An Optimal Neighborhood Energy Sharing Scheme Applied to Islanded DC Microgrids for Cooperative Rural Electrification

Abstract

Remote rural regions without electricity access suffer from energy poverty and reduced opportunities for the population. Microgrid architectures with optimal planning, design, and operation strategies are essential to meet rural inhabitants’ energy demands. DC microgrids based on photovoltaic panels and batteries are used for remote rural electrification. Centralized islanded systems have shortcomings, i.e., high distribution losses, less efficiency, and are comparatively more expensive than distributed microgrids. The distributed systems comprise independent household prosumers that may work independently or integrated. In this paper, the optimal power dispatch and power-sharing among spatially distributed nanogrids are performed to minimize distribution losses and maximize power electronic conversion efficiency in a typical islanded DC microgrid (IDCMG) for rural electrification. A branch flow model is proposed for modeling the power system with DC-DC converters. The optimal power flow is performed by relaxing the original non-convex constraints using second-order conic programming and is implemented on the modified IEEE-14 bus DC system. This generic framework can be used for optimal energy management in islanded microgrids using the regional solar irradiance information, climate situations, and energy requirements.

Keywords

• Branch flow model
• DC microgrids
• optimal power flow
• optimization
• peer-to-peer sharing
• rural electrification