in Weak Grid

作　　者：唐欣[1] 李珍 唐凯璇 何洋 屈贝 岳雨霏 TANG Xin;LI Zhen;TANG Kaixuan;HE Yang;QU Bei;YUE Yufei(State Key Laboratory of Disaster Prevention&Reduction for Power Grid(Changsha University of Science and Technology),Changsha 410114,Hunan Province,China)

机构地区：[1]电网防灾减灾全国重点实验室(长沙理工大学),湖南省长沙市410114

出　　处：《中国电机工程学报》2024年第15期6123-6135,I0024,共14页Proceedings of the CSEE

基　　金：国家自然科学基金项目(52377167,51977013,52207186)。

摘　　要：并网变流器接入弱电网易发生振荡问题,基于无源性理论提出一种导纳重塑控制策略来提高系统稳定性能,使并网系统在中低频段不受电网等值阻抗的影响。首先,为了便于构造严格正实的变流器导纳矩阵,将变流器导纳模型分解为两个子系统进行分析,找出可重塑的控制环节;然后,基于正实方法设计了外环重塑矩阵M和内环重塑矩阵N,使并网系统在中低频段内渐进稳定。此外,导纳重塑后的系统是一个对称系统即单输入单输出系统,可方便求取系统的稳定裕度。仿真和实验均验证了所提导纳重塑方法在提高系统稳定性和简化系统稳定性分析的可行性和有效性。A grid-tied converter connected to weak grid is prone to cause oscillation problems in the grid-tied system.Therefore,this paper proposes an admittance reshaping control strategy based on passivity theory to improve system stability performance,so that the grid-tied system is not affected by the equivalent impedance of the grid in low and middle frequency bands.First,in order to facilitate the construction of a strictly positive real converter admittance matrix,the converter admittance model is decomposed into two subsystems for analysis to identify reconfigurable control links.Then based on the positive real method,the outer loop remodeling matrix M and the inner loop remodeling matrix N are designed to gradually stabilize the grid connected system in the middle and low frequency bands.In addition,the admittance remodeling system is a symmetric system(a single-input single-output system),which simplifies the analysis of stability and resonance problems in the case of multiple converters.Both simulation and experiment verify the feasibility and effectiveness of the proposed admittance remodeling method in improving system stability and simplifying system stability analysis.

关 键 词：弱电网 正实方法 导纳重塑 系统稳定性 单输入单输出 

分 类 号：TM46[电气工程—电器]