20KV 400V Three Phase Oil Immersed Transformers
1. Product Overview
The 20KV 400V Three Phase Oil Immersed Transformers are high-efficiency, low-loss medium-voltage distribution power transformers designed for modern industrial, municipal and utility power grid systems. Built to comply with international IEC 60076 and ANSI power equipment standards, this series of three-phase oil immersed distribution transformers specializes in converting 20kV medium high-voltage grid power into standard 400V three-phase low-voltage power for commercial, residential and industrial end-users. As a mainstream core device for 20kV class power distribution networks, it adopts advanced fully sealed oil cooling technology and optimized core winding structure to deliver stable, safe and energy-saving voltage transformation performance.
Widely recognized as a reliable medium-voltage power conversion solution, this three-phase oil immersed transformer supports both outdoor floor-mounted and indoor substation installation, adapting to 50Hz and 60Hz global power frequency systems. Different from traditional 10kV distribution transformers, the upgraded 20KV 400V oil immersed transformer features higher insulation grade, longer power supply radius and lower long-distance transmission loss, perfectly matching the capacity expansion and upgrading demands of modern urban and rural power grids. With flexible load adaptability, durable structural design and low operational failure rate, it has become the most popular standard three-phase power transformer for new energy supporting projects, industrial park power supply and municipal power distribution engineering worldwide.
2. Core Product Features
2.1 Accurate 20KV to 400V Voltage Transformation Performance
This professional three-phase oil immersed transformer adopts a standard 20kV/0.4kV voltage transformation ratio, achieving precise and stable step-down conversion for medium-voltage power grids. Equipped with a reliable off-circuit no-load tap changer, the equipment allows manual voltage adjustment under power-off conditions to compensate for long-distance line voltage drop and grid voltage fluctuation during peak power consumption periods. The symmetrical three-phase winding structure ensures balanced voltage and current output, effectively avoiding three-phase unbalanced operation, reducing power quality distortion and guaranteeing consistent 400V rated output for terminal electrical equipment.
2.2 Low-Loss Energy-Saving & High Power Transmission Efficiency
Manufactured with high-quality grain-oriented cold-rolled silicon steel core and high-purity oxygen-free copper windings, the 20KV 400V three-phase oil immersed transformer significantly reduces no-load loss, load loss and magnetic leakage loss during continuous operation. The optimized magnetic circuit design minimizes redundant energy consumption, realizing ultra-low energy loss and high power transmission efficiency that meets international energy-saving standards. Compared with conventional old-style power transformers, this energy-saving oil immersed distribution transformer effectively cuts down long-term grid operating costs and carbon emissions, supporting low-carbon and eco-friendly power grid construction.
2.3 Fully Sealed Oil Immersed Cooling & Long Service Life
Featuring a fully sealed corrugated oil tank structure without conservator design, the three-phase oil immersed transformer uses high-purity insulating mineral oil as dual cooling and insulation medium. The natural circulating oil cooling system efficiently absorbs and dissipates heat generated by core and winding operation, maintaining stable temperature rise even under full-load and intermittent overload working conditions. The fully sealed structure completely isolates internal components from external air, dust and moisture, preventing insulating oil aging, oxidation and moisture absorption. This design avoids internal insulation degradation and short-circuit faults, extending the equipment service life up to more than 30 years and greatly reducing daily maintenance workload.
2.4 Superior Insulation & Strong Grid Adaptability
With upgraded medium-voltage insulation structure and high-strength insulating materials, the 20KV class three-phase oil immersed transformer has excellent dielectric strength and surge resistance, adapting to complex 20kV medium-voltage grid operating environments. It can resist grid voltage surge, instantaneous load impact and environmental interference, maintaining stable operation under slight grid fluctuation. The whole machine supports wide ambient temperature adaptation from -25℃ to +40℃, with outstanding weather resistance, anti-corrosion and anti-aging performance, suitable for harsh outdoor open-air and humid industrial environments that ordinary dry-type transformers cannot adapt to.
2.5 Complete Safety Protection & Stable Operational Reliability
This industrial three-phase oil immersed power transformer is equipped with multiple built-in safety protection mechanisms, including over-current protection, short-circuit protection, over-temperature protection and pressure relief protection. It can automatically cut off power supply in case of circuit faults, overload and overheating, effectively protecting power grid operation and terminal electrical equipment safety. The integrally fixed internal structure enhances mechanical stability and short-circuit withstand capability, avoiding component loosening and operational failure caused by vibration and impact, realizing long-term unattended safe and stable operation for power distribution systems.
3. Core Uses
The 20KV 400V Three Phase Oil Immersed Transformer serves as the core voltage conversion and power distribution equipment for 20kV medium-voltage three-phase AC power systems. Its primary core function is to step down high 20kV transmission line voltage to standard 400V low-voltage three-phase power, solving the voltage level mismatch between medium-voltage power grids and industrial, commercial and civil terminal electrical loads.
In practical power system operation, this energy-saving oil immersed distribution transformer stabilizes terminal power supply voltage, suppresses grid harmonic interference and voltage fluctuation, and reduces power transmission loss during medium and short-distance power distribution. It undertakes centralized power distribution and power quality optimization tasks for regional power grids, effectively improving power supply stability and energy utilization efficiency. Additionally, it supports voltage matching and grid-connected power regulation for distributed new energy systems, undertakes power guarantee for municipal and industrial projects, and assists in old power grid renovation and capacity expansion, ensuring safe, efficient and economical operation of modern medium-voltage power distribution networks.
4. Main Application Scenarios
4.1 Urban & Rural Medium-Voltage Power Grid Construction
This 20KV 400V three-phase oil immersed transformer is widely applied in new urban power grid construction, old urban grid renovation and rural medium-voltage grid upgrading projects. The 20kV power supply system has a larger power supply radius and lower line loss, which perfectly solves the problems of insufficient capacity and high energy consumption of traditional 10kV power grids in urban and rural areas. It provides stable 400V three-phase power for residential communities, township public facilities and rural industrial zones, improving the overall power supply quality and reliability of regional civilian electricity.
4.2 Industrial Park & Manufacturing Base Power Supply
It is the preferred power distribution equipment for medium and large industrial parks, mechanical manufacturing bases, chemical factories, mining enterprises and processing workshops. Industrial three-phase equipment such as production lines, high-power motors and automated control systems requires stable 400V three-phase power support. The low-loss and high-stability performance of this three-phase oil immersed transformer can adapt to long-term full-load industrial operation and frequent load changes, ensuring continuous and stable production and avoiding economic losses caused by power supply instability.
4.3 Commercial & Public Infrastructure Power Distribution
Suitable for large shopping malls, office buildings, schools, hospitals, transportation hubs and other commercial and public service facilities. These scenarios have intensive three-phase power loads including central air conditioning, elevator systems, power distribution cabinets and public lighting systems. The 20KV 400V oil immersed distribution transformer provides continuous, safe and low-consumption power supply for public infrastructure, meeting the stable and continuous power consumption demand of commercial operation and public services.
4.4 Distributed New Energy Grid Connection Projects
As key supporting equipment for medium-sized photovoltaic power stations, wind farm power collection systems and regional energy storage power stations, this three-phase oil immersed transformer completes voltage conversion and grid-connected matching for new energy power generation. It stabilizes fluctuating electric energy generated by solar and wind power equipment, converts it into standard 400V power or grid-compliant voltage, reduces new energy transmission loss, and improves grid-connected efficiency and operational stability of distributed new energy projects.
4.5 Municipal Engineering & Large Temporary Power Projects
Thanks to strong environmental adaptability and reliable heavy-load operation performance, the transformer is widely used for long-term power guarantee of municipal infrastructure construction, urban renewal projects and large-scale outdoor temporary engineering. It can quickly build stable 20kV-level power distribution systems to provide safe and stable three-phase power support for field construction equipment, engineering facilities and temporary centralized power consumption scenarios.
5. Frequently Asked Questions (FAQ)
5.1 What are the advantages of 20KV 400V three-phase oil immersed transformers over traditional 10KV transformers?
Compared with conventional 10KV distribution transformers, 20KV 400V Three Phase Oil Immersed Transformers have multiple core advantages in modern power grid applications. The 20kV medium-voltage system features higher transmission voltage, smaller line current and lower long-distance transmission loss, effectively reducing line construction investment and improving power supply radius. This series of oil immersed transformers has higher insulation grade, stronger grid surge resistance and more stable operation in complex medium-voltage grid environments. Meanwhile, it supports larger load capacity and better adapts to urban and industrial power grid capacity expansion demands, making it the mainstream upgrade product for new-generation power grid construction.
5.2 What installation and environmental conditions are suitable for this oil immersed transformer?
This three-phase oil immersed distribution transformer supports dual installation modes of indoor substation placement and outdoor floor-mounted installation, adapting to most conventional power distribution scenarios. It operates stably in an ambient temperature range of -25℃ to +40℃ and altitude below 1000 meters, with excellent tolerance to high humidity, dust, wind and rain, and ultraviolet exposure. The fully sealed structure avoids waterlogging and moisture damage, suitable for outdoor open-air substations, industrial outdoor power distribution areas and rural field power stations. It only needs to avoid long-term severe chemical corrosion and continuous water immersion environments to ensure long-term stable operation.
5.3 What routine maintenance does the 20KV 400V three-phase oil immersed transformer require?
This fully sealed oil immersed transformer adopts maintenance-optimized design with low daily maintenance frequency. Users only need to conduct regular routine inspections: check the oil tank sealing condition to prevent insulating oil leakage, observe the operating temperature and voltage output stability, and inspect the tightness of line connections. It is necessary to keep the surrounding environment ventilated and dry, avoid long-term overload operation, and regularly clean surface dust and dirt. Professional staff should conduct periodic insulation performance testing and insulating oil quality inspection. Standard simple maintenance can effectively reduce failure rate, maintain low-energy-consumption operation, and extend the service life of the 20KV 400V three-phase oil immersed power transformer.
