Comparison of basic droop control with linear and nonlinear internal control of boost converters feeding resistive load

Abstract

Droop control method is largely adopted to achieve load sharing among paralleled converters in standalone DC microgrid. However, this control is often associated with a lower layer of control performed using PI controllers. These PI controllers are used to control the inductor current and output voltage of the converters, although these latter being nonlinear systems and despite the variability of production and consumption on renewable sources-based DC microgrid. Hence, in this paper, the authors address the comparison of the application of basic droop control when the lower layer of control is performed using PI controllers or using nonlinear controllers. The comparison is applied to a system including two distributed generators interfaced to the DC bus by non-isolated boost converters. The modeling of the converter and the details of the synthesis of the different controllers are detailed. Simulation results are then presented using PSIM software.