220kV Class Oil-Immersed Power Transformer

Overview

The 220kV class oil-immersed power transformer is used for grid hub substations, large power plants and renewable energy bases for source connection and step-up transmission. Complying with GB 1094, GB/T 6451 and IEC 60076, it covers 6.3 MVA to 240 MVA with ONAN/ONAF/OFAF multi-stage cooling to meet long-distance transmission and high-reliability requirements.

Features

• Three-phase five-limb or three-limb core construction, stacked from high-permeability grain-oriented silicon steel with mitred joints for low no-load loss;
• Windings in interleaved or inner-shield continuous disc type for even impulse voltage distribution and strong short-circuit withstand;
• Bell-type or tank-type oil tank with capsule conservator, fully isolating oil from air;
• Selectable ONAN/ONAF/OFAF cooling, automatically switched by load and temperature rise;
• Optional on-load tap changer (OLTC) and online monitoring (DGA, partial discharge, fiber-optic temperature sensing).

Selection Advice

Size according to substation voltage level, system impedance and short-circuit capacity. For long-distance transmission, low-loss models are recommended to reduce lifecycle cost.

Applications

220kV hub substations, step-up stations for large thermal/hydro/wind and PV bases, regional grid interconnection projects.