An Alternative Approach for the Evaluation of Techno Economical Total Owning Cost TOC of Distribution Transformers

Abstract

A large number of distribution transformers are being currently used in the electricity distribution network in India. During purchasing them, it is not sufficient to evaluate and analyze only the purchase price of the transformer. There are no-load losses as well as load-losses in the transformer during its lifetime, which is about 30 years. As in present scenario 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 depends on total owning cost (TOC) method that consist of transformer bid price and cost of transformer losses. Similar to energy cost, greenhouse gas (GHG) emissions are also assigned a price by energy markets. Therefore this study recommended an innovative transformer cost evaluation methodology by introducing the environmental cost (EC) into the conventional TOC method. This EC is due to GHG emissions associated with supplying transformer losses. For the power system specifically for distribution system the cost of environment loss method is proposed and the results are compared to the conventional TOC, indicating the importance of incorporating environmental cost into transformer economic evaluation. Improvements in energy efficiency of electrical equipment reduce the greenhouse gas (GHG) emissions and contribute to the protection of the environment. This thesis proposes a simplified model that total owing cost of transformer. This environmental cost is coming from the cost to buy GHG emission credits because of the GHG emissions associated with supplying transformer losses throughout the transformer lifetime. It is important to include the environmental cost of transformer losses into the cost minimizing evaluation of distribution transformers. So the transformer with minimum TOC would be the most energy efficient transformer, such transformer are commercially and technically viable. Reduction in power losses in transformer further i