基于Ostrowski圆盘定理的并网逆变器系统稳定性分析

并网逆变器与电网之间的相互作用是影响并网系统稳定运行的因素之一，针对并网逆变器系统的稳定性问题，提出了一种并网逆变器系统稳定性的快速判定方法。首先基于阻抗分析方法得到并网逆变器系统的回率矩阵。其次基于Ostrowski圆盘定理得到回率矩阵的特征值轨迹Ostrowski带，并根据Ostrowski稳定判据判断系统稳定性。最后在MATLAB/Simulink中搭建仿真模型，并构建实验平台。仿真和实验结果表明该稳定判据能够有效判定系统是否处于稳定状态，并且可以快速估计并网逆变器系统的参数稳定域，为系统参数的选取提供判断依据。

Stability analysis of grid-connected inverter system based on Ostrowski disc theorem

The interaction between grid-connected inverter and power grid is one of the factors that affect the stable operation of grid-connected system. Aiming at the stability of grid-connected inverter system, a fast method to determine the stability of grid-connected inverter system is proposed. Firstly, the return rate matrix of grid-connected inverter system is obtained based on impedance analysis method. Secondly, based on the Ostrowski disc theorem, the characteristic root locus Ostrowski band of the return rate matrix is obtained, and the stability of the system is judged according to the Ostrowski stability criterion. Finally, the simulation model is built in MATLAB/Simulink, and the experimental platform is built. The simulative and experimental results show that the stability criterion can effectively determine whether the system is in a stable state, and can quickly estimate the parameter stability region of grid-connected inverter system, thus providing the judgment basis for the selection of system parameters.