Technical and Economic Feasibility of Using Dry Transformers to Feed Large Concentrated Loads of Urban Facilities

The emergence of large concentrated loads in urban facilities requires new technical solutions for their power supply. 10–20 kV transformer substation of large power with dry type insulation instead oil type insulation more often use in modern Latvian and other cities. The mathematical model-based comparison these transformer types and choosing of the best option on purchase and operation of dry or oil transformers are created. The value of total annual discounted costs for transformer whole life cycle is proposed for reasonable selection of transformer type.