基于纵横交叉算法的直流微电网趋优稳定性分析

Optimal Stability Analysis of DC Microgrid Based on Crisscross Optimization Algorithm

在直流微电网稳定性分析中,为解决多指标趋优化运行提高系统稳定性问题,提出了一种纵横交叉算法(crisscross optimization algorithm,CSO)求解参数趋优解方法,该算法能够实现全局并行搜索,有效地规避参数局部解对稳定性分析的影响。首先建立多源多负荷直流微电网的小信号模型,利用特征根分析方法计算出系统主导模态,通过参与因子法解耦状态变量对主导模态的影响程度,将主导模态实部作为CSO的目标函数并引入条件约束的惩罚函数进行稳定性分析。通过CSO的搜索优化能力找寻到电源下垂系数趋优解,以此增大阻尼、提高系统稳定性,并利用CSO发现源侧线路采用两长一短输电也可提高系统稳定性。最后,通过仿真分析和实验验证所提控制策略的正确性与有效性。

In the stability analysis of DC microgrid,a crisscross optimization algorithm(CSO)is proposed to solve the problem of improving system stability by multi-index optimization operation.CSO algorithm can realize global parallel search and effectively avoid the influence of parameter local solution on stability analysis.In this paper,a small signal model of multi-source and multi-load DC microgrid is established.The dominant mode of the system is calculated by eigenvalue analysis.The influence degree of state variables on dominant modes is decoupled by the participation factor method.The real part of the dominant mode is taken as the objective function of CSO,and the penalty function with conditional constraints is introduced to analyze the stability.The optimal solution of power supply droop coefficient is found through the search and optimization ability of CSO,so as to increase the damping and improve the stability of the system.By using CSO,it is found that the system stability can also be improved by using two-long-and-one-short transmission line at the source-side.Finally,the effectiveness and correctness of the proposed control strategy are verified by simulation analysis and experiments.