Passive-Regulated DC Microgrid for Rural Electrification: An Assessment from a Design for Localisation Approach

Low voltage DC microgrids can provide reliable, safe and efficient energy distribution for photovoltaic-battery systems. When used in a rural electrification context, these systems can be implemented either by using commercial off-the-shelf DC-DC converters or, most commonly, by using custom application-specific converters. These components do not usually allow local repair and maintenance, causing issues when failures occur. This paper presents a study case for the development of DC-DC power converters based on the Design for Localisation approach, that aims to design a product for local manufacture, use, repair and end-of-life processing, whilst considering the production process availability and the context of the local geographic area. In a rural electrification context, the Design for Localisation methodology makes it possible to use local skills and capabilities, contributing to the reduction of costs and time to repair, increased reliability and overall sustainable development of the community. The case study is based on a 24 V passive-regulated DC microgrid operating in the Brazilian Amazon, which currently operates using commercial off-the-shelf equipment and was developed as an alternative for remote electrification to reduce demand for household-scale diesel generators, commonly used in the community. The 3 Design for Localisation rules are applied to design a DC-DC power converter to substitute the commercial battery charge controllers that are used to control the PV generation and to form the microgrid. The proposed design is evaluated against the Design for Localisation criteria to show the feasibility of the design and establish the next steps required for implementation.