An Efficient Planning Algorithm for Hybrid Remote Microgrids

This paper presents an efficient planning algorithm for microgrids in remote isolated communities. Different from the existing research that assumes a specific microgrid topology, we propose a planning algorithm that jointly specifies the optimal grid topology, namely AC, DC, or hybrid AC/DC, along with the optimal locations and sizes of distributed energy resources, energy storage systems, and AC-DC converters. The planning objective is to ensure reliable power flow with minimum deployment and operational costs. The planning problem is formulated as a mixed integer nonlinear program, and given the complexity of the problem, the proposed algorithm implements a two-stage framework that results in an efficient planning solution. The first stage deals with the specification of the microgrid topology, and allocation and sizing of all the equipment following a heuristic optimization approach. Upon deciding the microgrid topology and equipment installation in the first stage, the second stage of the planning algorithm ensures smooth and reliable operation for the proposed topology over all possible operation scenarios. This is achieved with minimal operational costs by considering the optimal nonlinear scheduling problem for the installed equipment. Test cases are presented to investigate the performance of the proposed planning algorithm at different fuel transportation cost scenarios.