Below 35 kV, 400–10000 kVA Wind Power Combined Transformer

The DINGXIN Wind Power Combined Transformer is a purpose-built pad-mount transformer designed for wind turbine step-up and wind farm collector network applications. Covering a capacity range from 400 kVA to 10000 kVA, each unit integrates a booster transformer body, high-voltage switchgear, fuse, tap switch and auxiliary equipment into a single, factory-tested enclosure — with the HV switch and fuse placed directly inside the oil tank.

This compact integrated layout — first introduced to the wind industry in the 1990s — minimizes the footprint at each turbine pad or collector node, simplifies on-site wiring, and provides reliable medium-voltage interconnection for utility-scale wind farms. DINGXIN modernizes the design with a fully insulated cable connection and touchable plug-type arrester, removing all exposed high-voltage live parts for maximum operator safety in remote, unattended wind sites.

For multi-MW wind turbines, DINGXIN offers large-capacity units (4000–10000 kVA) with HV ratings up to 38.5 kV (35 / 36.75 / 37 / 38.5 kV) and LV ratings of 0.69 / 0.8 / 0.95 / 1.14 kV — matching the output of modern 3–15 MW wind turbine generators. These larger units feature an external radiator with conservator for enhanced heat dissipation and oil-level stability, extending transformer service life under the high and variable loads typical of wind generation.

Two structural configurations are offered:

1. Fully Insulated, No Exposed Live Parts The 12 kV / 40.5 kV side outlet uses a prefabricated cable joint combined with a touchable plug-type arrester. The entire product has zero exposed high-voltage conductors, delivering a high protection level and safe, reliable operation in harsh outdoor wind-farm environments — coastal, desert, high-altitude and cold-climate sites alike.

2. Dual-Box Independent Maintenance The fully insulated sub-box type separates the transformer and HV components into two independent enclosures. This solves oil-contamination issues and allows the HV section and transformer to be repaired separately, minimizing turbine downtime and reducing maintenance cost over the 20–30 year wind farm lifecycle.

3. Flexible Terminal & Ring-Main Wiring Both terminal (Z) and ring-main (H) wiring schemes are supported, enabling flexible collector-line design for radial, looped or hybrid wind farm topologies. The modular layout adapts to different turbine spacing and collector cable routing strategies.

4. Dual-Range Fuse Protection

• 12 kV products: plug fuse + backup protection fuse for dual-range fault-current interruption.

• 40.5 kV products: insert dry fuse for reliable high-voltage fault clearing.

This ensures robust protection against both low-level and high-level faults encountered in wind farm collector networks.

5. IP68 Sealed, Zero-Leakage Tank The oil tank is rated IP68 and each unit passes a 50 kPa / 12-hour sealing test to guarantee no oil leakage under prolonged outdoor exposure — critical for environmentally sensitive wind sites and offshore installations.

6. Advanced Manufacturing Technology DINGXIN employs robotic automation throughout the manufacturing process to ensure consistent quality and performance:

• Robotic core stacking — reduces no-load loss, no-load current and noise.

• Automatic HV winding — high-density DPE point-glue paper as interlayer insulation, improving conductivity and short-circuit withstand.

• Automatic LV foil winding — argon-protected internal welding for low resistance; F-class pre-impregnated cloth interlayer insulation for enhanced electrical and mechanical strength.

• Wrap-winding process — LV coil wound directly on the core limb, with HV and LV coils wound together for compact structure.

• Robotic tank welding — reliable, consistent weld quality.

• Robotic spray painting — uniform film thickness, strong adhesion, excellent corrosion resistance for outdoor longevity.

• External radiator with conservator (large-capacity units) — enhances heat dissipation and maintains stable oil level, extending transformer service life.

Wind Transformer Main Parameters

Service Conditions

Standards & Compliance

Energy Efficiency Levels (35 kV Class Oil-Immersed, Wind/PV/Storage Duty)

NX1 is the highest energy-efficiency level (lowest loss). Intermediate ratings (2250–4750 kVA) and large-capacity units up to 16000 kVA are available for multi-MW turbine clusters and shared collector nodes.

Model Code Description

Z (Combined Type) — G (Sharing Box) / F (Divided Box) — Design Code — Wiring: Z (Terminal) / H (Ring) — Wind Power Generation — HV Rating (kV) — LV Rating (kV) — Rated Capacity (kVA)

• Onshore Wind Farms — Step-up at individual wind turbine pad or wind farm collector node; compact footprint reduces land use and foundation cost.

• Offshore Wind Farms — IP68-sealed, corrosion-resistant units engineered for marine environments; dual-box design enables maintenance without full unit replacement.

• Wind Farm Collector Substations — Ring-main (H) wiring enables looped collector topology with redundancy; terminal (Z) wiring suits radial layouts.

• Cold-Climate Wind Sites — Operating range to −40 °C; sealed tank prevents moisture ingress in freeze-thaw cycles.

• High-Altitude Wind Farms — Rated for altitudes up to 3000 m; fully insulated design eliminates flashover risk in thin-air environments.

• Coastal / Saline Wind Sites — IP68 tank + IP45 chambers resist salt spray; no exposed HV live parts minimize corrosion-related failures.

• Desert Wind Farms — Dust and sand resistant sealed enclosure; plug-type arrester protects against dust-induced tracking.

• Wind Farm Retrofit & Repowering — Porcelain sleeve outlet type for integration with existing collector infrastructure during turbine repowering projects.

DINGXIN wind power combined transformers are engineered to project-specific requirements. The following customization options are available:

Contact DINGXIN with your wind project specification (turbine rating, collector voltage, site conditions) for a tailored quotation.

FAQ

Q1: What is a wind power combined transformer? A wind power combined transformer is a compact pad-mount unit that integrates the booster transformer body, HV switchgear, fuse, tap switch and auxiliary equipment into one enclosure. The HV switch and fuse are placed inside the oil tank, giving a small footprint ideal for wind turbine step-up at the base of each turbine or at wind farm collector nodes.

Q2: What are the two structural types available? (1) Fully insulated sub-box type — transformer and HV components in two independent boxes, allowing separate repair and preventing oil contamination. (2) Porcelain sleeve outlet box type for traditional installations with exposed bushings.

Q3: How does the fully insulated design improve wind farm safety? The fully insulated version uses a prefabricated cable joint and a touchable plug-type arrester for the side outlet. The entire product has no exposed high-voltage live parts, providing high protection and safe operation in harsh outdoor environments — coastal, desert, high-altitude and cold-climate wind sites.

Q4: What fuse protection is used? 12 kV products use a plug fuse combined with a backup protection fuse for dual-range protection. 40.5 kV products use an insert dry fuse. This ensures reliable fault-current interruption for both low and high fault levels in wind farm collector networks.

Q5: What protection level does the enclosure provide? The oil tank is rated IP68 and the HV/LV chambers are rated IP45. Each tank passes a 50 kPa / 12-hour sealing test to guarantee zero oil leakage.

Q6: Can the wind transformer support both terminal and ring-main wiring? Yes. Both terminal (Z) and ring-main (H) wiring schemes are supported, enabling flexible collector-line design for radial or looped wind farm topologies.

Q7: What environmental conditions can the unit withstand? Altitude ≤ 3000 m, ambient temperature −40 °C to +45 °C, outdoor wind speed ≤ 30 m/s, daily-average humidity ≤ 95%, monthly-average ≤ 90%. Suitable for onshore, offshore, coastal, high-altitude and cold-climate wind farms.

Q8: Which standards does the product comply with? IEEE C57.12.00, IEEE C57.12.10, IEEE C57.12.34, IEC 60076-1, IEC 60076-2, IEC 50588 and IEC 62271-202. Full type-test reports and FAT documentation are provided.