ENERGY MANAGEMENT AND CONTROL STRATEGY FOR DC MICRO-GRID IN DATA CENTER

摘要

DC micro-grid,as a self-management grid form of integrating distributed energy systems with utility power systems,will efficiently realize the value and benefit of the distributed energy resources.In this paper,the DC micro-grid mainly consists of five parts: a PV source,a DC/DC converter,a battery energy storage unit,a bi-directional DC/DC,and a bi-directional DC/AC which is connected to the main grid.This DC micro-grid has different control strategies according to different operating modes (grid connected,islanded).Then its control mode is designed and investigated by MATLAB/Simulink models.The simulation results verify the validity of the mathematical model and the feasibility of the proposed control strategies.In the grid connected mode,the transfer energy can flow in bi-directional modes,and DC bus voltage level can be stabilized by DC/AC converter.In the islanded mode,the battery converter serves as a voltage source to ensure a stable DC voltage.At last,DC micro-grid experimental system is used to examine its switching functions among different control modes.The experimental results demonstrate that high quality power can be supplied.