Calculating the Expansion of the 22 kV Electrical Distribution System for the Industrial Factory

This research presents a detailed study on the calculation, design, and planning for the expansion of a 22 kV, 2.75 MW power distribution system to serve a newly constructed industrial factory. The objective of this project is to provide a reliable and efficient electrical supply to meet the operational demands of the new factory while ensuring safety, cost-effectiveness, and long-term sustainability. The study comprehensively considers multiple technical and economic factors. These include the optimal routing of distribution line, the design and layout of the overhead power distribution system within the factory premises, and the installation of a new transformer at the substation. In addition, it covers the installation and replacement of key distribution system components, detailed estimation of materials and equipment costs, and an economic analysis to assess project feasibility. The findings indicate that the total construction budget for this expansion project is 1,587,395.12 USD (1 USD = 32.54 THB). The payback period has been calculated at 3 years and 2 months, demonstrating a relatively short time to recover the initial investment. The net present value (NPV) of the project is 894,930.77 USD, and the internal rate of return (IRR) is 21%, indicating a strong potential for financial viability. These results provide a reliable basis for decision-making regarding investment in the power distribution system expansion. They also reflect the project’s technical and economic feasibility, supporting strategic long-term financial planning for both the power plant and the associated industrial facility. This study can serve as a practical guideline for engineers, project managers, and investors in the energy and industrial sectors.