DESIGN AND OPERATION STRATEGY FOR A GRID-CONNECTED MICRO-GRID SYSTEM

ABSTRACT

The economic growth of any country is hinged on reliable and efficient power supply. Many developing countries have not attained sufficiency in energy generation. Hence, there is a need to strategize to meet the ever-rising demand for energy. The micro-grid system can provide a way of escape from this problem as it harnesses the strengths and weaknesses of different energy sources to attain stability in energy provision. The overall aim of this research is the design and operation strategy for a grid-connected micro-grid system for reliable and cost-effective energy utilisation. The designed micro-grid, which is made up of three power sources (solar photovoltaic, grid and fossil-fuelled generator), utilises a microcontroller-based system to reliably organise the flow of the hybrid power mix from energy sources and battery bank in a cost-effective manner. The microcontroller was programmed to monitor the DC voltage levels of the battery to decide which of the sources powers the load. Results showed that the developed operation strategy proffers appreciable techno-economic benefits especially in areas of energy savings and power supply availability. The developed strategy yielded a grid energy savings of 66.7% and a reliability improvement of 6.5% compared to the conventional strategy. The high energy saving, as well as improved power supply reliability of developed strategy, has become increasingly necessary especially in the face of exorbitant power supply rates of the various electric power distribution companies in Nigeria.