Distributed Piecewise Droop Control of DC Microgrid with Improved Load Sharing and Voltage Compensation

Droop control is an essential part of primary control in hierarchical control paradigm of DC microgrid. However, the problem with basic droop control using constant virtual resistance is that higher current sharing accuracy was achieved at the cost of higher bus voltage deviation, and thus which will degrade power quality and system efficiency of DC microgrid. In this paper, a family of distributed piecewise droop control strategies (DPDC) are derived to overcome the shortcomings of basic droop control in primary control level where the droop curves are configured flexibly according to partitioned load regions, and as a result, both current sharing and voltage compensation will be improved simultaneously. The superior performance of the DPDC strategies are verified by hardware testing results.