单相并网储能双向变流器线性时间周期模型的稳定性分析

Stability analysis of linear time periodic model for single-phase grid-connected power conversion system

针对传统线性时不变模型无法描述储能双向变流器多频次谐波间交互耦合现象的问题,提出了一种单相并网储能双向变流器的线性时间周期模型,并进行稳定性分析。基于线性时间周期理论对单相并网储能双向变流器进行建模,得到非线性时间周期模型;围绕周期轨道将该模型线性化,得到储能双向变流器的线性时间周期时域模型;通过傅里叶展开推出了储能双向变流器的线性时间周期频域模型;利用李雅普诺夫第一方法分析比例积分控制器在不同参数下的储能双向变流器小信号模型的稳定性及稳定边界。MATLAB/Simulink仿真实验结果表明:建立的单相并网储能双向变流器的线性时间周期模型具有准确性和稳定性,稳定性边界正确。

Aiming at the problem that the traditional linear time invariant model can not describe the interaction between multi-frequency harmonics in the power conversion system,a linear time period model of single-phase grid-connected power conversion system was proposed,and the method of row stability was selected.Firstly,the single-phase grid-connected power conversion system was modeled based on the linear time period theory,and a nonlinear time period model was obtained.Then,the model was linearized around the periodic orbit to get the linear time period time domain model of power conversion system;Meanwhile,the linear time periodic frequency domain model of power conversion system was derived by Fourier expansion.Finally,the stability and stability boundary of power conversion system small signal model under different parameters of proportional-integral controller were analyzed by Lyapunov first method.The MATLAB/Simu1ink simulation results showed that the established linear time periodic model for single-phase grid-connected power conversion system had accuracy and stability,and the stability boundary was correct.