S11‑series oil‑immersed power transformers comply with IEC 60076 standards, serving as a robust and proven solution for substation and renewable‑energy projects worldwide. Widely deployed across Southeast Asia, Africa, the Middle East and Latin America. Designed with conservator‑tank structure, OLTC (on‑load tap changer) is available as an optional configuration. Optimized internal structure enhances mechanical strength and reduces partial discharge, extending service life under heavy‑load cycling conditions. Built with high‑grade silicon‑steel core and pure‑copper windings, ONAN cooling supports long‑term continuous operation. Standard primary voltages cover 35 kV‑110 kV. Secondary voltages configurable per project demand. Capacity ranges cater to utility sub‑transmission applications for power plants, industrial parks and grid‑connection projects. We support flexible customization to match local grid requirements. Customizable items include special voltage classes, non‑standard capacity, 50 Hz / 60 Hz frequency, vector group, impedance value and tap‑changer schemes. Suitable for grid reconstruction, renewable energy integration and large‑scale industrial power supply projects. Every unit undergoes complete factory testing prior to shipment. Please send us your technical specifications for a formal quotation.