3 Phase 20kv 400v Step Up Transformer Electricity 250kva 315kva 400kva Class Oil Immersed Transforme

3 Phase 20kv 400v Step Up Transformer Electricity 250kva 315kva 400kva Class Oil Immersed Transformer

1. Product Description

The 3 Phase 20kv 400v Step Up Transformer Electricity 250kva 315kva 400kva Class Oil Immersed Transformer is a professional medium-voltage step-up power conversion device designed for modern power distribution and distributed energy systems. Belonging to the standard 20kV class oil immersed transformer series, this three-phase power equipment supports stable voltage boost from 400V low-voltage electricity to 20kV medium-voltage power, covering three mainstream rated capacities of 250kVA, 315kVA and 400kVA to match diverse medium-load power generation and grid connection demands. Manufactured in full compliance with IEC 60076 and international power industry standards, this oil-filled step-up transformer adopts optimized low-loss electromagnetic design and mature industrial sealing technology, delivering consistent and reliable performance for both commercial and industrial power projects.

Built with high-grade grain-oriented silicon steel core and high-purity copper winding, this 20kV class three-phase step-up transformer effectively reduces no-load loss and operating temperature rise during long-term continuous operation. It features a standard Dyn11 vector group configuration, which optimizes three-phase current balance and enhances harmonic suppression capability compared with conventional transformer models. Adopting proven ONAN oil natural air natural cooling system and fully sealed welded steel tank structure, the equipment uses premium insulating transformer oil for dual insulation and heat dissipation functions. Unlike ordinary step-down distribution transformers, this customized 400V to 20kV step-up transformer is precisely calibrated for low-to-medium voltage power boosting, with stable voltage ratio, strong short-circuit resistance and low partial discharge. All capacity variants including 250kVA, 315kVA and 400kVA follow unified modular production standards, ensuring excellent versatility and field adaptability in 50Hz and 60Hz global power grid environments.

2. Core Purpose

The core purpose of the 20kV class oil immersed step up transformer is to resolve voltage grade mismatch issues in distributed power generation and local power transmission scenarios, achieving safe, efficient and low-loss conversion of 400V low-voltage electric energy into standard 20kV medium-voltage grid power. As a critical power boosting hub in medium-capacity power systems, it collects scattered low-voltage power resources and converts them into high-standard medium-voltage electricity, meeting technical requirements for 20kV grid connection, long-distance power transmission and regional power supply supplementation. The multi-capacity design ranging from 250kVA to 400kVA allows flexible load matching, eliminating equipment capacity waste and insufficient power margin in medium-scale power projects.

Beyond basic voltage step-up functions, this three-phase oil immersed electricity transformer undertakes key roles in power quality optimization and grid operation stabilization. It effectively balances three-phase output current, suppresses voltage fluctuation caused by intermittent power generation, and filters harmonic interference generated by inverter equipment. By boosting 400V power to 20kV medium voltage, it greatly reduces line transmission loss during long-distance power delivery, improving overall power utilization efficiency. For off-grid power areas and industrial self-power supply systems, this durable oil immersed step-up equipment stabilizes power output quality, guarantees continuous power supply, and provides reliable technical support for regional power grid upgrading and load capacity expansion.

3. Application Scenarios

3.1 Medium-Scale Distributed New Energy Grid Connection

This 3 Phase 20kv 400v Step Up Oil Immersed Transformer is the core supporting equipment for medium-capacity distributed photovoltaic power stations, small wind farm systems and industrial energy storage power generation projects. Most new energy power generation units output standard 400V three-phase low-voltage power, which cannot be directly connected to 20kV municipal medium-voltage grids. The 250kVA, 315kVA and 400kVA capacity models perfectly match the power output scale of medium-sized new energy projects, steadily boosting low-voltage power to compliant 20kV grid voltage, realizing safe grid-connected power transmission and efficient recycling of clean energy resources.

3.2 Industrial Park Self-Power Supply & Power Supplement

It is widely applied in medium-sized industrial parks, township manufacturing workshops, processing factories and light industrial production bases. Many industrial zones face insufficient municipal grid power supply during peak consumption periods, and enterprises are equipped with diesel generators and distributed power generation units to supplement power. This 20kV class step-up transformer can boost self-generated 400V electricity to 20kV medium voltage for internal regional power distribution or grid feedback, effectively alleviating grid load pressure and ensuring stable operation of industrial production equipment and electromechanical systems.

3.3 Rural & Suburban Power Grid Renovation Projects

In rural power grid upgrading and suburban regional power optimization construction, this medium-capacity oil immersed step-up transformer serves as key auxiliary power distribution equipment. Rural scattered power generation and resident decentralized power sources can be collected and boosted to 20kV medium voltage for centralized transmission and distribution, solving the problems of short transmission distance and high line loss of traditional 400V low-voltage power supply. It effectively improves rural power grid coverage, enhances terminal power supply stability, and optimizes the operational structure of urban and rural 20kV distribution networks.

3.4 Remote Engineering & Off-Grid Power Transmission

The equipment is well suited for remote field construction sites, island power supply systems, rural water conservancy projects and other off-grid scenarios without complete medium-voltage grid coverage. Off-grid power generation equipment mostly outputs 400V low-voltage power, which is not suitable for long-distance transmission. This robust oil immersed step-up transformer converts low-voltage electricity to 20kV medium voltage, extending power transmission distance, reducing power loss, and realizing stable centralized power supply for remote engineering facilities and scattered residential areas.

4. Product Features

4.1 Multi-Capacity Matching, Wide Application Adaptability

This 20kV class 3 phase 400V to 20kV step up transformer offers three practical capacity options of 250kva, 315kva and 400kva, fully covering medium-capacity power boosting demands for new energy grid connection, industrial power supplement and rural power grid reconstruction. Users can select targeted capacity specifications according to actual power generation power and load growth plans, realizing precise load matching. All models feature unified installation dimensions and technical parameters, with strong compatibility and interchangeability in engineering design, procurement and on-site replacement.

4.2 Professional Step-Up Optimization, Stable Power Quality

Specially optimized for 400V to 20kV voltage boosting working conditions, this three-phase electricity transformer adopts precise coil turns ratio calibration and advanced magnetic circuit optimization design. It achieves accurate and stable medium-voltage output with extremely low voltage deviation, fully meeting 20kV grid access standards. The standard Dyn11 connection group effectively suppresses three-phase imbalance and harmonic pollution, improves zero-sequence fault tolerance, and ensures clean and stable power quality during long-term grid-connected operation, avoiding grid fluctuation caused by new energy power generation volatility.

4.3 Low-Loss Oil Immersed Structure, Energy-Saving & Durable

Adopting high-quality low-loss silicon steel core and full copper winding structure, this oil immersed power transformer greatly reduces no-load loss and load loss compared with conventional transformer products. The fully sealed welded tank body completely isolates internal insulating oil from external air, moisture and dust, preventing oil emulsification, oxidation and insulation aging. The natural oil circulation heat dissipation system operates efficiently without auxiliary cooling equipment, maintaining low temperature rise under continuous full-load operation. This energy-saving design effectively cuts long-term power consumption and operation costs for users.

4.4 Strong Structural Stability & High Operation Safety

The transformer body adopts reinforced coil compression structure and multi-layer composite insulation materials, significantly improving short-circuit impact resistance and mechanical stability. It is equipped with complete overvoltage, overcurrent and short-circuit protection mechanisms, which can quickly isolate faults to protect grid and equipment safety during abnormal working conditions. The external tank body adopts anti-corrosion and weather-resistant coating, with excellent rainproof, dustproof and lightning protection performance, adapting to long-term outdoor unattended operation in high temperature, humid and windy harsh environments.

4.5 Low Maintenance & High Comprehensive Cost Performance

This sealed 20kV step-up oil immersed transformer features maintenance-free operation under conventional working conditions, eliminating frequent oil replacement and daily overhaul work required by open-type transformers. The modular structural design simplifies on-site installation, commissioning and later inspection procedures, shortening project construction cycles. With low failure rate, low operating noise and 30+ years of service life, it delivers outstanding long-term economic benefits for medium-scale power distribution and new energy projects.

5. Frequently Asked Questions (FAQ)

5.1 What are the differences between 20kV step-up transformers and conventional 10kV step-up transformers?

The core difference lies in transmission capacity and application scenarios. The 3 Phase 20kv 400v Step Up Transformer supports 20kV medium-voltage transmission, which carries larger power capacity and has lower line loss than 10kV equipment under the same transmission distance. It is more suitable for medium-capacity power generation and medium-distance power transmission projects, while 10kV transformers are mostly used for short-distance small-load grid connection. In addition, 20kV class oil immersed transformers have higher insulation standards and stronger grid fluctuation resistance, making them more adaptable to complex industrial and suburban power grid environments.

5.2 How to choose between 250kva, 315kva and 400kva capacity models?

Capacity selection depends on actual power generation output and future load expansion requirements. The 250kVA model is ideal for small distributed photovoltaic systems and low-power industrial supplementary power supply with stable medium and low loads. The 315kVA model is the most versatile option, suitable for most standard medium-sized new energy power stations and rural power grid renovation projects. The 400kVA high-capacity model is recommended for medium industrial parks and high-power distributed power generation projects with large peak load differences. It is advised to reserve 10%–20% load margin to avoid long-term full-load operation and extend transformer service life.

5.3 Is regular insulating oil replacement required for this 20kV class oil immersed transformer?

This series of fully sealed 20kV class oil immersed transformers does not require frequent oil replacement and routine maintenance. The closed welded tank structure fundamentally blocks external moisture and air, ensuring long-term stability of internal high-purity insulating oil. Daily operation only requires simple visual inspection of oil temperature, operating noise and tank anti-corrosion status. Professional oil quality sampling and testing is only needed every 3 to 5 years, and oil replacement is only carried out when insulation performance indicators fail to meet standards. Compared with open-type transformers, it greatly reduces later maintenance workload and operational costs.