Improved Current Sharing Performance by Dynamic Droop Scaling Technique in Multiple Power Systems

This paper presents a novel dynamic droop scaling (DDS) technique for paralleled power modules. The major concern is the uniform current distribution of each module in multiple power systems. The droop method relies on the slope characteristic of load regulation to achieve current sharing accuracy. Owing to the trade-off between error percentages of current sharing and output voltage variation, conventional droop technique can´t provide good load regulation and current balance at the same time. However, the proposed DDS technique can break through the limitation of the conventional droop method by the implementation of dual current sensing loops. The dual current sensing loops not only increase the droop gain but also compensate the extra output dropout voltage automatically according to the steeper slope value of the novel method. Simulation results verify the error percentage of current sharing accuracy can be improved from 42.5% to 8.2% by DDS technique.