Our power Transformers are engineered for grid and industrial applications where consistent output voltage is critical, despite input fluctuations or varying load conditions. Available for voltage classes from 10kV to 110kV, these oil-immersed transformers feature robust on-load tap-changers (OLTC) that allow for manual, motor-driven, or automatic voltage adjustment without interrupting the power supply. Designed and manufactured in full compliance with Chinese National Standards GB1094 and GB/T6451, they deliver reliable performance, superior mechanical stability, and enhanced energy efficiency options to optimize your system's total cost of ownership.
Key Features & Advantages
• Stable Output Voltage
Equipped with reliable on-load tap-changers (OLTC) for ±4x2.5% (10kV) or ±3x2.5% (35kV) regulation range. Enables real-time voltage adjustment to maintain a stable output, ensuring power quality for sensitive loads.
• High Mechanical Robustness
The core and winding assembly is secured with a unique triple-point (top, middle, bottom) positioning system and special anti-loosening, anti-vibration measures. This design ensures structural integrity during transportation and operation, often eliminating the need for core inspection upon installation.
• Leakage-Prevention Design
The tank is constructed from high-strength steel plates. All gaskets and seals utilize advanced, long-lasting acrylate rubber compounds that resist aging, effectively preventing transformer oil leakage over the long term.
• Flexible Cooling & Configuration
Offered in self-cooled (ONAN) or fan-cooled (ONAF) variants (denoted by model code "F"). The design accommodates various connection and impedance requirements.
• Tiered Efficiency Options
Available in multiple energy efficiency tiers (Level 1, 2, 3 as per Chinese standards), allowing you to select the optimal balance between initial investment and long-term operational savings based on load profiles and economic criteria.
Specifications & Parameters
| Category | Specification / Description |
| Voltage Class | 10kV, 35kV (Up to 110kV available in series) |
| Type | Three-Phase, Oil-Immersed, Double-Winding |
| Tap Changing | On-Load Tap Changer (OLTC): ±4x2.5% (10kV), ±3x2.5% (35kV) Off-Circuit Tap Changer (OCTC): ±2x2.5% (10kV, 35kV) |
| Standards | GB1094 (Power Transformers), GB/T6451 (Technical Parameters & Requirements) |
| Core & Coil Assembly | Triple-point rigid positioning with anti-vibration design. |
| Tank & Sealing | High-quality steel plates. Acrylate rubber gaskets for long-term seal integrity. |
| Cooling Mode | ONAN (Self-Cooled) or ONAF (Fan-Cooled, denoted by "F" in model) |
Key Performance Data (Example for 35kV Series)
The table below illustrates the tiered efficiency levels for the 35kV series. Please contact us for the complete datasheet covering all voltage classes and ratings.
35kV Oil-Immersed Three-Phase On-Load Tap-Changing Power Transformer Loss Table
| Rated Capacity (kVA) | Efficiency Level 1 |
Efficiency Level 2 |
Efficiency Level 3 |
|||
| No-Load Loss (kW) | Load Loss @75°C (kW) | No-Load Loss (kW) | Load Loss @75°C (kW) | No-Load Loss (kW) | Load Loss @75°C (kW) | |
| 3150 | 1.8 | 22.2 | 2.1 | 22.2 | 2.6 | 23.5 |
| 4000 | 2.1 |
26.2 | 2.5 | 26.2 | 3.1 | 27.6 |
| 5000 | 2.6 | 30.8 | 3.0 | 30.8 | 3.7 | 32.5 |
| ... | ... | ... | ... | ... | ... | ... |
| 31500 | 12.0 | 104.4 | 14.2 | 104.4 | 17.4 | 110.2 |
Packaging, Warranty & Certifications Packaging：
The transformer is shipped fully assembled with nitrogen filling for protection. Detachable radiators, conservators, and accessories are securely crated. The main unit is mounted on a sturdy skid base suitable for roll-on/roll-off and heavy-lift transport.
Warranty：
We provide a standard 12-month warranty from the date of commissioning or 18 months from shipment, whichever comes first. This warranty covers defects in materials and workmanship under normal operation and service.
Quality Certifications：
Our manufacturing quality management system is certified to ISO 9001. Products are designed, tested, and produced in strict accordance with GB1094 and GB/T6451 standards.
Testing：
Every transformer undergoes comprehensive routine tests, including but not limited to turns ratio, winding resistance, impedance voltage, no-load & load loss measurement, and dielectric withstand tests. Type tests and special tests (e.g., temperature rise, short-circuit withstand) are conducted as required.
