Real-time implementation of control for grid connected distributed energy storage

The growth of renewable energy resource integration into the electrical power network has led to an incremental increase in Distributed Energy Storage Systems (DESS). These DESS will need to provide a variety of grid support and energy management functions. Through real-time simulation, this paper investigates key requirements of a dedicated supervisory controller for DESS, where the supervisory and local control units are connected using a telecommunication network. The implementation of the DESS, converter, local controller and central controller on a Real-time Digital Simulator (RTDS) is performed, to study the effect of delays, jitter and packet loss through the telecommunications system. The paper investigates the trade-offs in technology and control for the DESS. A real-time digital simulation model of a grid connected DESS is tested on RTDS, with a defined state transition control logic. The supervisory controller implementation and its communication with the local controller is verified. The system is investigated in terms of communication between the controllers at supervisory and local levels, along with the telecommunication delays. The developed real-time digital simulation model facilitates the examination of supervisory central control mechanisms intended to coordinate local DESS units and their interplay with the telecommunications systems.