a novel coordination control strategy for parallel-connected boost converters in dc microgrid

Since the constant power loads (cpls) have negative-impedance characteristics, the system damping of dc microgrid is reduced, which will lead to the collapse of bus voltage. in addition, the errors of current sharing within parallel-connected dc-dc converters amplify due to different line impedances. to address these issues, a hybrid coordination control strategy is proposed for parallel-connected boost converters, which realizes the stable control and maintains the accuracy of current distribution. firstly, a passivity-based control (pbc) with a proportional-integral (pi) regulator is developed for the boost converter with cpl. the virtual damping based pbc enhances the system damping and pi regulator eliminates the steady-state error caused by the variation of load. on this basis, a secondary voltage control (svc) featuring in simplicity and weak dependence on communication is introduced to remove the errors of current distribution. finally, a rt-lab-based hardware in the loop (hil) experimental platform is established and the experimental results verify the effectiveness of the proposed hybrid coordination control strategy.