Analysis of generalized droop control in medium and low voltage power electric grids

The grid impedance ratio R/X value is the starting point for several conventional studies, such as DC power flow calculations. The conventional studies can be replaced with more generalized studies, in which the grid impedance ratio plays an important role. This paper presents a generalized droop control approach without the requisite estimation of the grid impedance ratio. Instead of performing large mathematical calculations, in order to estimate the grid impedance ratio, it is assumed that this ratio maintains a constant impact on the generalized droop control in medium and low voltage power electric grids. In this paper the performances of such a generalized droop control approach are compared to the performances of the conventional droop control approach, observing a system with two parallel connected voltage source inverters. Simulation results figure out the great advantages in application of modified generalized droop control, compared to the conventional droop control - maintaining better voltage levels as well as a more reasonable power sharing behavior.