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In data centers, how does short-circuit impedance affect transformer performance?   In data center power systems, power quality and system protection are paramount for business continuity. Short-circuit impedance, a critical yet often overlooked transformer parameter, directly impacts a transformer's ability to withstand fault conditions and maintain system stability. This is especially vital in large-scale, mission-critical data center environments. At HENTG POWER, we go beyond standard specifications by deeply optimizing short-circuit impedance. Our designs strike a precise balance between system protection and operational efficiency, minimizing equipment damage risk and ensuring seamless, uninterrupted power. Our Core Differentiators and Selling Points: 1. Scenario-Based Custom Impedance DesignWe do not offer a one-size-fits-all solution. Instead, we provide customized short-circuit impedance designs based on your data center's specific load profile, distribution architecture, and protection coordination requirements. Our approach ensures that during a fault, the transformer not only limits fault current effectively but also maintains busbar voltage stability, protecting sensitive IT equipment from damaging voltage dips. 2. Precision Engineering with Superior MaterialsOur transformers feature windings with high mechanical strength and graded insulation, combined with low-loss grain-oriented silicon steel cores. This construction significantly enhances short-circuit withstand capability, reduces stray losses and hot-spot temperatures, and ensures long-term electrical stability and longevity, even under stressful fault conditions. 3. Intelligent, Integrated Protection SystemsOur transformers are equipped with multi-dimensional monitoring interfaces and are designed for seamless integration with your data center's power management system. By analyzing real-time data on current and temperature in the context of the transformer's impedance characteristics, our systems enable predictive fault awareness and selective coordination, preventing nuisance tripping and drastically reducing fault recovery time. 4. Uncompromising Efficiency and Global System CompatibilityWhile safety is our priority, we never sacrifice performance. Our optimized impedance design helps dampen harmonic resonance, reducing both no-load and load losses to support your data center's green energy initiatives. Furthermore, our transformers are engineered to be compatible with various grounding systems and operational modes, meeting diverse global grid standards and redundancy configurations. Choose HENTG POWER for transformers that deliver enhanced system protection, extended equipment lifespan, and unwavering operational stability under all conditions. At HENTG POWER, we are committed to engineering transformer solutions that deliver high performance, superior stability, and robust security for modern data centers, ensuring your critical operations remain uninterrupted and efficient.

As key equipment in the distribution segment of the North American power grid, the design, manufacturing, and testing of American-style pad-mounted transformers adhere to a mature and stringent system of standards. Compliant products are a prerequisite for ensuring the safety, reliability, and efficiency of the grid. The following three standards form the cornerstone of their compliance:   ANSI C57.12.00 - The Foundation for General Performance and Testing   Core Content: This standard serves as the fundamental general specification for all liquid-immersed distribution transformers. It stipulates transformer ratings (e.g., capacity, voltage), test procedures (including induced voltage tests, lightning impulse tests), temperature rise limits, insulation classes, and operating performance.   Why It Matters: It ensures the basic electrical performance and mechanical reliability of the transformer as power equipment, providing the underlying guarantee for product interchangeability and safe operation.   ANSI C57.12.34 - Key to Specific Construction and Safety   Core Content: This is the structural standard specifically for American-style pad-mounted transformers. It details requirements for the mechanical strength of the enclosure, corrosion-resistant coatings, thermal design, protection class (e.g., IP Code), safety design of high-voltage and low-voltage cable compartments (e.g., tamper-resistance, protection against accidental contact), and installation interfaces.   Why It Matters: This standard ensures that the pad-mounted transformer, when installed outdoors at ground level, can withstand environmental impacts, protect internal components, and maximize safety for both operators and the public.   DOE 10 CFR Part 431 (2016) - The Mandatory Energy Efficiency Threshold   Core Content: This is a federal mandatory regulation issued by the U.S. Department of Energy (DOE), defining the minimum energy efficiency levels that distribution transformers must achieve. The 2016 standard significantly raised efficiency requirements, aiming to reduce transformer no-load losses and load losses.   Why It Matters: Compliance with the DOE 2016 standard is a mandatory legal requirement for products to enter the U.S. market. It relates not only to operational costs but also demonstrates regulatory compliance and corporate social responsibility (reducing carbon emissions).   Integrated Conclusion: How to Ensure Compliance?   A truly North American market-compliant American-style pad-mounted transformer must simultaneously meet all three standards above.   ANSI C57.12.00 ensures it is a "qualified transformer."   ANSI C57.12.34 ensures it is a "safe and structurally sound pad-mounted enclosure."   DOE 2016 ensures it is a "modern, energy-efficient device legally salable in the United States."   When procuring or inspecting, clearly request and require proof of compliance with these standards from your supplier, such as:   Standard designations and efficiency values clearly marked on the product nameplate.   Third-party certification reports issued by recognized bodies like the Canadian Standards Association (CSA).   At HENTG Power, our American-style pad-mounted transformer products are designed from the ground up in strict accordance with the structural and performance specifications of ANSI C57.12.00 and C57.12.34. We not only meet the mandatory DOE 2016 energy efficiency requirements but are also committed to providing high-efficiency products that exceed standards through optimized design and advanced materials, directly reducing your total cost of ownership. If you are looking for a fully North American standard-compliant, reliable, and competitively priced American-style pad-mounted transformer for your project, HENTG Power is your trusted partner.

The key lies in transformer optimization.   In modern data center operations, transformers rarely operate at full load. Industry data shows that most data center transformers typically operate between 30% and 70% of their rated load. This partial load operation mode makes the transformer's partial load efficiency a key factor directly impacting energy costs and PUE (Power Usage Effectiveness), thus determining the overall energy efficiency performance of the data center.   HENTG Power focuses on designing and manufacturing transformer solutions that maintain high performance and low losses under partial load conditions. Our expertise helps data centers worldwide achieve energy stability, superior efficiency, and long-term operational sustainability.   Four Core Technologies for Achieving High Efficiency Under Partial Load   1. Optimized Core Design We use top-quality, low-loss silicon steel sheets, combined with precisely controlled magnetic flux density parameters. This innovative design minimizes core losses, ensuring the transformer maintains efficient and stable operation even with dynamic load changes, significantly improving energy efficiency under partial load.   2. Advanced Winding Structure HENTG's windings employ a patented balanced, segmented, compact layout, effectively reducing load losses and optimizing current distribution. This design enables our transformers to maintain exceptionally stable performance during load fluctuations, making them particularly suitable for the ever-changing power demands of modern data centers.   3. Low No-Load Loss Technology Through precision core lamination technology and innovative stepped lap joint assembly technology, we have successfully reduced no-load losses to industry-leading levels. This means that the transformer consumes extremely low power under light load or standby conditions, saving significant basic energy consumption for data centers.   4. Enhanced Heat Dissipation and Insulation Performance We have designed a highly efficient ventilation channel system and used high-temperature resistant insulation materials, significantly improving heat dissipation efficiency. Even in the harsh environment of 24/7 data center operation, this ensures stable equipment operation and significantly extends equipment lifespan.   Why Choose HENTG Power's High-Efficiency Transformers? Choosing transformers optimized for partial load efficiency means:   Reduced energy waste – significantly lower operational carbon footprint   Lower operating costs – savings of up to 30% on transformer-related energy consumption   Improved system reliability – reduced overheating risk and extended equipment lifespan   Optimized PUE metrics – directly improved overall energy efficiency performance of the data center   At HENTG Power, we not only manufacture transformers, but we are committed to providing reliable, efficient, and future-proof power solutions for data centers worldwide. Our products are designed to meet the ever-increasing energy efficiency demands of modern data centers, helping customers maintain a competitive edge in the wave of digital transformation.

This is a very common misconception, but the answer is: more weight is not always better for a transformer. Weight is a design result, not a measure of performance. The weight of a transformer is determined by its design and performance, not by any specific target. While it primarily reflects the amount of materials used in manufacturing, this does not directly indicate the quality of its performance. Let's break down the reasons and conclusions from a few key aspects: Why do people have the illusion that the heavier, the better? Material reality: In the traditional concept, heavier electrical appliances often mean the use of more copper, iron and other metal materials, giving people a feeling of ‘full material’ and ‘strong and durable’. Cost correlation: Copper and silicon steel sheets constitute the primary components of transformers. Heavier transformers typically incur higher raw material costs, which naturally leads to the perception that ‘higher cost equals higher quality’. The key factor that determines the weight of the transformer The weight of the transformer mainly comes from two parts: the iron core (magnetic core) and the winding (coil). Iron core: usually made of silicon steel laminated, responsible for magnetic conduction and magnetic circuit. The larger and heavier the iron core, the greater the magnetic flux can be transmitted, and to a certain extent, it is allowed to carry more power. Winding: made of copper or aluminum wire, responsible for conducting electricity. The thicker the winding and the more turns, the heavier the weight, and the stronger the current carrying capacity and current shock resistance. What is the standard of ‘good’ transformer? The key indicators to evaluate the quality of a transformer are efficiency, temperature rise, reliability, voltage regulation rate, cost, etc. A good transformer is the best balance of these indicators under the premise of meeting the performance requirements. Why not the heavier the better? 1. Design and efficiency optimization (core reason) Modern transformer design is to achieve high efficiency, that is, the minimum loss in the process of energy conversion. Iron loss (no-load loss): It mainly occurs in the iron core and is directly related to the weight and material of the iron core. Blindly increasing the weight of the iron core may lead to an increase in iron loss and a decrease in efficiency. Copper loss (load loss) primarily occurs in the windings, which is related to the winding's resistance (i.e., the amount of copper used and its length). Although using thicker copper wire can reduce resistance, it also increases cost and weight. The optimal design is to find the best ratio of iron core and windings while meeting temperature rise and efficiency requirements. 2. Advancement of materials technology Core Materials: While conventional hot-rolled silicon steel sheets were previously used, modern transformers predominantly employ high-performing cold-rolled grain-oriented silicon steel sheets with superior magnetic conductivity and reduced losses, with amorphous alloy materials now being widely adopted. These advanced materials enable lower iron losses while maintaining reduced thickness and lighter weight. Transformers utilizing amorphous alloy cores can achieve 60%-70% lower no-load losses compared to traditional silicon steel counterparts, while retaining comparable or even lighter weight characteristics. Insulating materials: Better insulating materials allow the winding to operate safely at higher temperatures, thus reducing the amount of copper wire used while maintaining the life. 3. Application scenarios determine the standard of "good" Power transformers: Pursue extremely high efficiency and reliability. Their "good" is reflected in the lowest annual comprehensive energy consumption (iron loss + copper loss), not the largest weight. Electrical devices like chargers prioritize high power density, delivering substantial output in compact, lightweight designs. Here, 'lightweight and compact' are fundamental criteria for quality. A bulky, heavy phone charger would never be purchased. Audio transformer: The pursuit of extreme fidelity and frequency response characteristics, its design and materials (such as permalloy) are very special, weight and sound quality is not directly related. Conclusion The core of modern excellent transformers lies in "optimized design" and "advanced materials". Through scientific design and the use of high-performance materials (such as high-quality silicon steel sheets, amorphous alloys), lower losses, higher efficiency and better performance can be achieved with lighter weight. To judge the quality of a transformer, we should pay attention to its technical parameters, such as efficiency, loss, temperature rise, insulation grade, noise level, etc., rather than simply weighing its weight. In short, we should be looking for a "high performance" transformer, not a "heavy" transformer. The progress of technology is to achieve more powerful functions with less material and smaller volume.  

In industrial power distribution systems, dry-type transformers are the core hub connecting the high-voltage grid and electrical equipment. However, many people only consider capacity when purchasing transformers, overlooking the energy efficiency rating. The energy efficiency rating of a dry-type transformer measures its energy conversion efficiency and operating energy consumption. It is typically categorized into different levels and directly impacts operational losses, electricity costs, and environmental performance.

Medium and high voltage transformers are core equipment in the power transmission and distribution system, and their safe and stable operation directly affects the reliability of the power grid and the continuity of energy supply. Insulating oil, as a core component of transformers, plays a crucial role in insulation, heat dissipation, and arc extinguishing. For a long time, mineral insulating oil has dominated the market for medium and high voltage transformer insulating oil due to its mature preparation process and stable dielectric properties. However, with the increasing global environmental awareness and the advancement of the "dual carbon" target, the defects of mineral insulating oil, such as its non-renewable nature, low biodegradability, and low ignition point which easily lead to safety accidents, have become increasingly prominent, severely limiting its application in sensitive scenarios such as urban core areas, high-rise buildings, new energy power plants, and chemical industrial parks. Plant-based ester insulating oil, made from renewable vegetable oils, possesses natural advantages such as high ignition point, easy biodegradability, and environmental friendliness, making it an important alternative to medium and high voltage transformer insulating oil. In recent years, domestic and international academic and industrial circles have conducted extensive research and practice on the modification technology, compatibility optimization, and engineering applications of plant-based ester insulating oil. This white paper systematically reviews the current technological development status, core performance characteristics, application practices in medium and high voltage transformers, existing bottlenecks, and future trends of plant ester insulating oil. It aims to provide authoritative reference for the power industry, manufacturing enterprises, research institutions, and policy-making departments, and promote the large-scale and standardized application of plant ester insulating oil in the field of medium and high voltage transformers. I. Industry Overview and Development Background 1.1 Current Status of the Medium and High Voltage Transformer Insulating Oil Market Currently, the global medium and high voltage transformer insulating oil market is still dominated by mineral insulating oil, accounting for over 85% of the market. Mineral insulating oil is derived from petroleum refining, with mature technology and low cost, but it has significant shortcomings in terms of ecology and safety. According to statistics on power industry accidents, in the past five years, there have been over 100 soil and water pollution incidents caused by transformer oil leaks globally each year, with single pollution remediation costs reaching millions of yuan. At the same time, mineral insulating oil has a flash point of only 160-180℃, making it prone to overheating and fires under overload operation or equipment aging conditions, causing significant economic losses. With the rapid development of new energy power generation, wind power, photovoltaic, and other power plants are mostly located in ecologically sensitive areas, and urban power distribution networks are developing towards high density and compactness, continuously upgrading the requirements for the environmental protection and safety of transformer insulating oil. Against this backdrop, the market demand for environmentally friendly insulating oils such as plant-based ester insulating oils and synthetic ester insulating oils has been increasing year by year. Among them, plant-based ester insulating oils have seen particularly significant growth due to their renewable raw materials and relatively controllable production costs, with an average annual growth rate exceeding 15% in the global market size from 2020 to 2024. 1.2 Policy and Technology Drivers At the policy level, many countries have introduced environmental regulations to promote the upgrading of insulating oils. The EU's Waste Electrical and Electronic Equipment Directive and Regulation on Registration, Evaluation, Authorization and Restriction of Chemicals explicitly restrict the use of high-pollution insulating oils and require that electrical equipment prioritize the use of biodegradable insulating materials. China's "14th Five-Year Plan for Energy Conservation and Emission Reduction" and "Green and Low-Carbon Action Plan for the Power Industry" also encourage the promotion of environmentally friendly electrical equipment and supporting materials, providing policy support for the application of plant-based ester insulating oils. At the technological level, breakthroughs in vegetable oil refining and modification technologies have laid the foundation for the industrial application of plant-based ester insulating oils. Early plant ester insulating oils were difficult to adapt to medium and high voltage transformers due to their high viscosity and poor low-temperature fluidity. However, after modification treatments such as degumming, deacidification, hydrogenation, and transesterification, their key properties have been significantly improved, gradually meeting the long-term operation requirements of medium and high voltage transformers. Simultaneously, the optimization of transformer manufacturing processes has also provided the equipment conditions for adapting plant ester insulating oils. II. Preparation and Core Characteristics of Plant Ester Insulating Oils 2.1 Raw Materials and Preparation Process 2.1.1 Core Raw MaterialsThe raw materials for plant ester insulating oils are mainly renewable vegetable oils, with mainstream varieties including soybean oil, rapeseed oil, palm oil, and sunflower oil. Different raw materials have different properties and applicable scenarios. Rapeseed oil has a wide range of sources, a stable supply in Northwest and Southwest my country, and relatively low cost. Palm oil has a high saturated fatty acid content and outstanding thermal stability, but weak low-temperature performance, making it suitable for tropical and subtropical regions. Soybean oil has balanced dielectric properties and is one of the most widely used raw materials in commercial applications. In addition, non-edible vegetable oils such as jatropha oil and tung oil are gradually entering the research and development field, which can avoid competing with food crops for land and further improve the sustainability of raw materials. 2.1.2 Preparation and Modification Processes The basic preparation process of vegetable ester insulating oil includes raw material pretreatment, refining, modification, and finished product blending. Raw material pretreatment mainly removes impurities, moisture, and colloids from the oil; the refining process reduces the content of free fatty acids and harmful substances in the oil through steps such as deacidification, decolorization, and deodorization; the core modification process optimizes the performance of vegetable oils by addressing their inherent defects. Mainstream technologies include: Hydrogenation modification: Increasing the saturation of fatty acid chains through hydrogenation reactions improves oxidation stability, but the degree of hydrogenation must be controlled to avoid excessive hydrogenation leading to increased viscosity; Transesterification modification: Utilizing alcohols such as methanol and ethanol to undergo transesterification reactions with vegetable oils adjusts the molecular structure, reduces viscosity, and improves low-temperature fluidity; Composite modification: Combining hydrogenation and transesterification technologies to simultaneously optimize oxidation stability and low-temperature performance is currently the mainstream industrial modification solution. III. Application Practice of Vegetable Ester Insulating Oil in Medium and High Voltage Transformers 3.1 Application Scenario Adaptability AnalysisThe different application scenarios of medium and high voltage transformers impose different performance requirements on insulating oils. Vegetable ester insulating oil, with its safety and environmental protection advantages, demonstrates significant adaptability in the following core scenarios:Urban core areas and high-rise buildings: These scenarios are characterized by dense populations, concentrated equipment, and high risks and costs associated with fire and pollution. The high flash point of plant-based ester insulating oil eliminates the need for complex fireproofing and isolation facilities in transformers, reducing floor space and adapting to the compact layout of urban power distribution networks. New Energy Power Stations: Wind and photovoltaic power stations are often located in ecologically sensitive areas such as grasslands and mountains. The high biodegradability of plant-based ester insulating oil prevents oil leaks from damaging the ecological environment and is suitable for the frequent start-stop and large load fluctuations of new energy power stations. Chemical Industrial Parks and Mines: Chemical industrial parks contain flammable and explosive media, and mining environments are complex. The high safety of plant-based ester insulating oil reduces equipment operation risks and its strong resistance to pollution makes it suitable for harsh operating environments. Transmission in Sub-sea and Remote Areas: Transformers in sub-sea areas and distribution transformers in remote areas are difficult to maintain. The stability and environmental friendliness of plant-based ester insulating oil can reduce maintenance costs after leaks and improve equipment operation and maintenance efficiency. 3.2 Typical Application Cases at Home and Abroad 3.2.1 Domestic CaseA 220kV smart substation in a provincial power grid: Two transformers using soybean-based plant-based ester insulating oil were put into operation in 2022 and have been operating stably for over two years. Monitoring data shows that the transformer oil temperature was on average 3-5℃ lower than that of mineral oil transformers of the same capacity, the aging rate of the insulation paper was slowed down, and no abnormalities such as partial discharge were observed, making it suitable for the high-load operation requirements of substations. A 35kV box-type transformer at a large photovoltaic power station: This power station is located in a grassland ecological protection area. In 2023, a batch of transformers with palm-based modified vegetable ester insulating oil were replaced. During this period, one minor oil leak occurred. After natural degradation, no ecological abnormalities were observed in the soil of the leaked area, verifying its environmental advantages. 3.2.2 International Cases A 110kV distribution network in a German city: Starting in 2020, transformers in the city's core area were gradually replaced with rapeseed oil-based insulating oil. By 2024, over 50 units had been put into operation. The fire risk rate decreased by 80% compared to mineral oil transformers, and maintenance costs were reduced by 15%. A 66kV transformer in a US offshore wind power project: Utilizing composite modified vegetable ester insulating oil, suitable for the high humidity and high salt spray environment at sea, its dielectric performance remained stable over three years of operation, with no insulation degradation issues observed. 3.3 Equipment Adaptation and Adjustment in Application Vegetable ester insulating oil has a higher viscosity than mineral insulating oil. When used in medium and high voltage transformers, targeted adaptation and adjustment of the equipment are required to ensure operational efficiency: Heat dissipation system optimization: Increase the radiator area or upgrade the forced air cooling device to improve heat dissipation efficiency and avoid poor heat dissipation due to high viscosity; Sealing material adaptation: Vegetable esters can cause swelling of some rubber sealing materials, requiring replacement with ester-resistant materials such as fluororubber and silicone rubber to prevent oil leakage; Insulation structure adjustment: Optimize the winding insulation spacing design, taking advantage of the better match between the dielectric constant of vegetable esters and insulating paper, to further improve the reliability of the insulation system. IV. Existing Technical Bottlenecks and Challenges 4.1 Shortcomings in Core Technologies Insufficient Low-Temperature Performance: Most plant-based ester insulating oils crystallize or experience a sharp increase in viscosity below -20℃, affecting the low-temperature start-up and operation of transformers. This limits their promotion in high-latitude, cold regions. Oxidative Stability Needs Improvement: Unsaturated fatty acids in plant esters are prone to oxidation, generating acids, colloids, and other products that accelerate the aging of insulating paper and shorten transformer lifespan. While additives can mitigate this, long-term stability still needs verification. Large-Scale Production Process Needs Improvement: Consistency control in the modification process is difficult, resulting in significant performance fluctuations between different batches compared to mineral oils. Furthermore, the supply of high-purity raw materials is affected by agricultural production cycles, leading to insufficient stability. 4.2 Market and Cost Constraints Currently, the production cost of plant-based ester insulating oil is approximately 2-3 times that of mineral insulating oil. This higher cost slows its penetration rate in the medium- and high-voltage transformer market. In addition, while the supply chain for mineral insulating oil is mature, the supply chain systems for plant-based ester insulating oil, including raw material procurement, modification processing, warehousing, and transportation, are not yet fully mature, further hindering its large-scale promotion. 4.3 Lagging Standards and SpecificationsStandards for vegetable ester insulating oils, both domestically and internationally, remain incomplete. Current Chinese standards largely reference mineral oil standards, failing to fully reflect the characteristics of vegetable esters. While international standards include specific specifications, significant regional differences lead to insufficient product compatibility and mutual recognition, hindering cross-border applications and technical exchanges. Furthermore, operation and maintenance standards and aging assessment methods for vegetable ester insulating oil transformers are still in the exploratory stage, lacking unified guidance. V. Technological Optimization Directions and Solutions 5.1 Performance Optimization Technology Development Breakthroughs in novel modification technologies: Develop new technologies such as catalytic isomerization and genetic modification to adjust the molecular structure of vegetable esters, improving both oxidative stability and low-temperature performance. For example, isomerization reactions can convert unsaturated fatty acids into branched structures, lowering the freezing point to below -30℃. High-efficiency additive development: Develop specialized composite antioxidants and pour point depressants that can inhibit oxidation reactions and reduce negative impacts on insulating paper. Currently, nitrogen-containing heterocyclic antioxidants have demonstrated excellent synergistic antioxidant effects.Non-edible raw material development: Increase R&D efforts in non-edible plant oils such as hemp seed oil and Chinese pistache oil to reduce dependence on edible oils. Simultaneously, cultivate high-yield, high-purity specialty raw material crops through gene breeding technology. 5.2 Cost Control PathProcess cost reduction: Optimize and modify processes, simplify production flows, for example, by adopting continuous transesterification equipment to improve production efficiency; recycle by-products from the production process to reduce raw material loss.Supply chain integration: Establish an integrated supply chain encompassing raw material planting, processing, and production; sign long-term cooperation agreements with agricultural bases to stabilize raw material prices; promote regionalized production to reduce raw material transportation costs.Large-scale effect release: As market penetration increases, expand production scale to amortize R&D and equipment depreciation costs, gradually narrowing the price gap with mineral insulating oil. 5.3 Recommendations for Improving the Standards System Develop Specialized Standards: Based on the characteristics of plant-based ester insulating oils, develop specialized national standards covering raw materials, modification processes, core performance, and testing methods, clearly defining key indicators such as oxidation stability and low-temperature performance. Unify Operation and Maintenance Standards: Establish operation and maintenance standards for plant-based ester insulating oil transformers, including operation monitoring, aging assessment, and oil change cycles, to guide standardized operation and maintenance in the industry. Promote International Standard Recognition: Strengthen cooperation with organizations such as the International Electrotechnical Commission (IEC) to promote the coordination of domestic and international standards and enhance the international competitiveness of my country's plant-based ester insulating oil products. VI. Future Development Outlook 6.1 Technological Development TrendsIn the future, plant-based ester insulating oils will develop towards high performance, multifunctionality, and low cost. On the one hand, the integration of genetic engineering and novel modification technologies will achieve breakthrough improvements in the low-temperature performance and oxidation stability of plant esters, making them suitable for all regions and operating conditions. On the other hand, multifunctional composite plant-based ester insulating oils will become a research hotspot, such as products with insulation, thermal conductivity, and antibacterial functions, further expanding application scenarios. Furthermore, the combination of plant esters and nanomaterials is expected to achieve synergistic optimization of dielectric and heat dissipation performance. 6.2 Market Promotion Prospects With the continued tightening of environmental policies and the rapid development of new energy power, the market penetration rate of plant-based ester insulating oil in medium and high voltage transformers is expected to exceed 30% by 2030. Sub-sectors such as low-temperature products for high-latitude regions and customized products for new energy power plants will experience rapid growth. Simultaneously, as costs decrease, its application will gradually expand from high-end scenarios to ordinary power distribution networks, forming a large-scale promotion trend. 6.3 Industry Collaborative Development Recommendations Deep Industry-University-Research Collaboration: Encourage universities, research institutions, and enterprises to jointly tackle core technologies, establish pilot-scale production bases, and accelerate the transformation of technological achievements; Precise Policy Support: Recommend the introduction of subsidy policies to support the research and development and demonstration application of plant-based ester insulating oil, while including it in the green power equipment procurement list to guide market demand; Industry Exchange and Popularization: Strengthen technical exchange and promotion through industry exhibitions, technical seminars, and other forms to enhance the industry's understanding of plant-based ester insulating oil and promote the collaborative development of the entire industry chain. In conclusion, plant-based ester insulating oil, as an environmentally friendly and safe new type of insulating material, aligns with the green and low-carbon transformation of the power industry and has enormous application potential in medium and high-voltage transformers. Currently, although facing multiple challenges in technology, cost, and standards, with breakthroughs in modification technologies, improvements in the supply chain, and a sound policy framework, plant-based ester insulating oil will inevitably gradually replace mineral insulating oil and become the mainstream choice for insulating oil in medium and high-voltage transformers. The entire industry needs to work together to overcome technical difficulties, improve the industrial ecosystem, and jointly promote the power industry towards a safer, more environmentally friendly, and more sustainable development.

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These types of transformers are primarily regulated according to the following standards: ANSI C57.12.00: This standard is a general technical requirement standard for distribution transformers, covering basic specifications such as rated parameters, insulation class, temperature rise limits, test methods, and operating conditions. It serves as the foundation for the design of American-style prefabricated substations. ANSI C57.12.34: This standard specifically addresses the structural characteristics of prefabricated transformers, detailing their enclosure design, installation methods, protection levels (such as moisture-proof, insect-proof, and corrosion-proof requirements), operational safety, and wiring layout to ensure long-term stable operation of the equipment in outdoor environments. DOE 2016 Energy Efficiency Standard: The energy efficiency regulations implemented by the U.S. Department of Energy in 2016 impose higher efficiency requirements on distribution transformers, including limits on no-load and load losses. American-style prefabricated substations that meet this standard can significantly reduce operating energy consumption throughout their entire life cycle, meeting energy conservation and environmental protection regulatory requirements. In addition, American-style prefabricated substations typically need to comply with other relevant standards, such as the IEEE C57 series requirements for testing and maintenance, and NEMA's relevant structural standards, thus establishing a complete technical compliance system. Therefore, an American-style prefabricated substation that meets ANSI C57.12.00, C57.12.34, and DOE 2016 energy efficiency standards not only possesses excellent electrical performance and mechanical protection capabilities, but also meets the stringent energy efficiency and reliability requirements of the current US market, making it suitable for various commercial, industrial, and residential power distribution applications.

Dry-type transformers are required in complex buildings (basements, floors, rooftops, etc.) and crowded areas. Oil-immersed transformers are used in independent substations. Dry-type transformers are generally used for transformers within box-type substations. Oil-immersed transformers are generally used for temporary outdoor power supply. During construction, the choice between dry-type and oil-immersed transformers should be based on the available space. Oil-immersed transformers can be used for larger spaces, while dry-type transformers are preferred for more crowded areas.   Oil-immersed transformers are more suitable for areas with humid and hot climates. If dry-type transformers are used, they must be equipped with forced air cooling.   1. Appearance: Dry-type transformers have different packaging styles. The core and coils are visible in dry-type transformers, while only the outer casing is visible in oil-immersed transformers.   2. Different lead types: Dry-type transformers generally use silicone rubber bushings, while oil-immersed transformers mostly use porcelain bushings. 3. Differences in capacity and voltage: Dry-type transformers are generally used for power distribution, with capacities generally below 1600 kVA and voltages below 10 kV, though some are available up to 35 kV. Oil-type transformers, on the other hand, can cover a wide range of capacities and voltages, from small to large. China's currently under construction 1000 kV UHV test line exclusively utilizes oil-type transformers. 4. Differences in insulation and heat dissipation: Dry-type transformers are generally insulated with resin and cooled by natural air, with larger capacity transformers using fans. Oil-type transformers, on the other hand, rely on insulating oil for insulation, which circulates within the transformer to dissipate heat generated by the coils to the transformer's heat sink. 5. Applicable Locations: Dry-type transformers are mostly used in locations requiring fire and explosion protection, and are generally suitable for large and high-rise buildings. Oil-type transformers, however, are often used outdoors, where there is space for an emergency oil reservoir, as oil spills or leaks could cause fires in the event of an accident. Dry-type transformers are more suitable for indoor, environmentally friendly, and highly secure applications, while oil-immersed transformers are more suitable for outdoor, large-capacity, and long-term operation. When choosing the right transformer, consider power requirements, installation environment, budget, and ongoing maintenance capabilities to make the most appropriate decision.  

High-Level Overview: The Two Main SystemsAn oil-immersed transformer consists of two fundamental systems housed together: The Active Part (Core & Windings): The heart of the transformer, where electromagnetic induction and voltage transformation occur. The Tank and Cooling System: The body and life-support system, which provides insulation, cooling, and protection for the active part. relationships: 1. The Active Part (Core and Windings)This is the assembly that is lowered into the main tank. Core: Made from thin laminations of high-grade silicon steel (grain-oriented). The laminations are insulated from each other to reduce energy losses due to eddy currents. Function: Provides a low-reluctance path for the magnetic flux, linking the primary and secondary windings. Shape: Typically a closed core type (like a simple rectangle or "wound core") for better efficiency. Windings (Coils): These are conductors wound around the core limbs. There are always at least two sets: High Voltage (HV) and Low Voltage (LV). Conductor Material: Made of copper or aluminum, insulated with paper or enamel. Arrangement: The LV winding is placed closer to the core, with the HV winding wound concentrically outside it. This reduces the amount of insulation needed between the LV winding and the grounded core. Insulation: Key spacers and barriers made of pressboard and insulating paper are used to separate the windings from each other and from the core, and to provide mechanical stability. Tap Changer: A device that allows the number of turns in one of the windings (usually the HV) to be adjusted, thereby changing the voltage ratio. Off-Load Tap Changer (De-Energized Tap Changer - DETC): Adjustment can only be made when the transformer is de-energized. On-Load Tap Changer (OLTC): Can adjust taps while the transformer is energized and supplying load. This is a complex component, often housed in a separate compartment from the main tank to prevent contamination of the main oil. 2. The Tank and Cooling SystemMain Tank: A robust, welded steel tank that serves as the primary container for the active part and the insulating oil. It is designed to be airtight. Transformer Oil: A highly refined mineral oil or synthetic ester oil that fills the tank. Functions: Insulation: It is a superior dielectric medium, insulating the live windings from each other and from the grounded tank. Cooling: It circulates by natural convection (or is pumped), absorbing heat from the core and windings and dissipating it through the tank walls and radiators. Radiators and Tubes: Finned panels or banks of tubes attached to the main tank to increase the surface area for heat dissipation. The oil circulates through these, and heat is transferred to the surrounding air. Cooling Fans: For larger transformers, fans are mounted on the radiators to force air over them, significantly enhancing the cooling rate. This is known as forced-air cooling. Oil Pumps: In large transformers, pumps are used to force the circulation of oil, improving the heat transfer efficiency. 3. Protection and Monitoring AccessoriesThese are crucial for the safe and reliable operation of the transformer. Conservator (Expansion Tank): A smaller, cylindrical tank mounted above the main tank and connected to it via a pipe. It is only partially filled with oil. Function: It allows the main tank to be completely filled with oil. As the oil heats up and expands, or cools down and contracts, the oil level in the conservator rises and falls, preventing pressure build-up or a vacuum from forming in the main tank. Breather: A small container attached to the conservator, filled with a moisture-absorbing material like silica gel. As the transformer "breathes" due to temperature cycles, air passing through the breather is dried, preventing moisture from entering the oil and degrading its insulating properties. The silica gel is blue when dry and turns pink when saturated with moisture. Buchholz Relay: A very important gas-actuated relay installed in the pipe between the main tank and the conservator. Function: It detects internal faults. Minor faults generate slow gas bubbles which accumulate in the relay, triggering an alarm. Severe faults cause a sudden surge of oil, which trips the transformer's circuit breakers to disconnect it from the supply. It is a primary protection device. Sudden Pressure Relay: A modern alternative or supplement to the Buchholz relay that detects rapid pressure waves inside the tank caused by a major internal fault. Bushings: High-voltage, porcelain, or composite insulators that allow the electrical connections from the HV and LV windings to pass through the tank wall and connect 

China has achieved a breakthrough in developing a low-noise UHV reactor for transformers. The product passed type testing, witnessed by experts from the my country Electric Power Research Institute, with a measured noise level of just 61.6dB(A). Partial discharge was also kept below 10pC, with a minimum peak-to-peak amplitude of 5 microns. These figures mark a new global record for low-noise technology in large-capacity UHV reactors. The reactor features a dual-body design with direct-connected leads and oil-immersed, self-cooling technology. This product utilizes core technologies, including research and development results in vibration and noise reduction. By systematically suppressing vibration sources, isolating noise propagation, and damping vibration and acoustic waves, it effectively addresses long-standing engineering challenges associated with reactors, including high amplitude, high noise, and localized overheating. This breakthrough is significant because, as core equipment in high-voltage transmission systems, reactors have long faced challenges worldwide in terms of vibration, noise, and overheating due to their unique structure. These challenges are particularly significant in meeting my country's environmental protection requirements. This breakthrough has eliminated the need for external soundproofing enclosures for UHV equipment during actual operation, resolving noise pollution issues while also saving equipment costs and installation space. This technological breakthrough in transformers stems from an innovative spirit that dares to challenge established standards. During the R&D phase for enhanced power sand filling experiments, experts generally believed that finer sand was better, but our technicians persisted in experimenting with sand of varying particle sizes. After extensive testing, they discovered that sand with appropriate gaps in the sand actually achieved greater noise reduction. This approach, based on experimental data rather than blindly adhering to conventional wisdom, laid the foundation for the current technological breakthrough. The low-noise UHV reactor that passed this test will be used in my country's UHV power grid construction. Similar low-noise reactors, which entered operation in early 2025, are already in use in the western Sichuan UHV ring network, providing critical support for the "West-to-East Power Transmission" strategy. Compared to earlier products, the new reactor not only further reduces noise levels, but its systematic and innovative solution also provides key technical support for my country's efforts to build a green power grid and a new power system. This technological breakthrough not only solves engineering problems such as vibration, noise and local overheating that have long plagued the industry, but also provides key support for my country to build a green power grid and new power system.

Transformers are not indestructible. Rust in the core and windings—their lifeblood—can lead to increased iron losses, poor heat dissipation from the windings, decreased efficiency, and a hidden increase in power consumption. In severe cases, it can cause localized overheating, posing a safety hazard. Rust in fasteners and structural components can cause bolts to seize and reduce the strength of the enclosure, complicating routine maintenance and troubleshooting, significantly increasing operational costs and time. Corrosion is a slow, irreversible chemical reaction, accelerated dramatically by challenges such as salt spray in coastal areas, polluted gases in industrial areas, and high humidity during transportation and storage. For transformers, rust prevention is no small matter; it is crucial for ensuring power grid safety and improving economic efficiency. The Evolution and Breakthroughs of Rust Prevention TechnologyHumanity's battle against rust is a long one, and methods are constantly evolving. Traditional methods, such as applying rust-preventive oil or butter, are cumbersome, easily contaminated by dust, and require thorough cleaning before use, otherwise the transformer oil quality will be affected. Their protection period is short, making them inadequate for long-term storage and harsh transportation environments. The advent of VCI (vapor corrosion inhibitor) technology is revolutionary. This technology eliminates the need for direct metal contact. In a confined space, the anti-rust ingredients continuously evaporate and adsorb onto the metal surface, forming a protective film just a few molecules thick that effectively blocks moisture and corrosive substances. Even within complex internal structures, crevices, and holes, this technology provides comprehensive, no-blinds protection, lasting for years. Core Requirements of Modern Anti-Rust MaterialsAn excellent modern anti-rust packaging material should be a systematic solution, demonstrating the following capabilities: High Efficiency and Long-Lasting: Provides continuous protection for years, adapting to harsh environments such as temperature and humidity fluctuations.Full Coverage: Protects every geometric surface of the product, including hard-to-reach crevices and delicate areas.Clean and Environmentally Friendly: The material itself leaves no residue or contamination, allowing it to be used directly after removing the packaging.Convenient and Intelligent: Simple operation, eliminating the need for complex painting and cleaning processes.Customizable: Provides personalized solutions based on the size, shape, and specific needs of the equipment. Choosing an advanced rust prevention solution isn't just a cost expense; it's a crucial investment. It's an investment in the stability of the equipment's value, absolute operational reliability, reduced maintenance costs, and ultimately, the long-term security of the entire power grid system. With continuous advancements in materials science and technology, rust prevention technology is evolving towards a more environmentally friendly, intelligent, and integrated approach. In the future, we may see "smart rust prevention films" integrated with the Internet of Things (IoT) that monitor temperature, humidity, and corrosion factors inside packaging in real time, enabling predictive maintenance.

Industry standards and practical experiences suggest that well-maintained dry type transformers can serve effectively for up to 35 years or more under optimal conditions. In exceptional cases, they may even last up to 30 years. The service life of a dry-type transformer is primarily affected by the following factors: Temperature: Temperature is a significant factor affecting the service life of a dry-type transformer. High temperatures can cause insulation materials to age, weakening their insulation capacity and accelerating the decline in transformer life. Therefore, maintaining the normal operating temperature of the dry-type transformer is key to extending its service life. Load: The load of a dry-type transformer also affects its service life. Long-term overload operation can cause the transformer to overheat, damage the insulation materials, and shorten its service life. Therefore, it is crucial to properly manage the load when using a dry-type transformer. Ambient humidity: Humidity also has a significant impact on the service life of a dry-type transformer. High humidity can cause moisture in the insulation materials, leading to leakage and even short-circuit accidents. Therefore, it is important to carefully control the ambient humidity when installing a dry-type transformer. Maintenance: Regular maintenance can extend the service life of a dry-type transformer. For example, regular inspections of insulation material degradation and timely replacement of damaged parts are essential to ensure the longevity of a dry-type transformer. In general, the service life of a dry-type transformer is approximately 25 to 30 years, but the specific lifespan depends on a combination of the above factors. If dry-type transformers are properly operated and maintained, it is possible to further extend their service life.

As an indispensable key component of modern power systems, dry-type transformers are rapidly replacing traditional oil-immersed transformers worldwide with their unique oil-free design and superior safety performance. Basic Concepts and Operating Principles of Dry-Type Transformers Dry-type transformers are power transformers that do not use a liquid insulating medium (such as transformer oil). Instead, their windings and core are either directly exposed to the air or encapsulated with solid insulating material. Compared to traditional oil-immersed transformers, dry-type transformers use solid insulating materials (such as epoxy resin and fiberglass) to achieve electrical isolation between windings, completely eliminating the risk of oil leakage and fire. They are particularly suitable for applications requiring high safety and environmental protection. Based on the insulation method, dry-type transformers are mainly divided into two categories: impregnated (VPI) and cast (CRT). The former uses a vacuum pressure impregnation process to impregnate the windings with insulating varnish, while the latter uses vacuum-cast epoxy resin to form a solid insulating protective layer. In terms of their operating principle, dry-type transformers still adhere to the basic physical principle of electromagnetic induction. When alternating current passes through the primary winding, it generates alternating magnetic flux in the core, which in turn induces an electromotive force in the secondary winding, achieving voltage conversion. However, dry-type transformers implement this basic principle through unique structural design and material selection to optimize performance. For example, TBEA's newly developed patented dry-type transformer technology utilizes three parallel core legs with their axes perpendicular to the bottom surface. This effectively optimizes magnetic field distribution and reduces circulating and eddy current losses. This innovative core structure, combined with low-voltage windings and specially wound foil (with a winding angle controlled between 175° and 185°), significantly improves transformer energy efficiency. Dry-type transformers have a wide range of rated capacities, ranging from tens of kVA to tens of thousands of kVA, with 1000 kVA dry-type transformers being a mainstream product in the market. These transformers typically utilize laminated high-permeability silicon steel sheets for the core. The windings are vacuum-cast, and efficient heat dissipation is achieved through natural or forced air cooling systems. In terms of voltage level, dry-type transformers have developed from the traditional 10kV and 35kV to today's 66kV and even higher. The names of dry-type transformers generally reflect their technical characteristics. In the "SCB" series, "S" stands for three-phase, "C" for cast-type, and "B" for foil windings. The following number represents the performance level; for example, "SCB18" indicates energy efficiency that meets the Type 18 standard. With technological advances, the energy efficiency rating of dry-type transformers continues to improve. The use of new materials such as amorphous alloys has reduced both no-load and loaded losses by approximately 15%-20% compared to traditional oil-immersed transformers. These technological advances have made dry-type transformers increasingly critical in power system upgrades and the development of renewable energy. Core Structure and Material Innovations in Dry-Type Transformers The structural design of dry-type transformers directly determines their performance and service life. Modern dry-type transformers achieve safe, efficient, and reliable operation through sophisticated component configuration and innovative material application. A typical dry-type transformer consists of four core components: the core, windings, insulation system, and cooling system. Each component is meticulously designed and optimized to meet the demanding requirements of different application scenarios. The iron core structure forms the foundation of a dry-type transformer's magnetic circuit. It is typically constructed by laminating high-permeability cold-rolled silicon steel sheets. The thickness and lamination process of the silicon steel sheets directly impact the transformer's no-load losses. TBEA's latest patented technology demonstrates an innovative approach to iron core design: a structure with three parallel core legs, with their axes perpendicular to the base, effectively optimizes magnetic field distribution and reduces energy loss. Even more advanced are iron cores made from amorphous alloys, which can reduce no-load losses by over 30% compared to traditional silicon steel sheets, making them particularly suitable for applications with large load fluctuations. While costly, amorphous alloys offer significant energy-saving benefits over their entire lifecycle and are becoming a standard feature of high-end dry-type transformers. The winding system, as the circuit component of a dry-type transformer, has a direct impact on its load losses and short-circuit resistance. Modern dry-type transformer windings are primarily copper and aluminum. Copper offers superior conductivity but a higher cost, while aluminum offers a more competitive price. In TBEA's patented design, each core leg is equipped with a low-voltage winding, which is wrapped in multiple layers of foil around the outer circumference of the core leg. This structure not only improves efficiency but also reduces energy loss caused by eddy currents. The winding insulation is cast or impregnated with epoxy resin, creating a strong insulating protective layer that can withstand high voltage surges and effectively dissipate heat. The insulation system is a key feature that distinguishes dry-type transformers from oil-immersed transformers and is a crucial factor in their safety. Modern dry-type transformers primarily use epoxy resin casting or vacuum pressure impregnation (VPI) insulation methods. Epoxy resin casting completely seals the windings in the insulating material, providing excellent moisture and dust resistance. For example, Shunte Electric uses this technology to keep transformer noise in data centers below 50 decibels. VPI technology, on the other hand, uses multiple vacuum pressure impregnations to deeply infuse the insulating varnish into the windings, forming a uniform insulation layer. Jingquanhua's latest dry-type transformers feature an optimized insulation system design, providing a safer and more reliable power supply solution for data centers. The cooling system has a decisive influence on the load capacity and life of dry-type transformers. Since there is no oil as a cooling medium, dry-type transformers mainly rely on air convection to dissipate heat. Common cooling methods include natural air cooling (AN) and forced air cooling (AF). Large-capacity dry-type transformers are usually designed in AN/AF hybrid mode, which cools naturally under normal load and starts fans for forced cooling when overloaded. By optimizing the air duct design and heat dissipation area, 1000kVA dry-type transformers can keep the temperature rise within a reasonable range even under high load. Envision Energy's 66kV dry-type transformers for offshore wind turbines adopt an ultra-compact design, achieving efficient heat dissipation in a limited space, meeting the operating requirements in harsh offshore environments.

Electrical Knowledge | Key Differences Between Substations, Switchyards, Transformer Substations, Distribution Rooms, and Box Transformers Substation A substation is where voltage levels are transformed—either stepped up or down—to ensure stable transmission and distribution of electrical power. Substations handle voltages typically below 110 kV and often include voltage regulation, current control, and protection systems. Switchgear Station A switchgear station (also known as a switch station) is equipped with high-voltage equipment used exclusively for switching and distributing electricity. It does not include a main transformer, which distinguishes it from transformer substations. Transformer Substation This type of station includes one or more power transformers and is responsible for stepping voltage levels up or down. It plays a key role in voltage conversion and load distribution between the transmission and distribution networks. Distribution Room Also called a distribution station, this facility is focused on distributing electricity at lower voltages for end-user consumption. It contains mainly low- and medium-voltage switchgear and protects equipment downstream. Box-Type Transformer (Box Substation) A box-type transformer integrates a transformer, high-voltage switchgear, low-voltage distribution panel, metering, and compensation units into one compact enclosure. It's essentially a mini-substation used for fast deployment in urban or rural power networks. Each of these installations plays a unique role in the power supply chain, from large-scale voltage transformation to localized power delivery.

When a power transformer fails, the situation can be very serious, with consequences ranging from damage to the equipment itself to the paralysis of the entire power grid, and even safety incidents such as fire or explosion. Exactly what happens depends on the type of fault, its severity, the design of the transformer, and how quickly the protective devices can operate. Here are some possible scenarios: Abnormal phenomena (observable signs): Overheating: A large amount of heat is generated locally at the fault point, causing the oil temperature or winding temperature to rise sharply. The thermometer or thermal imager will alarm. Abnormal sound: Strong "buzzing", "crackling", "bursting" or even "roaring" sounds are heard inside. This is caused by strong electromagnetic vibrations caused by arc discharge, insulation material rupture, loose core or severe overcurrent. Abnormal oil level change: Gas generated by internal faults or large amounts of gas generated by high-temperature decomposition of insulating oil by arcs may cause abnormal oil level increase (increased pressure) or decrease (leakage). Oil spray or oil leakage: A sharp increase in internal pressure may cause the pressure relief valve to spray oil, or oil tanks, pipes, radiators and other parts may rupture and leak oil due to overheating, pressure or mechanical stress. Smoke and fire: High temperature and arcs may ignite insulating oil or solid insulating materials, causing the transformer to smoke or even catch fire. Gas generation: Insulating oil decomposes under high temperature and arcing to produce gases such as hydrogen, methane, ethane, ethylene, acetylene, carbon monoxide, carbon dioxide, etc. (Dissolved gas analysis/DGA is an important fault diagnosis method). Large amounts of gas accumulation may cause a sudden increase in pressure. Shell deformation or rupture: In extreme cases, huge internal pressure or arc energy may cause the transformer tank to swell, deform or even burst. Internal damage: Winding failure: Turn-to-turn short circuit: The insulation between adjacent turns in the same winding is damaged, forming a short-circuit loop and causing local overheating. Interlayer short circuit: The insulation between winding layers is damaged. Phase-to-phase short circuit: The insulation between different phase windings is broken. Winding short circuit to ground: The insulation between the winding and the core or tank (ground) is broken. Winding open circuit: The wire is broken or the connection point is unsoldered. Winding deformation/displacement: The huge short-circuit electromotive force causes the winding to mechanically deform, loosen or even collapse. Core failure: Core multi-point grounding: The core should be designed to have only one reliable grounding point. If there is an additional grounding point, a circulating current will be formed, causing local overheating or even melting of the core. Short circuit between core pieces: Damage to the insulating paint leads to short circuit between pieces, resulting in increased eddy current loss and overheating. Insulation system failure: Aging, moisture, and breakdown of solid insulation (cardboard, stays, etc.). Aging, moisture, contamination, carbonization, and decreased breakdown strength of insulating oil. Tap switch failure: Poor contact, contact erosion, insulation breakdown, mechanical jamming, or drive mechanism failure. Bushing failure: Flashover, dirty discharge, internal moisture or cracking leading to breakdown, or seal failure and oil leakage. Cooling system failure: Radiator blockage, fan/oil pump stoppage, cooling pipeline leakage, resulting in poor heat dissipation, temperature increase, accelerated insulation aging or failure. Impact on electrical system: Relay protection action: Transformers are equipped with multiple protections (differential protection, gas protection, overcurrent protection, pressure release protection, temperature protection, etc.). When a fault occurs, the relevant protection devices will quickly detect the abnormality (current imbalance, gas generation, pressure increase, excessive temperature) and act: Trip: Disconnect the circuit breaker connected to the transformer and isolate the faulty transformer from the power grid. This is the most critical link, aimed at preventing the accident from expanding. Alarm: Send out sound and light signals or remote alarm information. Voltage fluctuation or drop: The fault itself or the protection tripping will cause the bus voltage connected to the transformer to drop or fluctuate instantly, affecting the power supply quality of downstream users. Power supply interruption: If the faulty transformer is a key node in the power supply chain, its tripping will cause a large-scale power outage in the area it supplies power. System stability issues: The tripping of a large main transformer fault may disrupt the power balance and stability of the power grid, and in severe cases may cause a larger-scale power outage or even system collapse (cascading failure). Short-circuit current shock: A short-circuit fault inside the transformer will generate a huge short-circuit current, which will not only cause devastating damage to the transformer itself, but also cause huge electromotive force and thermal stress shock to the busbars, switchgear, lines, etc. connected to it. Safety risks: Fire and explosion: The sprayed high-temperature flammable insulating oil is very likely to cause a fire when it encounters air or electric arc. In a confined space, the oil-gas mixture may explode. This is the most dangerous situation. Toxic substance release: Burning insulating oil and insulating materials will release toxic smoke and gas. Equipment damage splash: Explosion or oil tank rupture may cause high-temperature oil, debris, and parts to splash, causing harm to personnel and nearby equipment. Environmental pollution: Large amounts of insulating oil leakage will pollute soil and water sources.

Understanding Transformer Structure: Key Components and Design Explained Body:Transformers play a vital role in power distribution, and their internal structure determines their performance and reliability. A standard transformer consists of the following main components: Core: Made of laminated silicon steel sheets to reduce energy loss and provide a magnetic path. Windings (primary and secondary): Copper or aluminum coils that transfer energy through electromagnetic induction. Insulation: Prevents electrical faults and ensures safe operation. Oil Tank: Usually contains oil (oil-immersed transformers) to dissipate heat and protect internal parts. Oil Conservator and Vent (Oil-immersed Transformers): Maintains oil level and prevents moisture intrusion. Cooling System: Air or oil-based system used to control heat. Bushing: Insulated terminals for external electrical connections. Understanding these components helps engineers and maintenance teams ensure optimal operation and life of the transformer.

1. Voltage level: Determined according to the input and output voltage requirements of the actual application scenario, it needs to match the grid voltage and the rated voltage of the electrical equipment, including the voltage values of the primary and secondary sides, such as the common 10kV/400V, etc.2. Capacity: Select according to the power demand of the load, considering the active power and reactive power of the load, generally in kilovolt-amperes (kVA), and need to meet the maximum power demand of the load, and appropriately reserve a certain margin to cope with possible load growth.3. Winding form: Commonly used are single-phase and three-phase windings. Single-phase is suitable for occasions with low power and single-phase loads, and three-phase is used for three-phase power supply and high power loads. In addition, there are special multi-winding transformers that can meet systems with multiple voltage output requirements.4. Core material: Mainly silicon steel sheet and amorphous alloy materials. Silicon steel sheet core is widely used and has good magnetic conductivity and cost performance; amorphous alloy core has lower iron loss, can effectively reduce energy consumption, and is suitable for occasions with high energy saving requirements.5. Cooling method: including oil-immersed self-cooling, oil-immersed air cooling, dry self-cooling, dry air cooling, etc. The oil-immersed type has good heat dissipation effect and large capacity, but the maintenance is relatively complicated; the dry type is more environmentally friendly, safe, and simple to maintain. It is often used in places with high requirements for fire prevention and explosion prevention.6. Short-circuit impedance: Short-circuit impedance affects the short-circuit current and voltage fluctuation of the transformer. Generally speaking, the short-circuit impedance is large and the short-circuit current is small, but the voltage change rate may be large. It is necessary to select a suitable short-circuit impedance value according to the stability of the system and the short-circuit capacity requirements.7. Insulation level: Determined according to the use environment and voltage level, it must be able to withstand the influence of factors such as overvoltage and insulation aging in the system to ensure the safe operation of the transformer, including the selection of insulation materials and the design of insulation structure.8. Overload capacity: Consider the possible short-term overload of the load, and select a transformer with appropriate overload capacity to ensure that it will not be quickly damaged when overloaded. Transformers of different types and designs have different overload capacities.9. Volume and weight: Due to the limitations of installation space and transportation conditions, in places with limited space, such as box-type substations, small distribution rooms, etc., it is necessary to choose transformers with small size and light weight, such as dry-type transformers or some specially designed compact transformers.10. Price and maintenance cost: Considering the purchase cost and the long-term maintenance cost, the prices of transformers of different brands, specifications and technical parameters vary greatly. At the same time, the maintenance costs of oil-immersed transformers and dry-type transformers are also different, and a comprehensive economic evaluation is required.

Basic knowledge of electricity: Analysis of four common transformer types and their application scenarios Transformers are indispensable core equipment in modern power systems, used to regulate voltage, transmit energy, and ensure stable power supply. According to different functions and applications, transformers are mainly divided into the following four types: Power transformers: used in high-voltage transmission systems to connect power stations and transmission lines. Distribution transformers: installed in residential or industrial areas, responsible for reducing high voltage to usable low voltage. Autotransformer: has a structure with some coils shared, small size, high efficiency, suitable for limited space occasions. Instrument transformers: including current transformers and voltage transformers, used for measurement and protection systems. Mastering these basic knowledge will help to more reasonably select and apply transformers and improve the efficiency and safety of power systems.

Any electrical equipment will suffer losses during long-term operation, and power transformers are no exception. The losses of power transformers are mainly divided into copper loss and iron loss. Definition and Principle Copper plays an important role in transformers. Copper wires are usually used in transformer windings. The "copper loss" in the transformer is the loss caused by the copper wires. The "copper loss" of the transformer is also called load loss. The so-called load loss is a variable loss, which is variable. When the transformer is running under load, there will be resistance when the current passes through the wire, resulting in resistance loss. According to Joule's law, this resistance will generate Joule heat when the current flows through it, and the greater the current, the greater the power loss. Therefore, the resistance loss is proportional to the square of the current and has nothing to do with the voltage. It is precisely because it changes with the current that the copper loss (load loss) is a variable loss, and it is also the main loss in the operation of the transformer. Influencing factors Current size: As mentioned above, copper loss is proportional to the square of the current, so the current size is the key factor affecting copper loss.Winding resistance: The resistance of the winding directly affects the copper loss. The larger the resistance, the higher the copper loss. Number of coil layers: The more coil layers there are, the longer the path for the current to flow in the winding, and the resistance will increase accordingly, resulting in increased copper loss. Switching frequency: The effect of switching frequency on transformer copper loss is directly related to the distributed parameters and load characteristics of the transformer. When the load characteristics and distributed parameters are inductive, the copper loss decreases with the increase of switching frequency; when they are capacitive, the copper loss increases with the increase of switching frequency. Temperature influence: Load loss is also affected by the temperature of the transformer. At the same time, the leakage flux caused by the load current will generate eddy current loss in the winding and stray loss in the metal part outside the winding. Calculation method There are two calculation formulas1. Formula based on rated current and resistance:Copper loss (unit: kW) = I² × Rc × ΔtWhere I is the rated current of the transformer, Rc is the resistance of the copper conductor, and Δt is the operating time of the transformer.2. Formula based on rated current and total copper resistance: Copper loss = I² × RWhere I represents the rated current of the transformer, and R represents the total copper resistance of the transformer. The total copper resistance R of the transformer can be calculated by the following formula: R = (R1 + R2) / 2Where R1 represents the primary copper resistance of the transformer, and R2 represents the secondary copper resistance of the transformer. Methods to reduce copper loss Increase the winding cross-sectional area of the transformer: reduce the conductor resistance, thereby effectively reducing the copper loss of the transformer. Use high-quality conductor materials: such as copper foil or aluminum foil to reduce winding resistance. Reduce the light-load operation time of the transformer: limit the proportion of the time when the transformer is light-loaded, which is conducive to reducing the copper loss of the transformer.

Siemens Energy expects to start making large industrial power transformers in the U.S. in 2027 and could further expand its Charlotte plant if demand and import tariffs remain high, senior executives said. Siemens Energy, which gets more than a fifth of its sales in the U.S. and has about 12% of its roughly 100,000 employees in the U.S., has several plants making wind and gas turbines as well as grid components. Overall, more than 80% of so-called large power transformers (LPTs) -- bus-sized components needed to convert grid transmission voltage levels -- are currently imported into the U.S., said Tim Holt, a Siemens Energy board member. That’s why Siemens Energy is expanding its plant in Charlotte, North Carolina, with the first local LPTs expected to roll off the factory line in early 2027, Holt said, adding that there is plenty of room for further expansion if needed. The company expects total investment in the outdated U.S. grid to reach $2 trillion by 2050, as power demand is expected to surge thanks to data centers needed for artificial intelligence technology. “This time, we expect the boom cycle for grid expansion to be longer than the usual two to three years. The market is very optimistic now,” Holt, who runs Siemens Energy’s U.S. business, said at a company event. Maria Ferraro, finance chief at Siemens Energy, said the group was taking a medium- to long-term view on the U.S. market, where some companies are rethinking their footprint in the wake of U.S. President Donald Trump’s trade war. “Will we change our strategy or the way we approach the U.S.? I would say no, because we already have a long-term foundation there and it’s a key market for us,” Ferraro said. Siemens Energy said in May it expected U.S. import tariffs to reduce group net profit by less than 100 million euros ($117 million) in 2025 after Trump threatened to impose 50% tariffs on EU goods if no deal was reached by July 9. “Any significant change in tariffs would also mean we review our estimated impact,” Ferraro said.

April 28-29, 2025 Wuxi, Jiangsu The "2025 China Power Transformer Overseas and Intelligent Manufacturing Technology Conference" hosted by Shanghai Mogen Enterprise Management Consulting Co., Ltd. was successfully held at Wuxi Xizhou Garden Hotel from April 28 to 29, 2025. This conference brings together top industry scholars, industry leaders, investment institutions and policy makers. It will conduct in-depth discussions on core areas such as transformer overseas expansion and intelligent manufacturing, injecting new impetus into the coordinated development of the power transformer industry. The technological progress and innovation of China's transformer industry cannot be separated from the continuous and in-depth exchanges and cooperation between enterprises and industry elites. As an important industry exchange event, the 2025 China Power Transformer Overseas and Intelligent Manufacturing Technology Conference not only played an important role in promoting industrial technology cooperation and exchanges, and transformer enterprises going overseas, but also effectively accelerated the supply and demand docking and cooperation process in the upstream and downstream of the transformer industry chain.