Distribution Transformers

SBH Series Amorphous-Core Oil-Immersed Transformer

Product Overview

SBH15/21/25-M Series

Product Overview
The SBH amorphous alloy transformer utilizes advanced amorphous alloy strips to construct its wound core, leveraging the material’s isotropic soft magnetic properties to achieve significantly reduced no-load losses. For enhanced operational resilience, the low-voltage side employs precision-wound copper foil coils that substantially improve short-circuit withstand capability. The unit offers flexible connection groups (Dyn11 or Yyn0) to mitigate harmonic distortion within power networks, thereby optimizing power quality across diverse grid conditions.
During manufacturing, the vacuum degassing process thoroughly eliminates residual air bubbles within insulation systems, ensuring long-term dielectric stability under demanding operating environments. This engineering approach synergistically combines ultra-low electromagnetic losses with exceptional energy efficiency, delivering reliable performance for critical applications including renewable energy integration and urban grid modernization projects.

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Model Definition

Features

● Voltage level: 10~35/0.4kV

● Capacity: 30~2500kVA

● Core Material: Utilizes an amorphous alloy core with an optimized molecular structure to ensure precise three-phase magnetic balance, effectively preventing the generation of third harmonics through its uniform magnetic properties.

● Harmonic Filtering: Incorporates a specially designed low-voltage coil structure with an interleaved winding arrangement, which works to dynamically reduce higher-order harmonics by balancing magnetic field distributions.

● Energy Efficiency: Takes advantage of the core material’s superior magnetic characteristics to significantly cut down on no-load losses and minimize excitation current, achieving notable energy-saving performance that meets high-efficiency standards.

● Sealing Technology: Adopts a fully sealed tank design combined with a vacuum oil injection process, which creates a protective barrier against oxidation and leakage. This design requires no maintenance and is built to ensure a long operational lifespan.

● Thermal Performance: Features a low-heat-generating design paired with an efficient heat dissipation system, allowing the equipment to handle overload conditions effectively while maintaining stable thermal performance.

Range of application

Power distribution for power grid construction, power distribution engineering renovation projects, high-rise buildings, densely populated residential areas, important government agencies, airports, subways, stations, industrial and mining enterprises, petrochemicals, power plants, ports and docks, and other places with requirements for fire and explosion prevention.

Technical specifications

Rated capacity (kVA)	Rated voltage			Vector group	No-load loss (W)			Load loss (W)			No-load current (%)	Impedance voltage (%)
Rated capacity (kVA)	HV (kV)	Tapping range (%)	LV (kV)	Vector group	15#	21#	25#	15#	21#	25#	No-load current (%)	Impedance voltage (%)
100	6 6.3 6 10 10.5 11	±5 Or ±2×2.5	0.4	Dyn11 Or Yyn0	75	75	60	1580	1350	1270	0.1	4
125					85	85	70	1890	1615	1530	0.1	4
160					100	100	80	2310	1975	1870	0.1	4
200					120	120	95	2730	2330	2210	0.1	4
250					140	140	110	3200	2735	2590	0.2	4
315					170	170	135	3830	3275	3100	0.2	4
400					200	200	160	4520	3865	3660	0.3	4
500					240	240	190	5410	4625	4380	0.3	4
630					320	320	250	6200	5300	5020	0.3	4.5
800					380	380	300	7500	6415	6075	0.3	4.5
1000					450	450	360	10300	8800	8340	0.4	4.5
1250					530	530	425	12000	10260	9720	0.4	4.5
1600					630	630	500	14500	12400	11745	0.3	4.5
2000					720	710	550	18300	14800	14000	0.3	5
2500					865	860	670	21200	16300	15450	0.25	5

Note: The above data is subject to change due to technical improvement.

Additional Product Overview

SBH15/21/25-M Series

Product Overview

The SBH Series Fully Sealed, Maintenance-Free Oil-Immersed Power Transformers are high-efficiency, reliable power distribution equipment engineered for modern power systems. Featuring a fully sealed structural design, the product achieves complete isolation between the tank and external environment through precision welding processes. This effectively blocks intrusion of moisture, dust, and other impurities, fundamentally preventing issues such as insulating oil aging and core corrosion, thereby significantly extending equipment service life to over 20 years.

Core components feature amorphous alloy cores and high-quality insulating materials, combined with vacuum oil-filling technology to ensure low loss and low noise during operation. No-load loss is reduced by 15%-20% compared to traditional silicon steel sheet transformers, meeting national Class I energy efficiency standards with outstanding energy-saving advantages.

The equipment accommodates voltage levels of 10kV-35kV with capacity coverage from 50kVA to 2500kVA. It is widely deployed in urban distribution networks, industrial parks, high-rise buildings, and other scenarios with stringent reliability and stability requirements, providing safe, efficient, and long-lasting core support for power transmission.

Model Definition

Features

² Voltage level: 10~35/0.4kV

² Capacity: 30~2500kVA

² Hermetically Sealed and Reliable with a Long Service Life: The fully hermetic structure completely isolates transformer oil from the external environment, preventing oil oxidation, insulation moisture absorption, and impurity intrusion—greatly extending the equipment’s service life. Meanwhile, it resists corrosion from harsh environments and reduces failure risks, serving as a core guarantee for the long-term stable operation of the equipment.

² Energy-Efficient and Cost-Effective in Operation: Adopting an oil-immersed self-cooled design, it requires no auxiliary energy consumption. Combined with an optimized core-type magnetic circuit and double-winding structure, both no-load loss and load loss are maintained at low levels. It delivers significant energy-saving effects during long-term operation, continuously reducing users’ electricity costs and meeting the demand for cost reduction and efficiency improvement.

² Stable Structure with Strong Anti-Interference and Durability: The three-phase core-type structure features a symmetrical magnetic circuit, ensuring stable power supply voltage and reducing harmonic interference. The double windings boast high mechanical strength, excellent short-circuit resistance, seismic resistance, and vibration resistance—capable of withstanding power grid impacts and the challenges of complex installation environments, thus minimizing the probability of downtime due to faults.

² Convenient Maintenance and Low Comprehensive Cost: The hermetic structure eliminates the need for oil refilling or replacement, requiring only simple daily inspections. The off-circuit tap-changing design is simple with a low failure rate, eliminating the need for frequent maintenance by professional personnel. This not only saves labor and time but also reduces maintenance procedures and environmental pressure.

² Wide Adaptability and Flexible Application Scenarios: The three-phase design is compatible with mainstream power systems, and the double-winding structure accurately matches voltage transformation between two levels. The combined characteristics of hermetic sealing and self-cooling make it suitable for various scenarios, including outdoor, indoor, high-humidity, and dusty environments. It can meet the power distribution needs of urban and rural power grids, industrial facilities, commercial buildings, residential areas, and other applications.

Range of application

The S-M Series Three-Phase Oil-Immersed Self-Cooled Hermetically Sealed Off-Circuit Tap-Changing Core-Type Double-Winding Distribution Transformer, leveraging its core advantages of reliable hermetic sealing, high energy efficiency, and wide adaptability, is widely applied in various three-phase power distribution network scenarios, covering fields such as urban and rural power grid construction, industrial production, commercial and public buildings, outdoor and special environments, as well as people’s livelihood and infrastructure supporting facilities.

Oil-Immersed Transformer Components

Reference component and partner-factory production images. Components, conservator and breather availability depend on the selected design.

Test Control Panel

Steel control panel operating routine-test circuits (ratio, insulation resistance, dielectric) for safe, standard-compliant testing.

Flange Connection

High-strength bolted flange with machined sealing face and oil-resistant gasket — a leak-free oil path for the long run, and easy to open when service is needed.

Finished Porcelain Bushings

Multi-shed porcelain bushings increase creepage distance to cope with outdoor dust and rain.

Transformer Core and Clamp Structure

Painted steel clamps and tie rods hold the laminations tight to cut noise, with single-point core earthing to prevent floating discharge.

Heat Dissipation Panel

Pressed or welded steel fins, phosphated and powder-coated, enlarge the radiating surface and release heat by natural oil convection.

Silica Gel Breather

The silica gel breather is installed at the end of the conservator breathing pipe. The color-indicating silica gel inside appears blue/purple when dry and turns pink once saturated, allowing a quick visual check for replacement. As the oil volume expands and contracts, the breather continuously filters the air entering the conservator and prevents moisture from reaching the transformer oil — a key component for maintaining insulation performance. The oil cup at the bottom allows oil-level observation and dust separation.

Oil-Immersed Transformer Production Line

Reference image from the partner factory. Standardized line covering assembly, drying, oil filling and painting ensures batch consistency and short lead times for export orders.

10 kV Distribution Transformer Testing Area

Reference image from the partner factory. Finished S11/S13/M units are tested one by one before dispatch, verifying electrical and insulation performance with test reports supplied.

Oil-Immersed Transformer Applications

Typical application scenarios. The installations shown are examples; voltage, capacity and mounting arrangement require project-specific confirmation.

Pole-Mounted Transformer: Rural Supply

Where used: Serves scattered rural loads such as village supply and irrigation wells — pole-mounted for minimal land use, fast installation and low cost.

Outdoor Substation: Regional Grid

Where used: Main-transformer bays of 35–110 kV substations, stepping down and distributing power to cities, towns and industrial load centers.

Solar Power Station: Grid Connection

Where used: Steps up PV inverter output to 10/35 kV for grid connection, coping with strong UV, wide temperature swings and day-full / night-light duty.

Industrial Park: Factory Supply

Where used: Supplies industrial parks, plants and mine processing facilities — production lines, large motors and compressors — with dust-resistant, continuous heavy-load capability.