Power management of heterogeneous autonomous DC microgrid system with EVs using modified SoC reference based DC bus voltage control

Due to stochastic and intermittent nature of distributed generation (DG) sources, different types of nonlinear loads, different transmission lines and heterogeneous energy storage devices (ESDs) the direct current (DC) microgrid (MG) system becomes complex and diverse in nature. The battery module of different capacities, different types, different age and of different state of charge (SoC) makes the system heterogeneous. With the traditional droop control method, characteristics of the system parameters are homogeneous in nature which neglect the dynamics of different distributed energy resources (DERs) and ESDs. If multiple DERs are present, the dynamics and characteristics of different DERs would be different since the environment is dynamically varying in nature. In this article, modified SoC reference based droop control technique to examine the complex and heterogeneous autonomous DC MG system operation considering multiple DGs is presented. The controller implemented in this paper regulates the DC bus voltage on the basis of interconnected battery bank SoC and it also ensures equal load/power sharing between heterogeneous battery banks and neighbour nodes. The effectiveness of the proposed DC MG system with modified droop controller has been validated by MATLAB/Simulink environment. The simulation result validates the approach presented for hetrogeneous MG system with regulation of DC bus voltage with effective power sharing.