20KV 400V 800kVA 1000kVA 1250kVA Oil Immersed Distribution Transformers
1. Product Overview
The 20KV 400V 800kVA 1000kVA 1250kVA Oil Immersed Distribution Transformers are high-efficiency, low-loss medium-capacity three-phase power distribution equipment engineered for modern medium-voltage power grid systems. Designed with a standard 20kV high-voltage input and 400V low-voltage output ratio, this transformer series covers three mainstream industrial and municipal capacity specifications: 800kVA, 1000kVA and 1250kVA. Manufactured in full compliance with IEC 60076 international standards and global power distribution industry norms, these oil immersed distribution transformers adopt fully sealed oil cooling technology and optimized core winding structure, serving as core voltage conversion and power distribution devices for 20kV medium-voltage power systems.
As upgraded energy-saving distribution transformers, this product line effectively solves the voltage matching problem between 20kV overhead transmission lines and 400V low-voltage terminal loads. The graded capacity design seamlessly covers medium-load power supply demands from industrial parks, urban substations to rural grid upgrading projects. Compared with traditional ordinary transformers, these 20kV 400V oil immersed transformers feature lower no-load and load loss, stronger overload resistance and more stable three-phase voltage balance performance. Widely applicable for indoor substation and outdoor floor-mounted installation, they have become the most popular medium-capacity power transformation solution for modern urban and rural power grid construction, industrial power supply and commercial power distribution projects.
2. Core Product Features
2.1 Standard 20kV to 400V Voltage Conversion & Precise Regulation
This series of oil immersed distribution transformers adopts a professional 20kV/0.4kV voltage transformation ratio, accurately converting medium-voltage grid electricity into standard 400V three-phase industrial and civilian power. Equipped with a reliable off-circuit tap changer, the equipment supports precise voltage adjustment within a reasonable range, effectively compensating for long-distance transmission voltage drop and grid voltage fluctuation caused by peak load changes. The strict symmetrical winding structure ensures balanced three-phase voltage and current output, minimizes three-phase unbalanced loss, and maintains ultra-low voltage deviation during long-term operation, greatly improving terminal power supply quality and grid operational stability.
2.2 Graded Capacity Matching for Diversified Medium-Load Scenarios
Covering 800kVA, 1000kVA and 1250kVA three core capacity grades, this 20kV oil immersed transformer series achieves full coverage of mainstream medium-capacity power distribution demands. The 800kVA oil immersed distribution transformer is compact and energy-saving, suitable for small industrial zones, township centralized power supply and ordinary commercial cluster load demands. The 1000kVA model is a universal mainstream specification with balanced load capacity and energy consumption, widely used in urban community power distribution and standard factory power supply. The upgraded 1250kVA high-load transformer enhances overload resistance and continuous power supply capacity, perfectly adapting to medium-sized industrial parks and peak-intensive power consumption scenarios, meeting diversified hierarchical power supply requirements.
2.3 Low-Loss Energy-Saving Structure & High Power Efficiency
Adopting high-quality high-permeability grain-oriented silicon steel core and high-purity oxygen-free copper windings, these 20kV 400V distribution transformers greatly reduce no-load loss, load loss and magnetic leakage loss. The optimized magnetic circuit and winding layout eliminate redundant energy consumption, achieving industry-leading energy-saving indicators. Compared with conventional old-generation transformers, the new structural design effectively lowers long-term operating power consumption, reduces grid operation costs and carbon emissions, and fully meets modern energy-saving and low-carbon power grid construction standards. The stable power transmission efficiency ensures long-term full-load and intermittent overload operation without excessive heat generation and power attenuation.
2.4 Fully Sealed Oil Immersed Cooling & Superb Durability
Featuring a fully sealed corrugated oil tank structure and advanced oil immersed natural circulation cooling system, the transformer uses high-purity insulating mineral oil as heat dissipation and insulation medium. The circulating oil flow rapidly absorbs and dissipates internal operating heat, realizing efficient and stable temperature control under continuous full-load operation. The fully sealed design completely isolates internal windings and iron core from external air, moisture and dust, preventing insulating oil aging, oxidation and moisture absorption. This structure avoids insulation performance degradation and internal short-circuit faults, significantly extending the service life of the equipment and reducing daily maintenance frequency and operational costs.
2.5 Strong Environmental Adaptability & Comprehensive Safety Protection
Designed for dual indoor and outdoor installation, the 800kVA/1000kVA/1250kVA oil immersed distribution transformers adopt anti-corrosion, weather-resistant and anti-aging shell coating, adapting to ambient temperatures from -25℃ to +40℃ and harsh environments such as high humidity, dust and outdoor ultraviolet exposure. Equipped with multiple safety protection mechanisms including over-current protection, short-circuit protection, over-temperature protection and pressure relief protection, the equipment can quickly respond to grid surge, sudden load surge and circuit faults to cut off risks. It has strong short-circuit withstand capability and operational stability, realizing long-term unattended safe operation for power distribution systems.
3. Core Uses
The 20KV 400V 800kVA 1000kVA 1250kVA Oil Immersed Distribution Transformer is dedicated to medium-voltage power conversion, grid voltage stabilization and safe power distribution in urban, rural and industrial three-phase power systems. Its core function is to step down 20kV medium-voltage electric energy from transmission grids to standard 400V low-voltage power, realizing safe voltage matching between medium-voltage power grids and terminal industrial, commercial and civilian electrical equipment.
In actual power system operation, this energy-saving oil immersed transformer optimizes power quality, suppresses grid harmonic interference and voltage fluctuation, and reduces medium and short-distance power transmission loss. It undertakes classified medium-load power supply tasks through different capacity configurations: the 800kVA specification meets conventional medium-load daily power consumption, the 1000kVA model adapts to universal standardized power distribution demands, and the 1250kVA high-capacity version supports intensive peak power consumption and continuous heavy-load operation. In addition, it can be used for new energy grid-connected voltage matching, power grid capacity expansion and old grid renovation, effectively improving the reliability, stability and energy utilization rate of regional power distribution networks.
4. Main Application Scenarios
4.1 Urban & Rural Power Grid Upgrading and Distribution
This series of 20kV 400V oil immersed distribution transformers is the core equipment for modern urban power grid reconstruction, rural medium-voltage grid upgrading and township power station construction. The 800kVA and 1000kVA models are widely used in urban residential clusters, township central areas and rural industrial zones, solving the problems of insufficient power supply capacity and voltage instability of old power grids. The 1250kVA transformer is applied to urban new districts and key rural development zones to meet the growing peak power consumption demand of residents and small industries, optimizing regional power grid structure and improving civil power supply quality.
4.2 Industrial Park & Manufacturing Base Power Supply
It is perfectly suitable for medium-sized industrial parks, light manufacturing bases, mechanical processing factories and mining auxiliary power supply scenarios. Industrial production lines, three-phase motors and automated equipment require stable 400V three-phase power supply. The 1000kVA and 1250kVA oil immersed distribution transformers can bear long-term continuous medium and heavy industrial loads, adapt to frequent load fluctuations in industrial production, ensure stable operation of production equipment, and avoid production shutdown and equipment damage caused by power quality problems.
4.3 Commercial & Public Infrastructure Power Distribution
Widely applied in large shopping malls, office buildings, schools, hospitals, transportation hubs and other commercial and public facilities. These scenarios have stable and intensive three-phase power loads such as central air conditioning, elevator systems and power distribution cabinets. The low-loss and high-stability performance of the 20kV oil immersed transformer series provides continuous and safe 400V power guarantee for public facilities, reduces daily power loss, and ensures the stable operation of public service and commercial operation systems.
4.4 Distributed New Energy Grid Connection Projects
Serving as key supporting equipment for medium-sized photovoltaic power stations, wind farm power collection systems and regional energy storage power stations. The 20kV/400V oil immersed distribution transformer stabilizes fluctuating electric energy generated by new energy equipment, completes accurate voltage conversion and safe grid-connected matching, reduces new energy power transmission loss, and improves the overall grid-connected efficiency and operational stability of distributed new energy projects.
4.5 Municipal Engineering & Large Temporary Power Projects
Applicable for long-term power guarantee of municipal infrastructure, urban renovation projects and large-scale outdoor temporary engineering. With strong environmental adaptability and large load capacity, the 800kVA to 1250kVA transformer series can quickly build stable medium-voltage power distribution systems, providing reliable power support for municipal engineering construction, field operation equipment and temporary centralized power consumption scenarios.
5. Frequently Asked Questions (FAQ)
5.1 How to select capacity from 800kVA, 1000kVA and 1250kVA for 20kV 400V oil immersed transformers?
Capacity selection depends on actual load demand, peak power consumption and application scenarios. The 800kVA oil immersed distribution transformer is ideal for small industrial workshops, ordinary township power supply and small commercial clusters with stable medium loads and low peak fluctuation. The 1000kVA 20kV 400V transformer is the most cost-effective universal model, suitable for most urban residential communities, standard industrial parks and public facility power distribution projects. The 1250kVA high-capacity oil immersed transformer is recommended for scenarios with intensive peak power consumption, medium-sized industrial production lines and regional grid capacity expansion. It is suggested to reserve 10%-20% load margin to avoid long-term full-load operation and extend equipment service life.
5.2 What are the core advantages of 20kV 400V oil immersed distribution transformers compared with 10kV transformers?
Compared with traditional 10kV distribution transformers, 20kV oil immersed distribution transformers have obvious technical and operational advantages. The 20kV medium-voltage grid has higher transmission voltage, lower line current and smaller long-distance transmission loss, which is more suitable for large-area regional power supply. This series of transformers features higher insulation level, stronger grid surge resistance and more stable operation in medium-voltage power systems. In addition, the 20kV power distribution system saves line investment, improves power supply radius and grid capacity, and better meets the capacity expansion demand of modern urban and industrial power grids, becoming the mainstream upgrade choice for new power grid construction.
5.3 What are the daily maintenance and operating requirements for this oil immersed transformer series?
The 800kVA/1000kVA/1250kVA fully sealed oil immersed distribution transformers feature low maintenance design, but standardized daily inspection is required for long-term stable operation. The equipment adapts to indoor ventilation and outdoor floor-mounted installation, avoiding long-term waterlogging, severe corrosion and over-temperature environments. Users need to regularly check the oil tank sealing performance to prevent oil leakage, observe insulating oil quality and temperature changes, and inspect line connection tightness and terminal voltage stability. Regular dust cleaning and insulation performance detection can effectively reduce failure rate, maintain low-energy-consumption operation state, and ensure long-term safe and stable operation of the 20kV 400V power distribution transformer.
