Oil-Immersed Transformer
Product Overview
The core-coil assembly is suspended in a steel tank filled with insulating oil, which acts as both a cooling and insulating medium, circulating via convection for heat dissipation.
Core Specifications:
Standards: Complies with IEC60076 & SEC.
Rated frequency: 50Hz/60Hz.
Capacity range: 160kVA – 4000kVA (with technical parameters for models up to 31500kVA provided).
Voltage & tapping: HV options include 35kV, 35~38.5kV; tapping range ±2×2.5% or ±5% (off-circuit tap changer with 5 positions).
Cooling method: ONAN (Oil Natural Air Natural).
Temperature requirements: Ambient temperature ≤55°C; max temperature rise (top oil: 45°C, average winding: 50°C); operating temperature must be below 85°C to avoid oil deterioration (recommended daily average: ~30°C).
Vector group: Dyn11 (primary), Yd11/Ynd11 (per technical parameters).
Advantage
Cost-Effectiveness More affordable than dry-type transformers of the same capacity (up to 50% lower).
Cooling & Voltage Performance Superior cooling efficiency (oil is a better medium); no voltage capacity limit (dry-type transformers are restricted to below 35kV).
Versatility Functions as both power transformers and distribution transformers (dry-type transformers typically only connect intermediate nodes to end-users).
Environmental & Installation Adaptability Easier to recycle than dry-type transformers; compact size, ideal for outdoor installation (to mitigate risks of oil spills or accidents).
Technical Parameter (S11 Series: 35kV Low-Loss, Non-Excitation Voltage Regulation)
| Rated Capacity (kVA) | Voltage Combination | Vector Group | No-Load Loss (W) | Load Loss (W, 75℃) | No-Load Current (%) | Short-Circuit Impedance (%) |
| 630 | HV: 35kV (±5%); LV: 3.15/6.3/10.5kV | Yd11 | 830 | 7870 | 1.10 | 6.5 |
| 800 | Same as above | Yd11 | 980 | 9410 | 1.00 | 6.5 |
| 1000 | Same as above | Yd11 | 1150 | 11540 | 1.00 | 6.5 |
| 1250 | Same as above | Yd11 | 1410 | 13940 | 0.90 | 6.5 |
| 1600 | Same as above | Yd11 | 1700 | 16670 | 0.80 | 6.5 |
| 2000 | Same as above | Yd11 | 2180 | 18380 | 0.70 | 6.5 |
| 2500 | Same as above | Yd11 | 2560 | 19670 | 0.60 | 6.5 |
| 3150 | HV: 35~38.5kV (±5%); LV: 3.15/6.3/10.5kV | Yd11 | 3040 | 23090 | 0.56 | 7.0 |
| 4000 | Same as above | Yd11 | 3620 | 27360 | 0.56 | 7.0 |
| 5000 | Same as above | Yd11 | 4320 | 31380 | 0.48 | 7.0 |
| 6300 | Same as above | Yd11 | 5250 | 35060 | 0.48 | 7.5 |
| 8000 | HV: 35~38.5kV (±2×2.5%); LV: 3.15/3.3/6.3/6.6/10.5/11kV | Ynd11 | 7200 | 38480 | 0.42 | 7.5 |
| 10000 | Same as above | Ynd11 | 8700 | 45320 | 0.42 | 7.5 |
| 12500 | Same as above | Ynd11 | 10080 | 53870 | 0.40 | 8.0 |
| 16000 | Same as above | Ynd11 | 12160 | 65840 | 0.40 | 8.0 |
| 20000 | Same as above | Ynd11 | 14400 | 79520 | 0.40 | 8.0 |
| 25000 | Same as above | Ynd11 | 17020 | 94050 | 0.32 | 8.0 |
| 31500 | Same as above | Ynd11 | 20220 | 112860 | 0.32 | 8.0 |
Application
General Environments: Well-ventilated indoor and outdoor settings, suitable for urban and rural power transmission and distribution networks.
Harsh Environments: Specialized models for coastal areas, chemical plants, coal mines, and other demanding conditions.
Key Sectors: Petrochemical industry, power systems, transportation, and other industrial fields.
