As an indispensable key equipment in the power system, the oil-immersed transformer uses insulating oil as a cooling and insulating medium, and realizes the voltage conversion and transmission of electric energy through the principle of electromagnetic induction. It is widely used in multiple power links such as power generation, transmission, and distribution, as well as various scenarios such as industrial, commercial, and residential electricity. It can efficiently and reliably convert electric energy of different voltage levels to ensure the stable operation of the power system and the safety and reliability of power supply. The S13 series three-phase three-dimensional triangle wound core transformer is based on the S11 three-phase plane-arranged wound core transformer, and the arrangement of the core is more reasonably combined in a three-dimensional triangle. This arrangement makes the three-phase core magnetic circuit completely symmetrical, greatly reduces the magnetic resistance, and significantly reduces the excitation current and no-load loss. It has become a new product of high-efficiency, energy-saving, material-saving, low-cost, and high-performance wound core transformer with lower operating noise and more compact structure. • The use of new magnetic conductive materials and optimized winding structure reduces no-load loss and load loss, with significant energy-saving effects, effectively reducing users' long-term operating costs. • The fully sealed structure design, combined with high-quality insulating oil and high-insulation winding materials, has good insulation performance and moisture-proof and dust-proof capabilities, effectively preventing internal components from aging and failure. Equipped with complete protection devices, such as gas protection and temperature protection, it can monitor and handle abnormal situations in a timely manner to ensure safe and stable operation of the transformer. • Reasonable oil circuit design and heat sink layout can control the transformer temperature within a reasonable range even under high-load operation, ensuring long-term stable operation of the equipment. • The transformer has high mechanical strength and stable electrical performance. Under normal use and maintenance conditions, the service life can reach 20-30 years, reducing the frequency of equipment replacement and maintenance costs. • Altitude: not more than 1000m; • If the altitude exceeds 1000m, or the ambient temperature is higher than 40°C , appropriate quota adjustments should be made according to GB6450-1986 standard and relevant regulations. • Installation place: a place without fire, explosion hazard, conductive dust, chemical corrosive gas and severe vibration. S13 Series Three-Phase Double-Winding No-Load Tap-Changing Distribution Transformer