Economic evaluation of transformer selection in electrical power systems (original) (raw)

Economic Evaluation of Transformer Selection in Distribution Systems

This paper presents an approach to determine the total owning cost (TOC) of transformers. Different assumptions are introduced by discounting the transformer cost and/or the losses cost, using either A and B loss coefficients or the idea of annuity factor. Moreover, the paper presents a comparative study between different cases under different presumptions to evaluate the transformer's TOC. The obtained results confirm that the proposed approach equips the decision-maker with valuable and trustable criteria to select the proper transformer(s) based on the proposed practical cost criteria. The presumptions of the proposed cost criteria influence economic evaluation. The TOC of the transformer is also illustrated. Finally, the proposed approach cost criteria were illustrated through a numerical example. The obtained results have been summarized and discussed.

Economic Criteria in Competition for Deliveries of Power Transformers

Latvian Journal of Physics and Technical Sciences, 2009

In the article, economic estimation is given for the measures on purchase of new power transformers and replacement of the existing ones for the Latvian power system (Latvenergo). The optimal choice for the purchases and deliveries of new power transformers is considered as a task of choosing among suppliers on a competitive basis (through tenders). As the objective function for the estimation, the total annual discounted costs for the user of a transformer during its service life are taken. A simplified estimation model is proposed, based on which the calculations of tenders have been done.

Economical analysis for efficient transformers projects

2010

This paper presents results for the economical analysis of efficient monophase transformers when used instead of standard transformers made at the High Voltage Laboratory if Federal University of Itajubá (LAT-EFEI). The analysis was made using capitalization rules based into two wages cycles, as recommended by Brazilian Electrical Energy Agency-ANEEL. In addition, it is also discussed, briefly, a comparison made with the traditional method using the present value of transformer losses costs. Finally, authors propose a methodology to study the application of efficient transformers to replace the ones standardized by Brazilian normative association, ABNT.

Decision support system for evaluating transformer investments in the industrial sector

This paper presents a decision support system (DSS) for evaluating transformer investments in the industrial sector. The DSS evaluates transformer bids based on the total owning cost (TOC). Among all transformer offers, the most cost-effective and energy-efficient transformer is the one with the lowest TOC. The DSS compares the selected offer with the other competing offers. Moreover, the proposed DSS deals with the uncertainty of the values in the TOC formula by performing a sensitivity analysis.

Distribution transformer cost evaluation methodology incorporating environmental cost

As system investment and energy costs continue to increase, electric utilities are increasingly interested in installing energy-efficient transformers at their distribution networks. The cost evaluation of transformers is based on total owning cost (TOC) method that includes transformer purchasing price and cost of transformer losses. Similar to energy cost, greenhouse gas (GHG) emissions are also assigned a price by energy markets. That is why this study proposes an innovative distribution transformer cost evaluation methodology (DTCEM) by introducing the environmental cost (EC) into the conventional TOC method. This EC is due to GHG emissions associated with supplying transformer losses. The proposed method is applied for economic evaluation of distribution transformers for the Hellenic power system and the results are compared to the conventional TOC, indicating the importance of incorporating EC into transformer economic evaluation. A sensitivity analysis is carried out, investigating the impact of various parameters involved in the proposed DTCEM.

Distribution transformers represent a significant cost to electric utilities, both as a capital

2004

Distribution transformers represent a significant cost to electric utilities, both as a capital investment and as an ongoing operating expense. A survey of seven 2003 FERC Form 1 filings shows that distribution transformers can account for approximately 9 to 20% of total distribution capital spending in a year. Productivity tools that help to minimize transformer total owning costs and increase overall asset utilization can make a significant impact on a distribution utility’s bottom line. The Distribution Systems Testing, Application, and Research (DSTAR) utility consortium commissioned the development of the Transformer Owning Cost Software (TOCS) tool for analyzing and comparing the total owning cost of distribution transformers.

Economic Benefit Analysis of 220 kV Energy-saving Power Transformer

Energy and Power Engineering, 2013

Power transformer serves as one of the most widely used electrical equipments in power grid. During the operation, terrible losses are produced. With the development of loss reduction technology of power transformers, in order to save energy saving and reduce emissions, the old power transformer should be replaced. The paper summarizes the main method to reduce the losses of power transformers and brings up the improved Total Owning Cost (TOC) algorithm, which applies to 220 kV power transformers' comprehensive benefit analysis. Using the improved Total Owning Cost (TOC) algorithm, based on today 220 kV energy-saving power transformer manufacturing level, the economic benefits of new energy-saving power transformer and the return period of investment are analyzed. Finally, combined with energy-saving effect, the appropriate replacement proposal of 220 kV power transformers has been given.