Product Description
The S11-M series fully sealed, oil-immersed, three-phase distribution transformers manufactured by Yueqing JASCO Electric are designed for 35kV power grids and are widely used in 35kV substations, mines, industrial facilities, and medium-voltage infrastructure projects worldwide.
Manufactured using advanced equipment and high-quality grain-oriented silicon steel sheets, the S11-M series features a "step-lap" core stacking process to ensure low losses, low exciting current, and minimal operating noise.
The high-voltage windings utilize a robust cylindrical structure, while the low-voltage windings employ either a cylindrical or foil design. An optimized magnetic circuit and stable winding support structure significantly enhance the product's short-circuit withstand capability and resistance to mechanical shock.
The corrugated oil tanks are produced on JASCO's specialized production lines and undergo degreasing, phosphating, and anti-corrosion treatments.
The corrugated fins accommodate oil volume fluctuations caused by temperature changes, while the complete isolation of the insulating oil from the atmosphere prevents oil degradation and reduces routine maintenance requirements.
The S11-M series employs an advanced insulation design (Class A) and complies with 35kV dielectric test standards. The series is equipped with a voltage regulation mechanism (±5% or ±2×2.5%) to stabilize secondary output voltage during grid fluctuations. Connection group options include Yyn0 or Dyn11; the Dyn11 configuration effectively suppresses zero-sequence harmonic currents, making it suitable for handling single-phase unbalanced loads and non-linear loads.
Utilizing an oil-immersed self-cooling (ONAN) method, the series covers a capacity range of 50 to 2500 kVA and complies with IEC 60076 and GB/T 1094 standards. Each transformer undergoes Factory Acceptance Testing (FAT) prior to shipment.
Product Specification
|
Parameter |
35kV Grade Specification |
Remarks |
|
Rated voltage |
35kV / 0.4kV (or other LV options) |
Primary feed voltage |
|
Power frequency withstand |
70kV for 1 minute |
Higher than 10/20kV |
|
Lightning impulse withstand |
170kV (peak) |
BIL level for 35kV |
|
Insulation level |
LI 170 AC 70 |
Per IEC 60076-3 |
|
Tapping range |
±2×2.5% or ±5% |
On HV side |
|
Impedance voltage |
6.5% – 8% (customizable) |
Higher than lower voltage classes |
|
Cooling type |
ONAN (Oil Natural Air Natural) |
Also available with fans (ONAF) |
|
Series |
Efficiency Level |
No-load Loss |
Load Loss |
Best Suited For |
|
S11 |
Standard |
Baseline |
Baseline |
Budget-constrained projects, low annual operating hours |
|
S13 |
Energy Saving |
↓20-30% vs S11 |
Similar to S11 |
Continuous operation, moderate energy cost sensitivity |
|
S20 |
High Efficiency |
↓30-40% vs S11 |
Lower than S13 |
Green energy projects, high annual hours, carbon reduction |
|
S22 |
Premium Ultra-Low Loss |
↓40%+ vs S11 |
Lowest available |
National grid, data centers, benchmark infrastructure |
Product Advantages
Excellent Energy Efficiency
Features a high-quality silicon steel core. Specifically designed for 35 kV medium-to-high voltage distribution networks, it offers stable operation, low load losses, and high cost-effectiveness.
High Short-Circuit Withstand Capability
Utilizes reinforced cylindrical or foil windings and a robust clamping system, enabling it to withstand the high-current surges associated with short-circuit faults.
Maintenance-Free Tank Design
Eliminates the external oil conservator in favor of a fully sealed corrugated tank design; requires no maintenance and is suitable for long-term outdoor operation.
Optimized for 35 kV Systems
Creepage distance and bushing design are optimized for 35 kV high-voltage systems. Equipped with a voltage regulation mechanism (±5% / ±2×2.5%); a Yyn0 connection group is available as an option to handle harmonics and unbalanced load conditions.
Reliable Insulation and Low Noise
Uses high-quality Class A insulation materials; passes comprehensive tests, including power-frequency withstand voltage and dielectric strength. Optimized core assembly processes effectively reduce magnetostriction effects and operational noise.
Quality Assurance and Customization
Capacity range of 50–2500 kVA; utilizes ONAN (Oil Natural Air Natural) cooling. Complies with IEC and national standards. JASCO offers OEM/ODM services for medium-to-high voltage orders or specific requirements.
Operating Environment Conditions
- Ambient temperature: Maximum ambient air temperature: +40 °C Minimum ambient air temperature: ‑25 °C 24‑hour average ambient temperature: ≤ +30 °C Annual average ambient temperature: ≤ +20 °C
- Altitude: ≤1000 m above sea level. Special customized design required if altitude exceeds 1000 m.
- Installation location: For outdoor installation. No severe mechanical vibration and violent shock.
- Atmospheric conditions: Ambient air shall not contain corrosive gas, conductive dust, flammable or explosive substances. Relative air humidity: ≤95% at +25 °C, no condensation allowed.
- Special requirement: If on‑site operating conditions deviate from above scope, please notify JASCO in advance for tailor‑made solution.
FAQ
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