35kV series power transformers are more advanced in design, and have been greatly improved and improved in material, structure and process. The high and low pressure clamps are tightened with steel pull belts or upper and side beams to form a strong frame structure, which enhances the clamping force of the iron core and the ability to withstand transportation impact. Strong short-circuit resistance, beautiful appearance, reliable operation, low loss, low noise, to the advanced level of similar foreign products. The SZ13-20000/35 transformer prototype produced by the company passed the burst short circuit test conducted by the National transformer testing center at one time, and the longitudinal oil channel of the high and low voltage coil is conducive to heat dissipation, which can greatly reduce the temperature difference of copper oil and the most hot spot temperature rise inside the coil.