Up till now, quite a large number of highly energy-efficient transformers are already in use in rural grids. Recently, S9 series energy-efficient transformers have been successfully developed and they can compete favorably with other similar products in the international market. Also, to meet the requirement of voltage regulation for rural grids, SZ 9 series transformers with no-load voltage regulation have been developed to meet the purpose of stabilizing the secondary voltage of the transformer, and enhance the quality of power supply and safety of consumer`s electrical appliances.