Comparative Analysis of Droop Control Techniques for Voltage Stability in DC Microgrids

The main control objective in stand-alone DC microgrids is to keep constant the DC bus voltage. When droop control is adopted, several generation units participate in DC voltage control. The objective of this work is to evaluate the control performances of droop control techniques. A comparative analysis is performed for two mode of droop control; the voltage droop mode (V-I) and the current/voltage mode (I-V). The micro-grid operation with the two control techniques was simulated considering rapid variation of the loads in order to investigate voltage stability. The Voltage Deviation Index (VDI) and the Load sharing equilibrium were used to measure the control performances with the two control methods.