Underground transformers are a new generation of distribution transformers developed to meet the needs of urban construction. It is suitable for installation on the ground of streets, squares, highways, airports, tunnels, parking lots, tourist attractions, etc., in basements or cellars under lawns and flower beds. The appearance and function of underground transformers are similar to the column mounted transformers or pedestal mounted transformers (combination transformers) that we see in our daily lives, but it has a higher level of technology and operates more safely and reliably.