微网运行模式无缝切换控制技术研究

Research on seamless switching control technology of micro-grid operation mode

微网有并网和离网两种运行模式,实现两种运行模式间的无缝切换是保障系统稳定运行的关键。文中首先介绍了微网的系统模型与工作模式,然后分别介绍了基于虚拟同步发电机(VSG)的无缝切换控制技术和基于下垂控制(droop control)的无缝切换技术,最后在PSCAD中搭建了微网系统的仿真模型,验证两种控制技术的可行性,对比分析了两个切换过程的控制效果,由仿真结果得出基于VSG的无缝切换控制策略更适用于微网的并离网切换。

There are two kinds of grid-connected and off-grid working mode of micro-grid,and the achievement of seamless switching between the two modes of operation is to ensure the stable operation of the system key.Firstly,the system model and working mode of micro-grid are introduced.Then,the seamless switching control technology based on virtual synchronous generator(VSG)and the seamless switching technology based on droop control are introduced respectively.Finally,the simulation model of the micro-grid system is validated to verify the feasibility of the two control technologies.The control effects of the two handover processes are compared and analyzed.According to the simulation results,the seamless switching control strategy based on VSG is more applicable to the grid-connected and off-grid handover of the micro-grid.