Load Profile-Based Setpoint Design for Piecewise Droop Controller to Mitigate Current Sharing Error in Dual Active Bridge System

Abstract

Effective load current distribution is a fundamental aspect of ensuring a stable and efficient DC microgrid operation particularly when utilizing dual active bridge converters. In order to construct an improved piecewise setpoint, this research involves a thorough analysis of the statistical distribution of load profiles and the intrinsic properties of a two-segment piecewise droop controller. Furthermore, a thorough comparison analysis of linear and exponential droop-based approaches is carried out in this paper. To assess the proposed two-segment piecewise droop controller, several simulations and hardware-in-loop scenarios are carried out. Additionally, the conventional discrete piecewise droop control method is compared with the proposed method. Notably, with the proposed method, paralleling dual active bridge converters in a DC microgrid clearly demonstrates a significant improvement in current sharing within a specific operating range. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.