500KVA to 2000KVA Three Phase Oil Immersed Power Transformers | 35KV Input, 220V/380V/440V Output
500KVA to 2000KVA Three Phase Oil Immersed Power Transformers | 35KV Input, 220V/380V/440V Output, 50Hz/60Hz Frequency
1. Product Description
This series covers commercial and industrial grade three phase oil immersed power transformers with continuous rated capacities ranging from 500KVA, 800KVA, 1000KVA, 1250KVA, 1600KVA up to 2000KVA, fully tailored for medium voltage power distribution and heavy-load industrial power conversion scenarios. Designed with a standard 35KV high voltage input, the oil type transformer delivers flexible low voltage output options including 220V single-phase, 380V three-phase and 440V international industrial voltage, perfectly adapting to both domestic civil power systems and overseas industrial power supply standards.
One of the core advantages of this 35KV oil immersed transformer series is its dual-frequency compatibility, supporting stable operation under both 50Hz and 60Hz grid frequencies. It eliminates frequency adaptation barriers for cross-regional power projects and international engineering construction. Manufactured in strict accordance with IEC 60076 international electrical standards and national power industry specifications, the equipment adopts high-quality low-loss silicon steel sheet core and high-purity copper winding structure, paired with mature ONAN oil natural air natural cooling system and fully sealed oil tank welding technology. This optimized structure effectively reduces no-load loss and load loss, solves heat accumulation and insulation aging problems during long-term full-load operation, and delivers far more stable performance than traditional conventional power transformers.
As a high-efficiency medium-and-large capacity oil filled distribution transformer, this product fills the market gap of 35KV high-voltage step-down equipment for medium and large industrial parks, municipal substations and infrastructure projects. The continuous capacity gradient from 500KVA to 2000KVA allows precise model selection according to actual project load demands, avoiding capacity waste or insufficient power supply, making it a mainstream upgrade solution for modern medium-voltage power grid transformation and industrial power distribution systems.
2. Core Product Purposes
The fundamental purpose of the 500KVA–2000KVA three phase oil immersed power transformer is to realize safe, stable and energy-efficient voltage step-down and electric energy distribution in 35KV medium-voltage power grids, building a reliable power transmission bridge between high-voltage overhead line systems and terminal low-voltage power consumption equipment.
In practical power system operation, this 35KV input oil transformer mainly undertakes hierarchical voltage conversion work. It steps down 35KV medium transmission voltage into standard 220V residential power, 380V general industrial power and 440V heavy industrial dedicated power, meeting the differentiated power demand of civil living, ordinary mechanical equipment and high-precision international industrial equipment. The dual 50Hz/60Hz frequency design ensures consistent power conversion accuracy and load capacity in different global power grid environments, greatly improving the universality of medium-voltage power transformation equipment.
Beyond basic voltage conversion, this low-loss oil immersed power transformer plays a key role in grid operation optimization and safety protection. It effectively suppresses grid voltage fluctuation, filters low-frequency harmonic interference, and reduces electric energy loss during power transmission and conversion. With excellent short-circuit resistance and overload tolerance, it can buffer instantaneous current surges caused by equipment startup and grid load peak changes, isolate circuit fault risks, and protect subsequent power distribution cabinets, electrical machinery and terminal equipment. It also balances regional power grid load, improves overall power supply stability, and supports long-term unattended operation of outdoor power facilities.
3. Typical Application Scenarios
3.1 Municipal & Rural 35KV Power Grid Substations
This 500KVA to 2000KVA oil immersed transformer series is widely deployed in urban and rural 35KV medium-voltage substations and power grid upgrading projects. The 500KVA and 800KVA models are suitable for township-level distribution stations and suburban community centralized power supply, providing stable 220V household electricity and 380V public facility power. The 1000KVA to 2000KVA large-capacity models are applied in urban hub substations to undertake regional peak load shunting, effectively improving the power supply capacity and reliability of municipal power grids, and solving the power shortage problem of rapidly developing urban areas.
3.2 Medium & Large Industrial Production Parks
It serves as core power transformation equipment for manufacturing parks, chemical plants, metallurgy bases, building material factories and other heavy industrial scenarios. Most industrial dedicated power grids adopt 35KV medium-voltage power supply, and industrial production lines require stable 380V three-phase power for mechanical operation, while high-precision imported equipment and international production lines need standard 440V voltage support. This multi-capacity oil type transformer can match different industrial load scales, adapt to 24-hour continuous full-load operation of industrial bases, and perfectly meet the comprehensive power demand of production equipment, workshop auxiliary facilities and office systems.
3.3 Overseas Engineering & International Industrial Projects
Thanks to its 50Hz/60Hz dual-frequency adaptation and 220V/380V/440V multi-voltage output capability, this three phase oil immersed power transformer is highly popular in overseas construction projects, cross-border industrial parks and international infrastructure engineering. It can fully adapt to 60Hz power grid standards in Europe, America, Southeast Asia and other regions, solving the problem of mismatched frequency and voltage of domestic equipment accessing overseas power systems, and providing stable and compliant power guarantee for overseas factory construction, municipal engineering and mining projects.
3.4 New Energy Station & Large Infrastructure Projects
The transformer series is also applicable to supporting power supply of photovoltaic power stations, wind power plants, energy storage power stations, highway infrastructure, railway transit supporting facilities and large commercial complex projects. New energy power generation projects mostly connect to 35KV medium-voltage grids, and this high-stability oil immersed transformer can stabilize fluctuating new energy power output, complete efficient voltage conversion, and meet on-site operation power consumption and grid-connected power transmission requirements. For large public infrastructure with large power consumption and high stability requirements, its strong load resistance and anti-interference performance ensure zero-failure continuous power supply.
4. Core Product Features
4.1 Complete Capacity Gradient & Flexible Voltage Adaptation
Covering 500KVA to 2000KVA full-range mainstream industrial capacities, this 35KV oil immersed power transformer supports three low-voltage output specifications of 220V, 380V and 440V, covering all common civil and industrial voltage demands. The unified 35KV high-voltage input design adapts to mainstream medium-voltage grid standards worldwide. Users can select the exact capacity and voltage configuration according to project load, grid parameters and equipment standards, eliminating equipment adaptation limitations and improving project matching accuracy.
4.2 Dual-Frequency Universal Operation (50Hz/60Hz)
Different from conventional single-frequency transformers, this three-phase oil filled transformer adopts optimized electromagnetic winding design, which can maintain stable magnetic circuit operation under both 50Hz and 60Hz grid frequencies without core overheating, efficiency attenuation or voltage deviation. It realizes free switching of global mainstream power frequency standards, greatly reducing equipment customization costs for cross-regional and international projects, and improving the universal applicability of medium-voltage power transformation equipment.
4.3 Ultra-Low Loss & High Energy-Saving Performance
Adopting high-grade low-loss oriented silicon steel sheet core and precision layered copper winding process, the equipment effectively minimizes no-load loss, load loss and magnetizing current. Compared with traditional old-fashioned transformers, the overall energy consumption is reduced by more than 20%, and the power conversion efficiency remains above 98% under long-term partial load and full-load operation. The optimized magnetic circuit structure avoids magnetic flux leakage, ensuring long-term efficient and stable operation, and effectively reducing daily power consumption and operation costs for power grids and industrial enterprises.
4.4 Excellent Environmental Adaptability & Long Service Life
Equipped with fully sealed welded oil tank and standard ONAN natural cooling system, the whole machine has excellent waterproof, dustproof and moisture-proof capabilities. The external shell adopts weather-resistant and anti-corrosion coating, which can resist ultraviolet radiation, rain erosion, high temperature exposure and low temperature freezing, adapting to outdoor open-air substations, dusty industrial sites and humid coastal environments. The high-purity insulating oil maintains stable dielectric insulation and heat dissipation performance for a long time, delaying internal component aging and extending the overall service life of the transformer.
4.5 Strong Safety Stability & Fault Resistance
The internal winding adopts integral fastening and multi-layer composite insulation structure, with strong mechanical stability and short-circuit impact resistance, which can effectively resist instantaneous short-circuit current and grid voltage surge damage. Standard equipped with pressure relief valve, oil level monitoring gauge and temperature sensing protection device, it can automatically release internal overpressure and monitor operating status in real time, avoiding equipment burnout and safety accidents caused by overheating and overpressure. The low partial discharge design ensures safe and reliable long-term operation under 35KV high-voltage working conditions.
4.6 Low Maintenance & High Comprehensive Cost Performance
This industrial-grade oil immersed power transformer has a mature and simplified internal structure without fragile electronic components, with extremely low daily failure rate. The fully sealed design avoids frequent oil replacement and internal cleaning, and daily maintenance only requires regular oil quality inspection, oil level calibration and sealing performance check. It supports long-term unattended outdoor operation, greatly saving later operation and maintenance manpower and material costs. With complete specifications, flexible matching and durable performance, it has outstanding comprehensive cost performance in medium and large power distribution projects.
5. Frequently Asked Questions (FAQ)
Q1: How to choose the correct capacity from 500KVA to 2000KVA for 35KV transformer projects?
Capacity selection mainly depends on actual operating load and future expansion reserve. The 500KVA and 800KVA models are suitable for small industrial parks, township substations and single factory zones with stable and relatively low power load. The 1000KVA and 1250KVA are the most versatile specifications, ideal for most municipal distribution stations and medium-sized manufacturing enterprises. The 1600KVA and 2000KVA high-capacity models are recommended for large industrial bases, comprehensive commercial parks and hub substations with large peak power consumption. It is suggested to reserve 10%–20% capacity margin during selection to cope with subsequent equipment expansion and load growth.
Q2: What is the application difference between 220V, 380V and 440V output voltages?
The three output voltages correspond to different terminal power consumption scenarios. 220V output is mainly used for single-phase civil facilities such as residential lighting, office equipment and daily living electricity. 380V three-phase voltage is the mainstream power supply for domestic industrial mechanical equipment, workshop production lines and public power distribution systems. 440V voltage is specially designed for overseas industrial equipment, imported high-precision machinery and international standard production lines, matching 60Hz overseas power grid standards. Users can freely combine output voltages according to on-site mixed power demand of civil and industrial equipment.
Q3: What daily maintenance work is required for outdoor installed 35KV 50Hz/60Hz oil immersed transformers?
Daily maintenance focuses on three core items to ensure long-term stable operation. First, regularly inspect the oil tank welding seams, sealing gaskets and radiator parts to eliminate hidden dangers of insulating oil leakage, and check the oil level and clarity to replace deteriorated and turbid oil in time. Second, clean the surface dust and sundries of the heat dissipation structure regularly to ensure unobstructed natural heat dissipation and prevent equipment overheating under high-load operation. Third, periodically test the insulation resistance of high and low voltage windings and verify voltage and frequency output stability, check the integrity of safety protection devices, and troubleshoot abnormal noise and temperature rise to avoid equipment failure and grid operation risks.
