250kva 315kva 35kv 400v Oil Immersed Transformer

250kva 315kva 35kv 400v Oil Immersed Transformer

1. Product Description

The 250kVA 315kVA 35kV 400V oil immersed transformer is a high-efficiency three-phase medium and high voltage step-down distribution transformer designed for 35kV power grid systems. As a mainstream S11/S13 energy-saving oil-filled power transformation device, this 35kV to 400V oil immersed power transformer is widely deployed in urban and rural power grid infrastructure, industrial power distribution stations and outdoor centralized substation projects. It professionally converts 35kV high-voltage grid electricity into standard 400V low-voltage power, fully matching the operating voltage requirements of civil, commercial and industrial terminal electrical equipment.

Manufactured complying with IEC60076 and GB1094 international and national electrical standards, the 250kVA/315kVA 35kV 400V oil immersed distribution transformer adopts high-quality grain-oriented cold-rolled silicon steel core and high-purity oxygen-free copper winding structure. The optimized fully sealed corrugated oil tank and ONAN oil immersed self-cooling technology effectively reduce no-load loss and operating heat generation, solving common problems of high energy consumption and poor heat dissipation in traditional transformers. With stable insulation performance, strong overload resistance and excellent weather resistance, this medium-capacity power transformer can adapt to long-term continuous full-load operation in various indoor and outdoor complex environments, serving as core power distribution equipment for medium-scale power load scenarios.

2. Technical Parameters

3. Core Purpose

The core purpose of the 250kVA and 315kVA 35kV 400V oil immersed transformer is to realize safe, efficient and stable step-down conversion in 35kV high-voltage power distribution systems. This oil-filled step-down transformer bridges the voltage gap between high-voltage power grids and low-voltage terminal equipment, converting inaccessible 35kV industrial high voltage into usable 400V low-voltage power for production and domestic use. It is a key core device for medium-capacity power grid voltage transformation and power distribution.

In actual power grid operation, this three-phase oil immersed distribution transformer undertakes multiple core functions including voltage stabilization, power distribution shunting, circuit isolation and load protection. It can effectively suppress grid harmonic interference, balance three-phase voltage and current, reduce voltage fluctuation and current surge, and greatly improve overall power supply quality and grid operation stability. For medium-scale centralized power loads, it provides continuous and reliable power guarantee, avoids power supply faults and equipment damage caused by overload and voltage instability, and optimizes the operational efficiency of regional 35kV power supply systems.

4. Application Scenarios

The 250kVA 315kVA 35kV/400V oil immersed power transformer features large load capacity, strong environmental adaptability and high operational stability. It covers medium-load power supply scenarios in civil, industrial, public infrastructure and new energy fields, and is the preferred energy-saving transformer for 35kV medium and small-scale power distribution projects:

• Urban & Rural Power Grid Renovation: Suitable for urban community centralized power supply, township power grid upgrading and suburban residential area power distribution. The 250kVA model adapts to medium-sized community power loads, while the 315kVA model meets the power demand of densely populated residential areas and supporting commercial facilities.

• Medium-sized Industrial Park & Factory Power Supply: Ideal for small and medium-sized processing factories, mechanical manufacturing workshops, building material plants and industrial zone supporting power distribution. It provides stable 400V industrial power for production lines, mechanical equipment and auxiliary electrical systems, adapting to long-term continuous industrial power consumption.

• Public Infrastructure Supporting Power Distribution: Widely used in campus overall power supply, hospital power distribution systems, urban comprehensive service centers, large shopping malls and scenic area supporting facilities, ensuring safe and uninterrupted power supply for public service equipment.

• Outdoor Centralized Substation Projects: With excellent rainproof, dustproof, anti-corrosion and anti-aging performance, it is applicable to outdoor ground-mounted substations, overhead line power distribution stations and remote regional power supply points, supporting long-term unattended outdoor operation.

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

• Engineering & Mining Temporary Power Supply: Suitable for long-term power supply of mining sites, large water conservancy projects, highway construction projects and field operation sites, with strong load impact resistance to adapt to complex and changeable field power consumption conditions.

5. Product Features

This 250kVA & 315kVA 35kV 400V oil immersed transformer adopts upgraded energy-saving design and mature manufacturing technology, with prominent advantages in energy-saving performance, operational safety, structural durability and later maintenance. It has higher cost performance and operational stability than traditional ordinary transformers in 35kV power distribution scenarios:

• Low Loss & High Energy Efficiency: The iron core is made of high-permeability cold-rolled silicon steel sheets with full oblique lap stacking process, which minimizes magnetic leakage and no-load iron loss. The integral oxygen-free copper winding reduces resistance and copper loss during load operation. The overall power consumption is far lower than national standard values, effectively reducing long-term grid operation and power consumption costs.

• Stable Voltage Output & Strong Anti-interference: Adopts advanced Dyn11 vector group design, which can effectively balance three-phase current, suppress power grid harmonics and stabilize output voltage. The built-in multi-grade off-circuit voltage regulation device can adapt to different regional grid voltage deviation, ensuring constant and standard 400V low-voltage output and improving terminal power supply quality.

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

• Excellent Environmental Adaptability: The whole machine adopts thickened steel plate welding and high weather resistance anti-corrosion electrostatic spraying process, which resists ultraviolet aging, rain erosion, wind and sand impact. It can operate stably in high temperature, low temperature, high humidity and dusty harsh environments, with strong field adaptability.

• 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 operation failure rate, effectively ensuring grid and terminal equipment operation safety.

• Low Noise & Easy Maintenance: Optimized vibration reduction structure and mute winding technology reduce operating noise significantly. The ONAN self-cooling mode requires no auxiliary cooling equipment, realizing low-noise and environmental-friendly operation. The compact integrated structure supports flexible installation, and standardized internal components make daily inspection and routine maintenance simple and efficient, reducing later operation and maintenance costs.

6. FAQ (Frequently Asked Questions)

Q1: How to choose between 250kVA and 315kVA 35kV 400V oil immersed transformers?

The two models share the same 35kV/400V voltage level, structural technology and safety standards, with the main difference lying in load capacity and applicable scenarios. The 250kVA oil immersed transformer is suitable for medium-load scenarios such as medium-sized residential communities, small and medium-sized workshops and ordinary public facilities, with lower no-load loss and more energy-saving operation under conventional load. The 315kVA oil filled distribution transformer has larger rated load capacity and stronger instantaneous overload resistance, which is more suitable for scenarios with stable medium and high load power consumption such as centralized commercial districts, medium-sized industrial parks and key municipal supporting projects. It is recommended to select the model according to actual peak power consumption and reserved load margin.

Q2: Can this 35kV 400V oil immersed transformer work stably in outdoor harsh environments?

Yes, this series of 250kVA/315kVA 35kV power transformers is specially optimized for outdoor working conditions. The whole machine adopts fully sealed anti-corrosion structure and weather-resistant coating, which can effectively resist rainwater erosion, snow freezing, wind and sand deposition and ultraviolet aging. The closed insulating oil system will not be affected by external humid and dusty environment, avoiding internal damp insulation failure and oil deterioration. The ONAN oil immersed self-cooling system can automatically adapt to seasonal temperature changes, supporting 24-hour long-term unattended continuous outdoor operation, which is very suitable for outdoor substation and overhead power distribution projects.

Q3: What are the key daily maintenance points for 35kV 400V oil immersed transformers?

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