A life cycle cost-effectiveness assessment model for power transformer selection based on grey correlation analysis

The investment of a power transformer plays an important role in power equipment investment. Researchers have been focused on one-time cost of transformers while the future cost and benefit had been ignored. The life cycle cost (LCC) of a transformer was defined as the total cost through its whole life. Researches show that cost and effectiveness of the equipment are unity of opposites, and selecting the best investment program based on both cost and effectiveness can avoid financial losses. Factors that influence transformer´s Life Cycle Cost relate to and also constrain each other. In this study, these factors are simplified as the economic factor and efficiency factor, and the main indices are chosen in the two factors. According to the above factors and indices, a three-level index system of quantitative and qualitative factors was established. Evidential reasoning was applied to quantify the qualitative indices. However, transformer investment evaluation is full of uncertainty as it is hard to obtain accurate and useful cost effectiveness results. The cost-effectiveness evaluation model in this study used grey correlation analysis for the power transformer selection. The results from this study show that the proposed approach is effective and offers a new approach to evaluating transformer investment.