An off-line design methodology of droop control for multiple bi-directional distributed energy resources based on voltage sensitivity analysis in DC microgrids

Abstract

The analysis and design of droop control applied to a bi-directional distributed energy resources in a DC microgrid are presented. The effects of line resistance on the power sharing and voltage regulation performance are analysed. To interpret a complicated line configuration, a voltage sensitivity analysis is derived based on a power flow analysis. Based on this analysis, the droop control design methodology is proposed to improve the power sharing accuracy and voltage regulation performance. Stability analysis is performed to analyse the influence of the control parameters and line resistance on the stability of the controller. The design method is applied to the 5-bus meshed line network model with three bi-directional distributed energy resources, three loads, and two non-dispatchable distributed energy resources. The improved power sharing accuracy and voltage regulation performance are verified using PSCAD simulations and the experimental system.