Application of Polynomial Regression Analysis in Evaluating the Techno-Economic Performance of DSPV Transformers

Abstract

To this extent, the delineation of techno-economic evaluations for transformers becomes more intricate through a lens of Distributed Solar Photovoltaic (DSPV) market in South Africa. Essentially, the transformer price and loss evaluation techniques should be tailored for calculating the Total Ownership Cost (TOC) of transformers facilitating decentralized energy systems. In South Africa, the traditional coal power generation and renewables operate concurrently under liberalized energy markets but have distinct operational requirements and therefore have distinct methods for evaluating their generating states, service loss costs and TOC. As a result, their techno-economic evaluations should be different. In this work, new formulae have been developed to contemplate on a comprehensive technique for calculating the transformer prices and losses necessitated to estimate the cost of service losses and TOC for DSPV transformers. These formulae are based on experimental studies undertaken on a fleet of DSPV transformers ranging from 1.25 to 250MVA. In order to substantiate these new formulae, 4 case studies have been presented. The calculated losses and associated cost results against the pragmatic values from the case studies yield an error of estimation of less than 1% and 2% respectively in all cases. Further, these results are used to calculate the cost of losses and TOC using a methodology that has been proposed in previous work exclusively for power producers who are proprietors of DSPV generation systems.