20mva 25mva 110kv 33kv Step Down Toroidal Oil Immersed Power Transformer
20mva 25mva 110kv 33kv Step Down Toroidal Oil Immersed Power Transformer
1. Product Description
The 20MVA 25MVA 110kV 33kV step down toroidal oil immersed power transformer is a high-capacity, high-voltage power conversion device customized for medium and large power grid transmission and industrial power supply systems. Adopting advanced toroidal core winding technology different from traditional laminated core transformers, this oil immersed power transformer features a closed annular magnetic circuit structure, which effectively solves the problems of magnetic leakage and high energy loss of conventional power transformers. With two mainstream capacity specifications of 20MVA and 25MVA and a standard 110kV to 33kV step-down voltage ratio, this high voltage step down transformer is a core piece of equipment for secondary voltage reduction in regional power grids, industrial power stations and new energy centralized power generation bases. All products are manufactured in full compliance with IEC 60076 international power transformer standards and national grid operation specifications, adopting full oil-immersed sealed cooling and insulation design. The integral welded oil tank and high-purity transformer insulating oil ensure stable internal operating environment, while the precise toroidal coil layout greatly improves voltage conversion accuracy and operational stability. This 110kV/33kV toroidal oil immersed transformer supports long-term full-load and overload intermittent operation, adapting to complex and variable power load demands of large-scale power consumption scenarios.
2. Core Purpose
This high-power toroidal oil immersed power transformer mainly undertakes high-precision voltage step-down, power transmission distribution and grid operation stabilization in high-voltage power systems. Its core function is to convert 110kV high-voltage transmission grid power into 33kV medium-voltage usable power, providing standardized and stable power supply for downstream medium-voltage distribution networks, large industrial enterprises and new energy power collection systems. Compared with ordinary core transformers, the toroidal structure effectively optimizes three-phase current balance, suppresses grid harmonic interference, voltage surge and power fluctuation, and significantly improves the overall power supply quality of the power system. As a key intermediate link in power transmission and distribution, the 20MVA and 25MVA step down power transformer reduces power transmission loss during voltage conversion, realizes efficient energy utilization, and provides reliable overload protection and fault isolation for downstream power equipment. It can also adapt to peak load adjustment of regional power grids, balance power supply and demand, and ensure the safety and continuity of large-scale power supply operation.
3. Application Scenarios
3.1 Regional Power Grid Substations
This 110kV 33kV step down toroidal oil immersed power transformer is widely used in urban regional main substations, county-level power distribution hubs and rural large-scale grid upgrading projects. It serves as the core step-down equipment for high-voltage power transmission, converting 110kV long-distance transmission power into 33kV medium-voltage power for secondary distribution, covering power supply demands of urban construction, residential clusters and regional public facilities.
3.2 Large Industrial and Mining Enterprises
It is the preferred power conversion equipment for large steel plants, chemical enterprises, mining groups, metallurgical factories and heavy manufacturing bases. The 20MVA and 25MVA high-capacity models fully meet the long-term high-load power demand of industrial production lines, large mechanical equipment and mining power systems. The stable output and strong anti-interference capability of the toroidal oil immersed transformer ensure the continuous and safe operation of industrial high-power equipment.
3.3 New Energy Power Generation Projects
The transformer is perfectly matched for centralized power distribution and grid connection of large-scale photovoltaic power stations, onshore and offshore wind farms, and energy storage power stations. It collects and steps down high-voltage power generated by new energy units, solves the problems of unstable voltage and irregular power output of new energy power generation, and realizes efficient and safe grid-connected power transmission.
3.4 Transportation and Infrastructure Projects
It is also applicable to supporting power supply of large railway hubs, highway transportation centers, port terminals and urban comprehensive infrastructure projects. The high stability and strong environmental adaptability of the oil immersed step down power transformer can cope with continuous high-power operation demands of public infrastructure, avoiding power supply faults that affect regional operational efficiency.
4. Product Features
4.1 Advanced Toroidal Core Structure, Ultra-Low Loss
Different from traditional transformers with open magnetic circuits, this toroidal oil immersed power transformer adopts a fully closed annular magnetic core design, with no magnetic dead angle and extremely low magnetic leakage. The optimized magnetic circuit structure greatly reduces no-load loss, load loss and excitation current, and the overall energy consumption is far lower than that of conventional transformers of the same capacity. It can effectively reduce long-term grid operation and industrial power consumption costs, with prominent energy-saving and emission-reduction effects.
4.2 High Voltage Resistance and Super Stable Operation
Designed for 110kV high-voltage grade operation, the equipment is equipped with high-strength composite insulating materials and multi-layer winding insulation protection structure. Combined with professional oil-immersed insulation technology, it has excellent high-voltage breakdown resistance and electrical aging resistance. The toroidal coil ensures uniform and stable internal voltage bearing, effectively suppresses voltage fluctuation and harmonic interference, and maintains precise and consistent voltage step-down output during long-term full-load operation.
4.3 Excellent Oil Immersed Heat Dissipation System
Adopting mature ONAN/ONAF oil natural circulation cooling mode, the internal high-purity transformer oil forms a circulating heat dissipation system, which quickly takes away heat generated by core and winding operation. Equipped with external high-efficiency heat dissipation fins, it realizes passive rapid heat exchange with the outside air. This stable oil cooling structure avoids local overheating of the equipment, supports 24-hour uninterrupted high-load operation, and greatly improves operational safety and stability.
4.4 Fully Sealed Structure, Strong Environmental Adaptability
The whole machine adopts integral fully sealed welding oil tank technology, which completely isolates internal components from external moisture, dust and corrosive gases. It effectively prevents insulating oil deterioration, internal winding corrosion and insulation aging. The outdoor-grade anti-corrosion and weather-resistant shell can adapt to harsh working environments such as high temperature, low temperature, humidity and dust, and is suitable for outdoor substation open-air installation and long-term unattended operation.
4.5 Compact Structure and High Power Density
The toroidal core structure features smaller volume and lighter weight under the same power rating, with higher power density than traditional transformers. The compact overall layout saves substation installation space, reduces infrastructure construction cost, and supports flexible installation and rapid commissioning of large power grid projects.
4.6 Low Noise and High Operational Safety
The closed toroidal magnetic circuit effectively reduces electromagnetic vibration and operating noise during equipment operation, realizing low-noise environmental-friendly operation. Equipped with overvoltage, overcurrent and overload protection devices, the transformer can automatically isolate faults in case of abnormal grid load, effectively protecting downstream power equipment and grid system safety.
5. FAQ
5.1 What is the application difference between 20MVA and 25MVA 110kV/33kV toroidal oil immersed transformers?
The two models are consistent in structural design and working principle, and the main difference lies in maximum bearing load and applicable scenarios. The 20MVA step down toroidal power transformer is suitable for regional small and medium-sized substations, conventional industrial parks and medium-scale new energy power stations with stable and conventional power load, which can fully meet daily operating power demand with reasonable load margin. The 25MVA high-capacity model is more suitable for large industrial and mining enterprises, regional core power grid hubs and large-scale wind and solar power generation bases with large instantaneous load and future power expansion plans. Users can select the model according to the actual peak load of the project and long-term capacity expansion requirements.
5.2 Why is toroidal structure better than traditional core structure for high voltage oil immersed transformers?
Traditional laminated core transformers have open magnetic circuits with obvious magnetic leakage, resulting in high no-load loss, large operating noise and unstable voltage output. The toroidal oil immersed power transformer adopts a fully closed annular magnetic core, which eliminates magnetic leakage fundamentally, reduces overall energy loss by more than 20% compared with traditional models, and achieves higher voltage conversion accuracy. Meanwhile, its uniform magnetic field distribution avoids local overheating of windings, improves equipment operation stability and service life, and is more suitable for long-term high-load operation of 110kV high-voltage power systems.
5.3 What are the key maintenance points for 110kV to 33kV high voltage oil immersed transformers?
Daily maintenance of this high-power step down transformer is standardized and manageable. First, regularly inspect the oil level, color and cleanliness of the insulating oil, replace aging and deteriorated transformer oil regularly to ensure heat dissipation and insulation performance. Second, check the sealing performance of the oil tank and connecting parts quarterly to prevent oil leakage and moisture ingress. Third, clean the dust and dirt on the surface of heat dissipation fins to avoid blocking heat dissipation and causing high-temperature overload operation. In addition, conduct regular electrical performance tests on winding insulation resistance and voltage conversion accuracy to eliminate potential faults in advance and ensure long-term stable grid operation.
