An adaptive droop based cooperative control framework in DC microgrids

Abstract

This paper discusses about a cooperative secondary control strategy for accurate load sharing in DC microgrids. Since accuracy in DC voltage regulation and power sharing can't be achieved simultaneously in a non-negligible impedance network, an adaptive droop has been proposed to address proportionate power sharing of distributed DC sources via a secondary controller. A fixed droop along with a secondary controller generally introduces a loading mismatch between converters while accomplishing voltage regulation at load bus. Hence, an adaptive droop has been proposed to improve power sharing along with a tertiary update used for fine-tuning. Further, a voltage observer has been used to achieve global average voltage regulation at all source buses. The performance of the proposed control strategy is validated in MATLAB/SIMULINK environment for various communication as well as converter adversities.