630kva 800kva 35kv 400v Oil Immersed Transformer

630kva 800kva 35kv 400v Oil Immersed Transformer

1. Product Description

The 630kVA 800kVA 35kV 400V oil immersed transformer is a standard S11/S13 energy-saving three-phase step-down power transformer designed for 35kV medium and high voltage power grid systems. As a mainstream medium-capacity oil-filled distribution transformer widely deployed in industrial and municipal power projects, this 35kV to 400V oil immersed power equipment reliably converts 35kV high-voltage grid power into standard 400V low-voltage power, perfectly matching the power supply requirements of industrial production equipment, commercial electrical systems and municipal terminal power facilities. Manufactured in strict accordance with IEC60076 and GB/T6451 industry standards, this sealed oil immersed transformer undergoes rigorous factory testing to ensure stable performance under long-term continuous load operation.

Adopting high-quality grain-oriented cold-rolled silicon steel core and high-purity oxygen-free copper winding structure, the 630kVA and 800kVA 35kV 400V oil immersed distribution transformer effectively reduces no-load loss and operational heat generation compared with traditional old-model transformers. Equipped with fully sealed corrugated oil tank and mature ONAN oil natural self-cooling technology, the equipment completely isolates internal insulating oil from external air, dust and moisture, preventing oil aging and insulation degradation. With moderate load capacity, strong short-circuit resistance and excellent weather adaptability, this 35kV medium-voltage transformer serves as core power transformation equipment for urban power grid renovation, industrial park power distribution and outdoor substation construction projects.

2.  Technical Parameters

3. Core Purpose

The core purpose of the 630kVA and 800kVA 35kV 400V oil immersed transformer is to deliver safe, stable and efficient voltage step-down conversion for 35kV high-voltage power distribution systems. This practical oil-filled step-down transformer solves the voltage level mismatch between high-voltage transmission power grids and low-voltage terminal electrical equipment, converting inaccessible 35kV industrial high voltage into standard 400V usable power for industrial production, commercial operation and municipal public power supply.

In daily grid operation, this three-phase oil immersed power transformer undertakes multiple critical functions including grid voltage stabilization, three-phase load balancing, power distribution shunting and circuit safety isolation. It effectively suppresses power grid harmonic interference, reduces voltage fluctuation and instantaneous current surge caused by frequent load switching, and greatly improves regional power supply quality and grid operational stability. Designed for medium and large continuous power loads, it eliminates power supply instability and equipment damage risks caused by overload operation, optimizes the operating efficiency of 35kV regional power grids, and provides reliable long-term power guarantee for various industrial and municipal power consumption units.

4. Application Scenarios

Featuring medium-large load capacity, high operational stability and strong environmental adaptability, the 630kVA 800kVA 35kV/400V oil immersed power transformer covers mainstream medium-heavy load power supply scenarios. It is the most cost-effective energy-saving power transformation equipment for 35kV power grid construction, capacity expansion and industrial supporting projects:

• Medium Industrial Park Power Distribution: Suitable for standardized industrial parks, machinery manufacturing factories, building material processing plants and light chemical production bases. The 630kVA oil immersed transformer matches conventional medium-load production power demand, while the 800kVA model adapts to factories with multi-equipment parallel operation and higher peak power consumption.

• Urban & Rural 35kV Power Grid Renovation: Widely used in urban suburban grid upgrading, county-level regional power grid construction and rural high-standard power grid reconstruction. It replaces old high-loss transformers to improve power supply efficiency and meet the growing industrial and residential power consumption demand.

• Key Municipal Public Infrastructure: Ideal for district hospital power systems, comprehensive campus power distribution, urban community service centers and large scenic area supporting facilities, ensuring 24-hour stable and safe power supply for public service operations.

• Outdoor Ground-mounted Substation Projects: With excellent rainproof, dustproof, anti-corrosion and anti-aging performance, it adapts to outdoor open-air substations and 35kV overhead line power distribution stations, supporting long-term unattended outdoor continuous operation.

• Distributed New Energy Grid Connection: Matched with medium-sized rooftop photovoltaic power stations and decentralized wind power generation projects, completing high-stability voltage conversion and grid-connected power distribution for new energy equipment to stabilize grid access power quality.

• Mining & Field Engineering Power Supply: Applicable for long-term power guarantee of mining sites, water conservancy hubs and large-scale road construction projects, with strong load impact resistance to cope with complex and harsh field power consumption environments.

5. Product Features

This 630kVA & 800kVA 35kV 400V oil immersed distribution transformer adopts upgraded S13 energy-saving design and optimized manufacturing technology. Compared with traditional ordinary transformers, it has comprehensive advantages in energy-saving performance, operational safety, structural durability and later maintenance cost, fully adapting to high-standard operation requirements of modern 35kV high-voltage power grids:

• Low Loss & High Energy Efficiency: The core iron core adopts high-permeability cold-rolled silicon steel sheets with full oblique lap stacking process, minimizing magnetic leakage and no-load iron loss. The integral oxygen-free copper winding structure effectively reduces internal resistance and load copper loss. All loss indicators are far lower than national standard values, effectively cutting long-term grid operation and power consumption costs for users.

• Stable Voltage Output & Strong Anti-interference: Advanced Dyn11 vector group design accurately balances three-phase voltage and current, effectively suppresses grid harmonics and eliminates voltage deviation. The multi-grade off-circuit voltage regulation device adapts to different regional grid voltage fluctuations, ensuring constant and standard 400V low-voltage output and improving terminal power supply quality.

• Fully Sealed & Durable Structure: Integrated fully sealed corrugated oil tank design completely isolates internal insulating oil from external air, preventing oil oxidation, moisture ingress and dust pollution. The elastic corrugated structure automatically adjusts internal pressure with temperature changes, avoiding tank deformation and oil leakage, and greatly extending equipment service life.

• Excellent Environmental Adaptability: The whole machine adopts thickened steel plate welding and high weather-resistant anti-corrosion electrostatic spraying process, resisting ultraviolet aging, rain erosion and wind and sand impact. It can operate stably in high temperature, low temperature, high humidity and dusty harsh environments all year round.

• High Safety & Strong Short-circuit Resistance: Strict 35kV high-voltage insulation design ensures high insulation strength and breakdown resistance. The equipment has excellent over-current, over-voltage and overload protection capabilities, with strong short-circuit impact resistance and low operational failure rate, fully guaranteeing safe operation of power grid and terminal industrial equipment.

• Low Noise & Easy Maintenance: Optimized vibration reduction structure and mute winding technology effectively reduce operating noise, meeting industrial and urban environmental protection standards. The ONAN self-cooling mode requires no auxiliary cooling equipment, and standardized modular components make daily inspection, oil quality detection and routine maintenance simple and efficient, lowering later operation and maintenance costs.

6. FAQ (Frequently Asked Questions)

Q1: How to select between 630kVA and 800kVA 35kV 400V oil immersed transformers?

Both models share identical 35kV/400V voltage level, structural process and safety standards, with the core difference lying in load capacity and applicable scenarios. The 630kVA oil immersed transformer is suitable for medium-load scenarios such as single medium-sized factories, conventional municipal facilities and suburban regional power supply, with balanced energy consumption and stable daily operation. The 800kVA oil filled distribution transformer has larger rated capacity and stronger instantaneous overload resistance, ideal for medium-heavy load scenarios including multi-workshop industrial parks, centralized commercial districts and key grid renovation projects with higher peak power consumption. It is recommended to reserve 20%–30% load margin during selection to adapt to future power consumption growth.

Q2: Can this 35kV 400V oil immersed transformer operate stably outdoors all year round?

Yes, this series of 630kVA/800kVA 35kV power transformers is fully optimized for outdoor harsh working conditions. The fully sealed oil tank structure completely isolates internal insulating oil from external humid and dusty air, avoiding internal insulation damp failure and insulating oil deterioration. The overall high weather-resistant anti-corrosion coating resists long-term ultraviolet radiation, rain erosion, snow freezing and wind and sand deposition. The mature ONAN oil immersed self-cooling system ensures stable heat dissipation during 24-hour continuous operation, with extremely low failure rate, fully meeting the requirements of outdoor unattended long-term power distribution operation.

Q3: What routine maintenance is required for 35kV medium-capacity oil immersed transformers?

This energy-saving oil immersed transformer has low daily maintenance threshold and stable operational performance. Operators need to regularly check the insulating oil level and oil clarity to ensure the oil level is within the standard scale and replace turbid and aging insulating oil in a timely manner. Clean dust and sundries on the surface of heat dissipation corrugations regularly to guarantee unobstructed heat dissipation and prevent equipment overheating faults. Inspect the tightness of high and low voltage wiring terminals and oil tank sealing points to avoid oil leakage and poor contact. In addition, test insulation resistance and operating temperature periodically to prohibit long-term overload operation. With standardized routine maintenance, the equipment service life can reach more than 20 years.