A planning framework for AC-DC bilayer microgrids

Abstract

This paper proposes a novel stochastic planning framework for bilayer microgrids (BμGs), which facilitates the integration of different types (AC and DC) of loads and distributed generations (DGs). In contrast to the conventional μG configurations that adopt single layer, the bilayer configuration has an AC layer in addition to a DC layer, where all the AC/DC loads and DGs are connected directly to the corresponding AC/DC layer. The interconnection between the AC and DC layers is achieved through one or more interlinking converters (ICs). Depending on the types, locations, and specifications of the μG loads and DGs, the planning framework allows each node to be a universal node that can include two buses (AC and DC) or a single bus (AC or DC). The network wiring can also be universal (AC, DC, or both) to facilitate the connection between the system nodes. The framework determines the optimal BμG configuration that minimizes the system total costs by providing the following decisions: the AC-layer connection; the DC-layer connection; and the number, locations and sizes of the ICs. Two case studies have been implemented and solved using different μG configurations to demonstrate the effectiveness of the proposed framework and the benefits of the BμG.