As a reliable power transformer supplier, we supply high-performance oil immersed power distribution transformer and substation power transformers. This 35kV three phase power transformer is widely used for industrial power transformers projects, featuring off-circuit voltage regulation, low loss and stable operation for substation and industrial power grid systems.
This 35kV oil immersed off-circuit tap changer power transformer is painted in industrial light grey, with compact cuboid steel tank structure, equipped with high-voltage porcelain bushings, conservator, radiator, oil drain valves and side maintenance ladder.
The core adopts high-grade grain-oriented silicon steel sheet, copper windings with robust insulation. Customizable overall dimensions according to capacity.
It functions to step up/down 35kV grid voltage for power transmission and distribution.
As professional power transformer supplier, we provide competitive factory price for bulk orders, reliable quality for substation and industrial projects, our oil immersed power distribution transformer and substation power transformers have gained trust from global buyers.
Product Features
• Off-circuit Tap Voltage Regulation
This three phase power transformer adopts no-excitation tap changer. Voltage adjustment can be done offline to adapt to grid voltage fluctuation, simple structure and low failure rate, ideal for stable industrial power transformers application scenarios.
• Low Loss & High Efficiency
High-quality grain-oriented silicon steel core minimizes no-load loss, optimized winding design reduces load loss, saving long-term electricity operating cost for power stations and substations.
• Robust Oil Immersed Cooling Structure
The oil immersed power distribution transformer uses ONAN oil natural air cooling system. Radiators on tank side efficiently dissipate heat to maintain stable working temperature under continuous rated load.
• Heavy-duty & Anti-corrosion Enclosure
Welded thick steel tank with anti-rust and weatherproof grey coating, resistant to dust, moisture and outdoor harsh environment, specially built for substation power transformers.
• Customizable Design & Flexible Supply
As professional power transformer supplier, we support customized capacity, voltage combination and accessories. We offer attractive bulk pricing to help customers control project budget.
Specifications & Parameters
| Category | Specification / Description |
| Rated Voltage | 35kV / 0.4kV (customizable) |
| Type | Three Phase, Oil Immersed, Off-circuit Tap Changer |
| Cooling Method | ONAN |
| Phase | 3 Phase |
| Frequency | 50Hz /60Hz |
| Insulation Medium | Mineral Transformer Oil |
| Tap Range | ±2×2.5% (standard) |
| Core Material | Grain-oriented Silicon Steel |
| Winding Material | Copper |
| Tank Color | Light Grey Industrial Paint |
| Application | Substation, Industrial Power Grid, Power Distribution Project |
Key Performance Data (Efficiency Tiers for 35kV Series)
The table below outlines the guaranteed no-load and load loss values for different efficiency grades. Short-circuit impedance is designed as per requirements (e.g., 7%, 8%, 10% for various capacities).
| Rated Capacity (kVA) | Efficiency Grade 1 |
Efficiency Grade 2 |
Efficiency Grade 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 | 1.7 | 20.7 | 2.0 | 20.7 | 2.4 | 21.9 |
| 5000 | 2.4 |
28.2 | 2.8 | 28.2 | 3.5 | 29.7 |
| 10000 | 4.8 | 40.8 | 5.7 | 40.8 | 7.0 | 43.0 |
| 20000 | 7.9 | 71.6 | 9.4 | 71.6 | 11.5 | 75.5 |
| 31500 | 11.1 | 100.8 | 13.1 | 100.8 | 16.2 | 106.4 |
Packaging, Warranty & Certifications Packaging：
The substation power transformers will be fixed firmly on heavy-duty steel skid. Main tank is protected by reinforced steel frame for ocean & land shipment. Radiators, bushings and spare parts are packed in solid plywood crates. Desiccant is placed inside the tank to keep insulation dry during transit.
Warranty：
18 months warranty from shipment date or 12 months after commissioning, whichever comes first. The warranty covers manufacturing defects of our industrial power transformers. Our technical team provides remote guidance for installation, commissioning and troubleshooting.
Certifications & Testing：
Our three phase power transformer follows ISO9001 quality management system. Each transformer passes routine and type tests including winding resistance, ratio test, no-load & load loss, dielectric withstand and short-circuit impedance test. We can provide IEC, GB1094, CE, GOST, EAC certifications upon request.
Use Scenarios
Power Distribution for Industrial Substations
This substation power transformers solution is widely deployed in industrial substations to convert high-voltage grid power into usable low voltage for factory production lines. As a three phase power transformer, it delivers steady power supply and works perfectly in long-term continuous operation scenarios. The off-circuit tap changer design suits sites with infrequent grid voltage changes, an excellent choice for oil immersed power distribution transformer projects.
Grid & Municipal Power Supply Projects
Our industrial power transformers serve municipal power distribution networks, rural power upgrading and small power plant transmission systems. It stabilizes voltage for regional power grids, ensures safe power delivery for residential and commercial loads.
Mining & Heavy Industry Power Systems
For mining, chemical and metallurgical industrial projects, this heavy-duty transformer withstands harsh site conditions. As an experienced power transformer supplier, we tailor parameters to match special power demands of heavy industrial facilities.
FAQ
1. What is the difference between off-circuit tap changer and on-load tap changer for this 35kV transformer?
This three phase power transformer uses off-circuit tap changer, voltage adjustment must be performed when the transformer is powered off. It has simpler structure, lower cost and less maintenance requirement, suitable for projects without frequent voltage adjustment. OLTC version is available if you need live voltage regulation.
2. Can you customize the capacity and voltage ratio of your oil immersed power distribution transformer?
Yes. As a professional power transformer supplier, we fully customize capacity, voltage combination, accessories and dimensions for substation power transformers to meet your local grid and project requirements.
3. What cooling method does this industrial power transformers adopt?
It uses ONAN (Oil Natural Air Natural) cooling system. Heat is transferred through transformer oil and radiators, suitable for most conventional substation and industrial distribution applications.
4. What documents can you provide before shipment?
We can supply factory test reports, drawings, operation manuals, and relevant certificates such as IEC, GB, CE, GOST and EAC for your customs clearance and project approval.
5. What kind of after-sales support can I get?
We provide remote technical guidance for installation, commissioning and troubleshooting. Our warranty is 18 months after shipment or 12 months after commissioning (whichever comes first), covering manufacturing defects.
