Average Voltage Observer Based Distributed Secondary Sliding Mode Control with Reactive Power Sharing for Microgrids

Abstract

Combining distributed power generation units into self-operating islanded microgrids is conducive to improving the penetration rate of new energy power generation. However, the impedance mismatch leads to the contradiction between voltage regulation and reactive power sharing in islanded microgrids. To this end, based on the average voltage observer, this paper proposes a distributed sliding mode secondary control strategy, which can adjust the average voltage of the microgrid to the reference value while realizing reactive power sharing. In this paper, first, the hierarchical control architecture for islanded mi-crogrids based on droop control is shown; next, the deficiencies of the primary control are analyzed, and the goals of the secondary control are given; after that, the average voltage observer used in secondary control is introduced; then, the distributed sliding mode secondary voltage controller is designed by selecting the sliding mode function combined with the exponential reaching law; finally, the simulation experiment is carried out to verify the performance of the proposed control strategy.