Optimized Droop Control Parameters for Effective Load Sharing and Voltage Regulation in DC Microgrids

Droop control method is a widely used technique for achieving load sharing in DC microgrid applications. Virtual output impedance (or droop gain) and voltage reference are the main control parameters typically selected based on the power ratings of the sources for proper load sharing. The performance of droop controller is affected significantly by the voltage drops across the transmission line impedances, resulting in a load sharing error and voltage degradation across the microgrid. In this article, a new optimization procedure is proposed to find the optimal droop parameters such that the effect of the line impedances is minimized. An optimization problem along with the required constrains is formulated as the combination of current sharing errors as well as the voltage degradation for various loading conditions. Particle swarm-based technique is then used to provide a solution for this optimization problem. The performance of the droop controller with the optimal droop parameters is verified through a simulation case study implemented on the MATLAB/Simulink environment.