Enhanced distributed secondary control method for DC microgrids against heterogeneous communication time delays

Accurate power sharing in a DC microgrid with a conventional distributed control scheme is impossible to achieve due to the heterogeneity of communication time delays. To address this problem, an anti-heterogeneous time delay estimator is proposed on the basis of scattering transformation and a PI consensus algorithm, and proper power allocation is achieved along with voltage compensation in a distributed fashion. In the proposed estimator, transmitted/received signals are modified via scattering transformation, and average consensus is estimated by the PI consensus algorithm. Consequently, proportional power sharing and voltage compensation are achieved concomitantly despite heterogeneous temporal delays, mismatched line resistances, and load variation. The effectiveness of the proposed method is evaluated through experiments.