Design and Analysis of a Standalone DC Microgrid with Battery and Fuel Cell Energy Storage Penetration for Different Load Characteristic

The technological development of energy storage and integration of renewable energy to the power system open up the need of using more controllable and flexible energy sources. Since most of the intermittent energy sources are arbitrarily located, controlling them locally will enhance power system stability and optimal use of distributed energy.This paper presents a distributed control system of energy storage devices connected with a standalone DC microgrid. The energy storage devices consist of two Nickel-Metal-Hydride batteries and a hydrogen fuel cell. A decentralized charge controller is presented in this paper. The main idea is to use decentralized charge control to reduce the bus voltage variation in the microgrid and to utilize the storage devices optimally. In this model, the storage devices can share the load power equally. To understand and validate the model, resistive and inductive load have been connected to the DC microgrid. Different characteristics of power, voltage,and current of the storage system for different load profile is observed and controlled by a PI controller designed based on the mathematical model presented in this paper. The performance of the proposed model is tested and verified in Matlab/Simulink environment.