Import 330kv-220kv Power Transformer — Buy in Bulk from Supplier in China

Yugong Machinery Co., Ltd. manufactures 330kV oil-immersed power transformers with rated capacity up to 360MVA, designed for bulk electricity transmission and grid-level voltage step-down applications. The core assembly uses grain-oriented cold-rolled silicon steel with chamfered, five-step step-lapped joints to reduce no-load loss and acoustic noise below GB limits. Magnetic and copper shields line the tank interior, with structural parts in high-flux zones treated to cut stray loss and eliminate local overheating. The winding conductors operate at reduced current density, supported by calculated cooling paths that hold winding temperature rise and top-oil temperature rise more than 5 K below national standard limits.

All insulation components subject to short-circuit mechanical stress, such as winding spacers, are fabricated from T4 densified pressboard to resist shrinkage. Vertical winding machines with tensioning devices tighten the coils, and the complete active assembly undergoes two-stage drying: individual windings first, then the assembled phase block, followed by vapor-phase drying (VPD) after core-and-coil assembly. This triple-drying protocol drives moisture content to very low levels and prevents in-service shrinkage. High-voltage bushings are set in concentric turrets, and all leads are crimped, metallised and rounded to suppress corona and partial discharge.

The finished units are built to Chinese national standards GB1094.1~2-1996, GB1094.3-2003 and GB1094.5-2003, aligned with IEC 76. Cooling is natural oil circulation with forced air (ONAF), maintaining 70 % of nameplate rating if fans fail. The tank shells are stress-relieved and shot-blasted to prevent oil leakage and ensure clean exterior finish. These transformers suit regional utilities, heavy industrial substations and large infrastructure projects that need reliable 330 kV class power conversion with verified short-circuit withstand and low partial discharge.

Yugong Machinery Co., Ltd. is located at No.1288 Luban South Road, Yugong Industries, Tengzhou, Shandong Province, China, postal code 277500. The company is classified as an imported-tier supplier with a harbor trust tier, and it maintains a 0.00 % response rate with no recorded average response hours, which buyers should note when planning communication and follow-up timelines. Its product portfolio centres on large oil-immersed power transformers for high-voltage transmission networks, drawing on domestic Chinese standards and international IEC alignment.

The listing does not disclose factory floor space, annual output, workforce size, revenue, client references, or specific export licences, so any such figures would need to be requested directly from the supplier. The description does emphasise in-house winding, drying and VPD capabilities, suggesting vertical integration in core manufacturing processes rather than pure assembly. Buyers evaluating this supplier should verify its ISO or equivalent quality-system certification, track record with 330 kV grid projects, and ability to provide factory acceptance test (FAT) protocols before committing to an order.