Electrical energy is one of the most important resources of human society. Each year, a considerable amount of the produced electrical energygoes to waste during transportation from power plants to the customers. Losses, are defined as a portion of the electric energywhich does not have the ability to perform beneficial work. Numerous factors contribute to losses in distribution networks which are generally divided into two categories:losses due to technical factors and losses resulting from the non-technical and management factors. In this paper, through collecting and analyzing the necessary data from registers installed in distribution transformers of city of Chardavol, and also using the existing standard relationships between Loss Factors, a suitable model is presented in order to estimate the losses in terms of load factor for the distribution transformers of the abovementioned city. As have been mentioned in the article, the third model is the most appropriate one for the air distribution substations in the city of Chardavol. Appropriate models for the rest of the distribution substations can be obtained using the presented method and the data provided by registers.
