Oil-immersed power transformer S13/S20/S22-M-30–2500/10
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The transformer is housed in a hermetically sealed tank, completely isolated from the external atmosphere. Changes in oil volume are compensated by the elastic deformation of the tank’s corrugated walls, thereby preventing direct contact between the insulating oil and the ambient air. This design minimizes moisture ingress and oxidation, extending the service life of the insulation.

The hermetic design eliminates the need for a core‑lifting inspection prior to commissioning and significantly reduces maintenance requirements during operation, thereby enhancing operational reliability.

The transformer is designed using PCCAD software and complies with IEC 60076 and GB 1094 standards. Production is carried out in accordance with an ISO 9001‑certified quality management system.

The coil is wound with high-strength enameled conductors (or paper‑insulated conductors) in a cylindrical or disc‑shaped configuration. The ampere‑turn distribution is uniform, and the insulation system is optimized to ensure high short‑circuit withstand capability.

All internal fasteners are secured with self-locking nuts to ensure long-term mechanical reliability under the influence of light, thermal, and electrical stresses. The transformer is equipped with a thermometer featuring telemetry functionality and a pressure relief valve, thereby guaranteeing safe and reliable operation.

• The hermetic design eliminates the need for an oil conservator, a moisture‑absorbing device, and other oil‑preservation equipment by isolating the insulating oil from atmospheric air and minimizing oxidation. Under normal operating conditions, the insulating oil is rated for a service life of up to 20 years without requiring major maintenance.
• High-performance rubber sealing components are employed, and vacuum oil-filling technology is utilized to ensure reliable sealing.

The transformer is widely used in urban power distribution networks, as well as in industries such as petrochemicals, metallurgy, textiles, and mining. It is particularly well suited for operation in high-humidity environments or at facilities with limited access for maintenance.

SBH15-M-30 ~ 2500/10 series distribution transformer with oil cooling and amorphous alloy core
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Oil‑filled transformers with amorphous‑alloy cores represent an energy‑efficient alternative to conventional transformers with silicon electrical steel cores and are widely used in outdoor power distribution systems. The widespread adoption of these products in distribution networks contributes to substantial energy savings and reduced carbon emissions.

The fully sealed design prevents contamination of the insulating oil and the insulation system, ensuring reliable operation in high-humidity conditions. The transformer is suitable for both urban and rural distribution networks, particularly in areas with limited power supply, significant load fluctuations, or restricted access for maintenance.

• The transformer is equipped with a three-phase amorphous core featuring three limbs, incorporating a patented second-generation amorphous‑alloy transformer technology. As a result, the transformer operates with reduced noise levels and enhanced operational reliability.
• The high-voltage winding is designed as a multi-layer cylindrical structure to optimize the distribution of impulse voltage.
• For transformers with ratings from 200 to 6,300 kVA, the low-voltage winding is designed in a cylindrical or helical configuration, ensuring high mechanical strength, uniform ampere-turn distribution, and excellent short-circuit withstand capability.
• The active part of the transformer is equipped with positioning devices that prevent displacement during transportation. All fastening elements are secured with lock nuts, which eliminate loosening over prolonged operation and enable maintenance without lifting the core.
• Before applying the primer and finish coat, the housing surface undergoes degreasing, rust removal, and phosphating, ensuring reliable corrosion resistance under conditions of high humidity and contamination. Its compact design minimizes installation space and guarantees maintenance-free operation.

Distribution transformers with natural ester insulation SW13/SW14-M-30–2500/10
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Insulating liquids based on natural esters are widely recognized as environmentally friendly and less flammable dielectric fluids. Relevant industry standards have been developed, including ASTM D6871, IEEE C57.147, ABNT NBR 15422, and applicable IEC specifications.

Liquids based on natural esters are recognized by the U.S. National Electrical Code (NEC) and have received approvals from FM Global and Underwriters Laboratories (UL). They are also acknowledged by the U.S. Environmental Protection Agency (EPA) for their environmental benefits.

• Although additional secondary containment tanks may be required, spills of natural esters can be cleaned up using conventional methods without classifying them as hazardous waste.
• The use of an insulating fluid based on natural esters helps reduce the risk of non‑compliance with environmental regulations and simplifies spill‑management procedures.

• The vegetable-oil-based insulating fluid has a flash point exceeding 350 °C, which significantly surpasses the minimum threshold of 300 °C stipulated by IEC, GB, and NEC standards, thereby substantially enhancing the safety of transformers and power systems.
• Tests conducted in accordance with the international standard ASTM D1354 have shown that vegetable oil exhibits superior performance compared to mineral oil in terms of ignition time, self-extinguishing time, and smoke generation rate.
• According to UL certification, vegetable‑oil‑based insulating fluid has a flammability rating of 4–5, which is significantly lower than the 10–20 rating for paraffin‑based mineral oil.
• Section 450-23 of the NEC additionally recognizes liquid‑filled transformers with a high flash point, permitting their use in areas where enhanced fire protection is required.

• An insulating fluid based on natural esters enhances the fire safety of transformers and reduces the risk of fire‑related incidents, thereby minimizing potential economic losses, such as equipment damage, repair and replacement costs, and liabilities associated with power supply interruptions.
• When using an insulating fluid based on natural esters, fire safety requirements can be optimized in confined spaces. In certain applications, and subject to approval by local regulatory authorities, the need for additional fire‑protection measures—such as sprinkler systems or firewalls—may be reduced. Consequently, transformers filled with natural esters are well suited for installation indoors or in space‑constrained environments.

• Compared with mineral oil, natural ester insulating fluid exhibits a significantly higher water saturation limit across all operating temperatures. Under normal service conditions, its moisture saturation level typically exceeds that of mineral oil by a factor of 5 to 8.
• In insulation systems based on natural esters, the equilibrium moisture content in cellulose insulation is lower than in systems using mineral oil. During hot‑oil drying, components impregnated with natural esters can reduce drying time, thereby enhancing production efficiency and the operational performance of the insulation.

• Compared with paper‑impregnated mineral‑oil systems, cellulose insulation impregnated with a natural ester exhibits a lower rate of thermal aging. As a result, the service life of the insulation system is extended, which helps prolong the transformer’s operational life and enhance its overload capability.
• Cellulose insulation impregnated with a natural ester enables transformers to operate under higher peak loads or overloads. Compared with systems based on mineral oil and paper, it can be operated at the hottest‑spot temperatures approximately 10–15 °C higher while maintaining an equivalent service life.

Smart distribution transformer with automatic on-load power and voltage regulation S13/S14-M·ZT
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The S13 model three-phase oil-immersed on-load voltage-regulating distribution transformer is a next-generation product featuring high energy efficiency. Its performance characteristics comply with the requirements of Energy Efficiency Class II as specified in China’s National Standard (GB).

The transformer adjusts its operating capacity in response to seasonal or cyclical load fluctuations by means of an on‑load tap changer. By optimizing the power rating, transformer losses are effectively reduced, resulting in substantial energy savings.

For many years, rural distribution networks have been characterized by load dispersion, pronounced seasonal variability, and low average load factors.

Conventional distribution transformers are typically selected based on the maximum load. Under light-load conditions, these transformers often operate for extended periods at no load or under low load, resulting in relatively high inherent losses.

Therefore, transformers selected for the construction and modernization of rural power grids must meet the specific load characteristics of rural networks. The transformer should be capable of adjusting its output capacity in response to actual loading conditions, thereby reducing both no-load losses (internal losses) and load losses.

At the same time, the installed distribution transformer must deliver high technical performance and reliable operation, meeting both current requirements and the needs of future development in the years ahead.

Our S13 voltage regulating transformer with load‑regulation capability is designed as an energy‑efficient solution based on adaptive load‑management principles. It automatically adjusts voltage and power in response to fluctuations in grid voltage and changes in load, ensuring stable power quality while reducing no‑load losses. Equipped with remote communication features, the transformer supports real-time monitoring and agile control via mobile apps and intelligent management systems.

• Automatic voltage regulation

When voltage fluctuations occur due to unstable consumer demand or changes in line load, the transformer automatically adjusts voltage levels to maintain stable output power.

This function improves power quality, extends the service life of electrical equipment, and enhances voltage compliance with regulatory standards during both peak and off-peak load periods in the distribution network.

• Automatic power regulation

The transformer automatically adjusts its power output in response to the load. During periods of low load, it switches to a reduced-power mode, significantly reducing no-load losses.

When operating at reduced power, no-load losses are approximately one-third lower than at full power, resulting in substantial energy savings.

• Monitoring of distribution and four remote control functions via wireless communication

The load and voltage regulating switch supports multiple wireless communication methods, including Wi‑Fi, GSM, and GPRS.

It provides real-time monitoring, remote control of the transformer’s operating status, parameter viewing and modification, and supports remote measurement, remote signaling, remote control, and remote regulation functions.

This enables the automation of zone management for distribution transformers within the power grid.