An Unequal Power Sharing Strategy for Capacitive- and Inductive-Coupling Inverters in Microgrid

Flexible reactive power condition is vital for a microgrid (MG) system. The power conditioning character of the capacitive-coupling inverter (CCI) based DG unit distinguishes it from the inductive-coupling inverter (ICI) based DG unit. Previous studies indicate that CCI is more cost-effective in reactive power conditioning and reactive power regulation ability is enhanced. Thus, to improve the flexibility of reactive power condition for the MG system, a brand-new MG frame with hybrid connected ICIs and CCIs are proposed. Besides, considering the CCI can word under a lower DC-link voltage, to reduce the total inverter’s capacity of the proposed system and decrease the loss, in this paper, an unequal power-sharing method is investigated. Power-sharing schemes with different cases are studied, and a neural network-based sharing ratio computation method is proposed. Simulation and experiment results verified the effectiveness of the proposed method.