  Due to the increasing popularity of DC loads and the potential for higher
efficiency, DC microgrids are gaining significant attention. DC microgrids
utilize multiple parallel converters to deliver sufficient power to the load.
However, a key challenge arises when connecting these converters to a common DC
bus: maintaining voltage regulation and accurate current sharing. Unequal cable
resistances can cause uneven power sharing and lead to power losses.
Conventional droop control methods, which employ a virtual resistor to address
this issue, have limitations in achieving good performance across the entire
converter operating range. This paper proposes a modified droop control
algorithm to address this issue. This method modifies the virtual resistor in a
way that ensures power sharing aligns with each converter-rated capacity. The
algorithm is simple to implement and uses local measurements to update the
droop gain. This paper presents simulation studies and experimental tests to
analyze the performance of the proposed method, considering scenarios with
equal and unequal converter ratings. The results successfully validate the
accuracy and effectiveness of this innovative approach.
