CE Certified 55kV 2x27.5kV 10MVA 10000KVA Ultra-low Energy Auto Transformer
- Voltage Rating: 55kV / 2x27.5kV
- Rated Capacity: 10,000 KVA (10MVA)
- Application: High-Speed Rail & Electric Traction
Flagship Procurement Catalog
Featured Traction & Distribution Transformers
Explore our ISO 9001:2015 and CE/BIS certified traction transformers, auto-transformers, and custom voltage conversion systems optimized for global railway infrastructure and industrial power grids.
Customizable 300W Toroidal Universal Isolation Auto Transformers
- Multi-Voltage Output: 12V to 38V Range
- Core Type: High-Permeability Toroidal
- Feature: Ultra-Quiet & Low Stray Magnetic Field
Wholesale EF25 Step Down Constant Current Ferrite Core Transformer
- Core Design: Premium EF25 Ferrite
- Topology: High-Frequency Constant Current
- Use Case: Auxiliary Railway Electronics & LED Drives
Square 60Hz 220V Heavy-Duty Auto Distribution Transformers
- Operating Frequency: 50Hz / 60Hz Dual
- Primary Voltage: 220V Standard
- Enclosure: Compact Vibration-Resistant Housing
Modular Three-Phase YBW Compact Transformer Substation IP44
- Protection Rating: Outdoor Weatherproof IP44
- Integration: HV Switchgear + Transformer + LV Panel
- Efficiency: High-Tension Traction Substation Standard
10KVA 220V to 380V 3 Phase Toroidal Winding Step Up/Down Transformer
- Phase Configuration: 3-Phase Step Up / Step Down
- Winding Material: High-Grade Electrolytic Conductor
- Frequency Range: 50/60Hz Universal Grid Compliance
Industrial Grade Replacement Cooling Fan Transformer 6SL3352 Series
- Compatibility: Industrial Drive & Substation Cooling
- Thermal Rating: Class H High-Temperature Insulation
- Reliability: Continuous 24/7 Duty Cycle Approved
SBK Series 3-Phase Isolation & Auto Transformer 10KVA to 150KVA
- Capacity Range: 10KVA, 20KVA, 50KVA up to 150KVA
- Voltage Taps: 415V / 380V / 240V / 220V / 110V
- Winding Options: Pure Copper / High-Purity Aluminum
Industry Technical Whitepaper
Engineering Principles of Modern Railway Traction Transformers
Traction transformers represent the critical energetic bridge between high-voltage utility grids and rolling stock traction systems. Operating under extreme mechanical vibrations, rapid load fluctuations, and severe electrical harmonics, Chinese OEMs lead global manufacturing with unmatched reliability and cost efficiency.
25 MVA
Max Single-Unit Capacity
66 KV
Voltage Class Execution
15+ Yrs
Global OEM Export Leadership
99.85%
Operational Grid Efficiency
1. The Critical Role of 2x27.5kV Autotransformer (AT) Systems
In modern high-speed electric railways (HSR) operating at speeds exceeding 250 km/h, single-phase 25kV feeding systems encounter significant voltage drops and electromagnetic interference with neighboring telecommunication networks. Leading Chinese wholesale exporters specialize in manufacturing Advanced 55kV / 2x27.5kV Autotransformers (AT), such as the CE-certified 10MVA auto-transformer series.
By stepping down the feeder line voltage from 55kV to dual 27.5kV circuits relative to the traction rail (neutral), current return path loss is drastically minimized. This allows traction substations to be spaced twice as far apart (up to 40–50 km) compared to conventional direct supply systems, delivering immense capital expenditure savings for international railway EPC projects.
Technical Specification Matrix: Traction Transformer Topologies
Procurement engineers must evaluate dielectric media and structural topologies based on installation environments—whether mounted onboard rolling stock or stationed inside trackside substations.
| Technical Parameter | Oil-Immersed Traction Transformer | Cast-Resin Dry-Type Transformer | Toroidal Isolation Autotransformer |
|---|---|---|---|
| Primary Standards | IEC 60310 / EN 50329 / IS 1180 | IEC 60076-11 / IEEE C57.12.91 | IEC 61558-2-13 / CE Compliance |
| Cooling System | ONAN / ONAF / OFAF / ODAF | AN / AF (Natural/Forced Air) | AN Convection |
| Thermal Class | Class A (105°C) / Class K (Synthetic Ester) | Class H (180°C) / Class C (220°C) | Class B (130°C) / Class F (155°C) |
| Harmonic Tolerance | High (Damped by liquid dielectric) | Very High (K-Factor 13 / 20 rated) | Moderate (Auxiliary circuits) |
| Short-Circuit Resistance | Extreme Dynamic Withstand Capacity | High Structural Stiffness | Self-Limiting Impedance Option |
| Best Application | Trackside Substation & Heavy Freight HSR | Subway Stations & Urban LRT Systems | Locomotive Control Panels & Drives |
Harmonic Mitigation Engineering
Railway traction drives employ IGBT traction converters that feed non-linear currents back into the transformer windings. Our units feature multi-shielded electrostatic screens and optimized stray flux channels to prevent local hotspot overheating.
Extreme Surge & Dynamic Duty
Train acceleration creates instantaneous overloads reaching 150% to 200% of nominal rating for short intervals. Windings are locked under high axial pre-compression forces to withstand frequent electrodynamic short-circuit forces.
Eco-Friendly Synthetic Esters
Moving beyond traditional mineral oil, our high-capacity traction transformers can be engineered for bio-degradable synthetic ester fluid (K-class, fire point >300°C), eliminating fire hazards in subterranean metro tunnels.
Manufacturing Excellence
State-of-the-Art Production & Quality Control
As a premier Chinese exporter backed by over 15 years of industrial power engineering, our production facilities integrate fully automated CNC winding machinery, vacuum pressure impregnation (VPI) chambers, and rigorous in-house impulse voltage testing laboratories.
Every transformer batch undergoes comprehensive routine, type, and special testing according to IS 1180 Part 1: 2014 and IEC 60310 guidelines—ensuring 100% compliance prior to international export to North America, Europe, Southeast Asia, and the Middle East.
E-E-A-T Quality Assurance
Full Lifecycle Engineering & Testing Rigor
Rooted in strict quality management systems (ISO 9001:2015), our engineering team conducts rigorous core-loss optimization using laser-cut grain-oriented silicon steel (CRGO). This guarantees ultra-low no-load losses and extended operating lifespan under heavy duty cycles.
- Dielectric Strength Testing: Automated oil breakdown testing up to 80kV.
- Dissolved Gas Analysis (DGA): Real-time monitoring during full-load burn-in tests.
- Short-Circuit Withstand Capability: Validated by independent third-party laboratories.
Strategic Procurement Insights
Key Sourcing Trends Shaping 2026-2035 Railway Sourcing
Global decarbonization, high-speed rail expansions, and smart grid integrations are rapidly redefining global procurement requirements for traction transformers and distribution infrastructure.
1. Modular Substation Integration (YBW Concept)
Global buyers are shifting away from on-site constructed brick-and-mortar substations towards pre-fabricated, factory-tested Compact Transformer Substations (YBW Models). Integrating MV switchgear, high-efficiency autotransformers, and low-voltage distribution panels in a single IP44 enclosure reduces installation time by over 70%.
2. IoT-Enabled Predictive Health Monitoring
Next-generation traction transformers exported from China feature built-in Fiber-Optic Temperature Sensors (FOTS) and online Dissolved Gas Analysis (DGA) transducers. This enables railway maintenance personnel to monitor hot-spot winding temperatures in real-time and prevent catastrophic insulation breakdown.
3. Ultra-Low Loss Standards & EU Ecodesign Compliance
Energy efficiency regulations worldwide mandate lower no-load ($P_0$) and load ($P_k$) losses. China wholesale manufacturers utilize amorphous alloy cores and 0.18mm/0.20mm high-permeability domain-refined CRGO steel sheets to exceed EU Tier 2 and IS 1180 Level 3 efficiency criteria.
Technical Knowledge Base
Procurement FAQ for Railway Engineers & Global Wholesale Buyers
Direct answers to crucial technical, quality assurance, and international shipping queries encountered during traction transformer sourcing.
Q1: What are the primary differences between ONAN, ONAF, and OFAF cooling in traction transformers?
ONAN (Oil Natural Air Natural) uses natural oil convection and air circulation for cooling, ideal for lower KVA ratings or continuous baseline duty. ONAF (Oil Natural Air Forced) adds external cooling fans to boost heat dissipation during peak traffic hours. OFAF (Oil Forced Air Forced) utilizes internal pumps to forcefully circulate insulating oil through external radiator banks, required for high-capacity 10MVA–25MVA traction substations operating under continuous heavy loads.
Q2: How do China manufacturers ensure transformer compliance with IEC 60310 international railway standards?
Compliance is verified through strict multi-stage testing. Routine tests include winding resistance measurement, voltage ratio verification, phase displacement checks, short-circuit impedance tests, and separate-source AC withstand voltage tests. Type tests validate lightning impulse withstand voltage (BIL) up to 250kV+ and temperature rise limits (65°C for oil, 100°C for windings) under simulated maximum train frequency load profiles.
Q3: Can your factory custom-design step-up or step-down autotransformers for non-standard grid voltages?
Yes. Our engineering team customizes multi-tap primary and secondary winding configurations (e.g., 220V/380V 3-phase, 415V/240V dual tap, or 55kV/2x27.5kV traction taps) across both toroidal and rectangular E-core geometries, accommodating local frequency requirements (50Hz or 60Hz) with full custom OEM labeling.
Q4: How are non-linear harmonic loads managed to prevent transformer failure?
Traction converters introduce high 3rd, 5th, 7th, and 11th harmonic currents. Our transformers incorporate K-factor optimized windings, transposed copper conductors (CTC) to minimize eddy current losses, and specialized magnetic core step-lap joints that reduce localized stray field heating.
Q5: What export packaging and moisture prevention measures are utilized for overseas ocean freight?
For liquid-immersed transformers, tanks are either shipped nitrogen-filled under positive pressure with continuous monitoring gauges or filled with degassed dielectric fluid. Dry-type and toroidal units are sealed in vacuum-wrapped moisture barrier bags and packed inside heavy-duty IP55 wooden crates with internal shock sensors.