Study And Evaluation Of Distribution Schemes In Which 20kV Is Used Based On AHP/DEA

In this paper, analysis of transformer's capacity and power supply capability of lines where 20kV is used is made, and the composition of the economy of distribution schemes is analysed, based on which an economic model is established.The optimization variables of the model are transformer's capacity and line's section, and the aim is to minimize the cost used in construction and operation of power gride per year. A system of evaluation indicators is established using AHP,also, improvements of the DEA evaluation model with AHP preference cones are made.In the improved model, the concept of "pseudo-judgment matrix" is proposed to solve the problem of making the preference cone matrix if the number of indicators is more than 9,and a relaxation factor is introdused to solve the problem how to make the combination of subjective and objective reasonable in the evaluation. The case in the paper proves the economic model, and the improved evaluation model can give such weights distribution that is not only objective but meets the will of decision makers as well, so that the sequence of distribution schemes can be given and the best scheme can be chosen.