Modeling and Coordination Control of Hybrid AC/DC

Abstract — Microgrid concept acts as a solution to integrate large amounts of micro generation without disrupting the operation of utility grid. Power generation from renewable energy sources like wind, solar, fuel cells, microturbines etc will give significant momentum in near future. Thus, hybrid AC/DC microgrid will be the best solution to reduce multiple reverse conversions (dc-ac-dc or ac-dc-ac) in an individual ac or dc grid. The proposed hybrid grid consists of both AC and DC networks connected to distribution generation through the multi-bidirectional converters. AC sources and loads are connected to AC network whereas DC sources and loads are tied to the DC network. Energy storage systems can be connected to dc or ac links. This microgrid can operate in a grid-tied or isolated mode. The coordination control schemes are proposed for smooth power transfer between AC and DC links during various supply and demand conditions. This paper presents a simulation of small hybrid microgrid and its modeling in the MATLAB/SIMULINK environment. Keywords—Coordination control operation, grid control, grid operation, hybrid microgrid, isolated mode, PV System, wind power generation. I