The coordinated control strategies of a DC grid with energy storage system for renewable energy integration

DC grid is considered to be one of the efficient technologies to collect and transmit large-scale renewable energy. The paper investigates the coordinated control and operation issues of a DC grid equipped with energy storage system for renewable energy integration, and proposes the coordinated control strategies of start up/shut down and normal operation of such a DC grid. The steady and smooth power output in the AC receiving terminals can be achieved through the coordinated control between renewable energy and energy storage system, taking into consideration of the fluctuation output characteristics of the renewable energy generation and the load shifting function of energy storage system. Case studies are carried out in the simulation platform PSCAD/EMTDC, and results validate the correctness of the proposed strategies.