Oil immersed transformers are voltage conversion devices that use oil to keep the transformer cool. This type of transformer structure is mounted in a welded steel oil tank filled with oil. Due to the liquid’s inflammability, oil-filled transformers are mostly used in outdoor installations. Oil-type transformers can be put on the ground, on a pad, or on a pole. They function well in various environments, including transmission and distribution lines, renewable energy generation, and small businesses. S-35kV series oil immersed transformer produced by the company is suitable for three-phase AC 50 / 60Hz, rated voltage 35kV distribution grid, and plays an important role in high-voltage transmission and low-voltage power supply.