  DC microgrids are getting more and more applications due to simple
converters, only voltage control and higher efficiencies compared to
conventional AC grids. Droop control is a well know decentralized control
strategy for power sharing among converter interfaced sources and loads in a DC
microgrid. This work compares the stability assessment and control of four
types of droops for boost converters using the concept of passivity. EN
standard 50388-2 for railway systems provides a reference to ensure system
stability in perspectives of converters and system integration. Low pass filter
(LPF) in the feedback of the droop control is used to ensure converter
passivity. Bus impedance is derived to ensure system passivity with less
conservativeness. Analytical approach for design of passive controller for all
four types of droops is verified through time domain simulations of a single
boost converter based microgrid feeding a Constant Power Load (CPL).
