The 20kV series fully sealed distribution transformer utilizes the finned panels of its corrugated tank as heat dissipation components, which expand and contract with the fluctuation of transformer oil volume. This design isolates the internal environment from the atmosphere, effectively preventing oil degradation, insulation moisture absorption, and aging, thereby significantly enhancing operational reliability. The tank welds are full, smooth, even, and uniform in thickness, ensuring complete leak-proof performance.

The core is constructed with 0.23mm high-permeability laser-scratched silicon steel sheets and features a stepped five-level gap structure, which helps reduce no-load losses and no-load current, making it a new generation of environmentally friendly product. Anti-loosening nuts are used for core tightening and clamping.

The high-voltage winding adopts a multi-layer layered structure with adhesive-coated paper for interlayer insulation, enhancing the mechanical strength of the winding. The low-voltage winding is either layered or of a new spiral type, also using adhesive-coated paper for interlayer insulation. The low-voltage winding is equipped with formed end rings, providing gapless full support and excellent mechanical strength.