Abstract: The energy efficiency upgrade of energy saving distribution transformer is an important measure to implement the basic national policy of energy saving and emission reduction in China and promote the technological progress of transformer industry.The manufacturing technology of transformer core and its superposition structure are directly related to the noload loss, noload current and noise.By comparing the main indexes of four kinds of transformer core manufacturing technology,the advantages and disadvantages of them were analyzed, and different design methods or magnetic materials or new materials were put forward to realize energy saving and consumption reduction of distribution transformer, reaching the standard of energy efficiency grade, which can be popularized and applied vigorously.

Key words: energy saving distribution transformer, iron core, manufacturing technology, comparative , analysis