The transformer is built into the wind generator nacelle, which can realize the local voltage boost transmission, reduce the occupation of land by the foundation, reduce the cross-section of the transmission cable, reduce the load of the tower pole, reduce the transmission cable line loss, improve the overall transmission reliability and economy, save the investment cost; It can resist the negative influence of environment, vibration, temperature, load and other aspects on transformer operation, and run safely and reliably for a long time. The product can meet the energy efficiency level of the latest EU standard in July 2021; H class insulation material, higher heat resistance temperature, product safety margin is larger; It has passed the tests of CESI in Italy and LCOE in Spain. The series design has been completed, covering 3.4MW, 4.5MW, 5MW, 6MW, 7MW and other mainstream wind power models, which can completely replace imports.