多逆变器并联系统暂态稳定性分析及其暂态电流注入策略  

Transient Stability Analysis and Transient Current Injection Strategy of Multi-inverter Parallel System

作　　者：王继磊 张兴[1] WANG Jilei;ZHANG Xing(National and Local Joint Engineering Laboratory for Renewable Energy Access to Grid Technology,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]合肥工业大学可再生能源接入电网技术国家地方联合工程实验室,合肥230009

出　　处：《高电压技术》2025年第1期390-400,I0045,I0046,共13页High Voltage Engineering

基　　金：国家重点研发计划(2022YFB4202301)。

摘　　要：在电网故障期间,逆变器之间以及逆变器与电网之间的交互作用易引发多逆变器并联系统暂态稳定性问题。此外,以往的逆变器暂态稳定性分析结果与改进策略的研究对象大多为单逆变器并网系统,可能并不适用于多逆变器并联系统。针对这一问题,首先建立了多逆变器并联系统暂态同步模型,指出多机交互作用会改变系统平衡点存在性和暂态特征参数。然后,在不同电网故障初始状态和逆变器输出特性下,采用等面积准则和相平面图分析了多机交互作用对系统暂态稳定性的影响规律。基于此,提出了一种实现电网故障前后平衡点近似恒定的暂态电流注入策略,以确保各逆变器暂态稳定运行,为电网故障期间暂态电流的设置提供参考。最后,基于Matlab/Simulink仿真软件和实验平台进行了仿真和实验验证,结果表明所提暂态同步模型能够准确反映系统暂态响应特性,所提策略能够最大化系统暂态稳定裕度。During grid faults,the interaction between inverters and between inverters and the grid can easily lead to tran-sient stability problems in the multi-inverter parallel system.In addition,most of the research objects of previous inverter transient stability analysis results and improvement strategies are single-inverter grid-connected systems,which may not be applicable to the multi-inverter parallel system.Aiming at this problem,we first established a transient synchronization model of the multi-inverter parallel system,and pointed out that multi-inverter interaction would change the equilibrium point existence and transient characteristic parameters.Then,under different grid fault initial states and inverter output characteristics,the influence of multi-inverter interaction on system transient stability was analyzed by using the equal-area criterion and the phase portrait.Based on this,a transient current injection strategy was proposed to realize the approximately constant equilibrium point before and after the grid fault to ensure the transient stable operation of each inverter and provide a reference for the setting of the transient current during the grid fault.Finally,simulation and ex-perimental verification were conducted based on Matlab/Simulink simulation software and experimental platform.The results show that the proposed transient synchronization model can accurately reflect the system’s transient response characteristics,and the proposed strategy can maximize the system's transient stability margin.

关 键 词：多逆变器并联系统 暂态稳定性 多机交互作用 暂态电流注入策略 电网故障 平衡点存在性 

分 类 号：TM464[电气工程—电器] TM712