Investigation of distribution transformer selection process based on micro-load profile modeling and classification

Distribution loads according to power demand value can be classified in many kinds that be need in various studies. Load profile is one of the factors that effect on transformer as demand suppling equipment in distribution system. Loads with same maximum power value base on profile changing, make difference residual life of transformers. In this paper have been proposed a new classification which defined micro-loads and by using proposed modeling of each types of introduced loads can generate profiles for residential, agricultural and industrial load types. Investigation of transformer behavior according to micro-load classification have been presented through three steps as proposed selection process method of transformer rating. Loss of life index have been determined for all load types and according to results the loads effects on transformer dynamic operation time and hotspot temperature have been calculated with considering of their classification. Results have realized different between load types on transformer hot spot value and loss of life and as results the utilization factor ratio.