面向即插即用工况的多虚拟同步发电机控制参数自适应协调优化策略

Adaptive coordination and optimization strategy for control parameters of multi-virtual synchronous generators in plug and play working conditions

随着大规模新能源发电通过逆变器并网,系统惯量和阻尼特性不断变弱严重影响运行稳定性。虚拟同步发电机技术是解决这一问题的重要手段之一。文中以多虚拟同步发电机并联系统作为研究对象,建立了通用的小信号模型,分析了新能源发电即插即用需求下系统模型中各变量的对应关系,提出一种适应多虚拟同步发电机灵活组网运行时的参数自适应优化方法。进一步采用根轨迹法分析了控制参数变化对系统稳定性的影响,提出参数选取的指导原则并给出了建议的取值方案,降低了在即插即用工况下给系统带来的功率振荡和频率波动,并提高了系统的分配功率精度。最后,在Matlab/Simulink平台上建立了模型,对文中的分析方法和参数优化策略的可行性及有效性进行了验证。

Virtual synchronous generator technology is one of the important means to solve the problems of low inertia and underdamping when large-scale new energy power generation is connected to the grid. However,the amount of renewable energy power generation is large,and the off-grid and grid-connected are more frequent,so the stability of the system faces great challenges. The multiple parallel systems of the virtual synchronous generator are taken as the research object. A general smallsignal model of multiple virtual synchronous generator grid-connected systems is established,and the corresponding relationship of variables in the system model under the plug-and-play demand of new energy power generation is analyzed. A parameter adaptive optimization method is proposed to adapt to the flexible parallel network operation of multiple virtual synchronous generators. Furthermore,the root locus method is used to analyze the influence of the change of control parameters on the system stability,and the guiding principles for parameter selection and the suggested value selection scheme are proposed to reduce the impact of power oscillation and frequency fluctuation under the plug-and-play working condition,and improve the power allocation accuracy of the system. A simulation model is established on the Matlab/Simulink platform. The testing results verify the feasibility and effectiveness of the analysis method and parameter optimization strategy proposed in this paper.