Step-Up Solar Inverter Transformers & Three-Phase Distribution Transformers — Overview

As one of the trusted manufacturers of oil-immersed power transformers, we specialize in designing, testing, and producing transformers that meet the highest standards of performance and reliability. With decades of engineering expertise, our team is committed to continuous innovation, strict quality control, and professional customer service.

Our product portfolio includes S11, S13, S18, S20, and S22 series oil-immersed power transformers, suitable for three-phase 50Hz and 60Hz power grid systems. They are widely used for primary input and secondary output in power networks, and are engineered for high efficiency, low loss, and long-term stable operation.

Ensuring dependable power is crucial for utility substations, industrial facilities, renewable energy projects, and commercial applications. We deliver tailored transformer solutions that comply with both international and national standards, including IEC60076, GB/T6451, GB1094, and GB20052-2024.

Product 01

Three-Phase Distribution Transformer (Oil-Immersed)

Operating on the principle of electromagnetic induction, this transformer efficiently converts alternating voltage and current to facilitate the transmission and distribution of electrical energy. It is constructed with a closed laminated iron core wound with two or more isolated windings of different turn counts. When the primary winding is energized by an AC power supply, an alternating magnetic flux is generated in the core. This flux induces an electromotive force in the secondary winding, enabling voltage transformation according to the turns ratio between windings while achieving efficient power transmission.

Features

Insulating Medium: Utilizes mineral oil or synthetic dielectric oil as the primary insulation and cooling medium. Sealed Structure: The windings and iron core are fully immersed in oil and hermetically sealed within a robust steel tank.
Heat Dissipation Design: The tank is equipped with cooling fins, tubes, or radiators on the exterior, facilitating heat dissipation through natural or forced oil circulation.
Protection Devices: Commonly includes a conservator (oil expansion tank), breather, Buchholz relay, and pressure relief valve to ensure operational monitoring and safety protection.
Material Cost: Primarily constructed using insulating pressboard and steel, resulting in relatively low material costs.

Data Sheet â€” click to enlarge

Advantages

Excellent Heat Dissipation and Strong Overload Capacity: The insulating oil offers high thermal conductivity, enabling effective handling of short-term overload conditions.
High Reliability and Long Service Life: The oil-immersed and sealed structure effectively prevents insulation aging, with a design lifespan exceeding 20 years.
Cost-Effectiveness and Low Operating Expenses: Manufacturing and acquisition costs are more competitive compared to dry-type transformers, especially in high-capacity applications.
Wide Capacity Range: Capable of supporting large capacities (up to tens of MVA) and high voltage levels (e.g., above 35 kV) with relative ease.
Mature Technology and Easy Maintenance: With a century of development, the technology system for maintenance, diagnostics, and repair is highly advanced and well-established.
Low Operating Noise: The oil and tank structure provide damping effects on electromagnetic vibrations, resulting in relatively quiet operation.

Product 02

Oil-Immersed Wind Power Transformer

The oil-immersed wind power transformer is specifically designed for harsh operating environments in wind farms. It is typically installed inside the wind turbine tower or on the base platform. Its primary function is to step up the low voltage generated by the wind turbine (e.g., 0.69 kV or 35 kV) to a higher grid transmission voltage (e.g., 35 kV or 110 kV), thereby reducing energy loss during power transmission.

Features

Environmental Adaptability: Excellent weather resistance, designed to withstand harsh conditions including high humidity, salt spray (for offshore wind power), windblown sand, and extreme temperature variations.
High Short-Circuit Withstand Capability: Utilizes high-strength electromagnetic wire and specialized winding techniques to endure frequent load fluctuations and grid disturbances in wind power systems.
Compact Design: Features a space-saving structure with a relatively small footprint to meet strict installation constraints within wind turbine towers or on platform bases.
Superior Sealing Performance: Hermetically sealed construction or equipped with pressure relief devices to prevent moisture and air ingress, delay insulation aging, and extend maintenance-free operation periods.
Outstanding Overload Capacity: Designed to accommodate short-term overloads during periods of high wind energy availability, maximizing energy utilization efficiency.
Low Loss Characteristics: Manufactured with high-quality silicon steel cores and advanced engineering to minimize no-load and load losses, complying with energy efficiency and environmental requirements.

Data Sheet â€” click to enlarge

Advantages

High Reliability: Specifically engineered for the unique demands of wind power applications, featuring a robust internal structure and extremely low failure rates to ensure long-term stable operation of wind farms.
Long Service Life: Excellent sealing and insulation systems effectively delay aging, with a design lifespan that matches that of wind turbines (typically 20â€“25 years).
Low Maintenance Requirements: The fully sealed design requires virtually no maintenance, greatly reducing the frequency of tower access and lowering lifecycle maintenance costs.
High Grid Integration Efficiency: Low-loss characteristics minimize energy waste during the voltage step-up process, enhancing the overall economic performance of wind power projects.
Safety and Environmental Friendliness: Advanced oil preservation systems (such as pressure relief devices and gas relays) ensure operational safety. Many products are also compatible with biodegradable ester fluids, further improving environmental sustainability.

Product 03

Step-Up Solar Inverter Transformer (Oil-Immersed PV)

The oil-immersed PV transformer is a critical transmission and distribution equipment in PV power stations. It is typically installed within pad-mounted substations (PV-compatible compact substations) or deployed as a standalone unit. Its primary function is to step up the medium voltage output from PV inverters (e.g., 0.8 kV or 35 kV) to the grid transmission voltage level (e.g., 35 kV or 110 kV), enabling efficient grid integration. Serving as a "key gateway," it plays an essential role in delivering clean solar energy to the power grid.

Features

High-Temperature Resistance: Designed for the significant daily temperature variations and high daytime heat in PV power stations, the transformer oil and insulation system deliver excellent high-temperature endurance.
Strong Overload Capacity: The design accommodates full-load and even short-term overload operation during peak sunlight hours, as well as extreme duty cycles like nighttime no-load conditions.
Harmonic Handling Capability: Utilize special design and materials to withstand specific harmonic currents generated by PV inverters, preventing local overheating.
High Sealing Performance: A fully sealed structure or devices equipped with pressure relief effectively prevents the intrusion of moisture, dust, and salt spray (suitable for coastal/desert power plants), making it ideal for harsh outdoor environments.
Energy Efficiency with Low Losses: Specially optimized for low no-load loss (during nighttime and periods without sunlight), along with reduced load loss, aligning with the core requirements of energy conservation and efficiency in PV power plants.
High Reliability: Robust construction and high-quality internal materials ensure long-term, stable operation in unmanned PV power stations.

Data Sheet â€” click to enlarge

Advantages

Cost-Effectiveness, Better Value: Compared to dry-type transformers, oil-immersed transformers offer lower manufacturing and procurement costs at equivalent capacity, making them an economical choice for large and medium-sized PV power stations.
Minimal Maintenance, Extended Lifespan: With a rugged sealed construction and stable oil-paper insulation system, these transformers are virtually maintenance-free and designed to last over 25 years â€” making them a durable match for the lifecycle of solar power stations.
High Efficiency, Higher IRR: Reduced no-load and load losses directly decrease the station's internal power consumption (auxiliary power rate), increasing both energy generation and overall investment return rate (IRR).
Strong Environmental Adaptability: Excellent heat dissipation and sealing performance enable wide application in diverse PV sites â€” such as deserts, hills, and water surfaces â€” with extreme conditions including high temperature, humidity, altitude, and wind-blown sand.
Safe and Dependable Operation: Comprehensive protection devices (e.g., pressure relief valve, gas relay) and low failure rates ensure safe and stable grid-connected power generation.

Product 04

Oil-Immersed ESS Transformer

The Oil-Immersed ESS Transformer is a critical hub device in Battery Energy Storage Systems (BESS), primarily enabling bidirectional energy transfer and voltage conversion. During charging, it steps down the grid's high voltage to a level suitable for the Power Conversion System (PCS) input. During discharging, it steps up the PCS output voltage to match the grid voltage. Serving as the core link between the battery units and the grid, it plays a vital role in ensuring the efficiency, safety, and stability of the energy storage system.

Features

Bidirectional Operation Design: Specifically engineered for frequent and rapid charge-discharge cycles, delivering high efficiency and reliability in both operating modes.
Exceptional Overload Capacity: Capable of withstanding short-term high-current impacts and frequent load fluctuations caused by peak shaving and frequency regulation in energy storage systems.
High Harmonic Tolerance: Designed with specialized materials and construction (e.g., reduced eddy current losses) to endure high levels of harmonic currents generated by PCS operation, preventing localized overheating and additional losses.
High Reliability Requirements: Designed to exceed standard distribution transformer requirements to ensure long-term, stable operation in unmanned energy storage stations and minimize downtime.
High Energy Efficiency: No-load and load losses are optimized â€” particularly in common operating ranges â€” since even minor losses directly affect the round-trip efficiency of the energy storage system.
Excellent Thermal Management: The oil-immersed design ensures superior heat dissipation, effectively managing internal temperatures under bidirectional and heavy-load conditions to preserve insulation integrity and service life.

Data Sheet â€” click to enlarge

Advantages

Improved System Efficiency, Increased ROI: The low-loss design minimizes energy waste during conversion, enhancing the charge-discharge efficiency of the energy storage system and directly increasing the economic returns of the power station.
Adaptability to Demanding Conditions, High Stability: With a robust structure and specialized engineering, it performs reliably under harsh operating modes such as frequent switching and drastic load changes, ensuring safety and stability on both grid and battery sides.
Lower Lifecycle Cost (TCO): Features a lower initial investment compared to dry-type transformers, combined with minimal maintenance requirements, resulting in significant total cost of ownership (TCO) advantages over its lifespan.
Long Service Life Design: Excellent insulation and thermal management systems ensure a service life aligned with energy storage power stations (typically 15â€“20 years), making it a durable and reliable long-term asset.
Wide Environmental Adaptability: The sealed oil-immersed construction allows reliable operation in diverse climatic conditions, including high temperature, high humidity, high altitude, and other extreme environments in energy storage projects.

Step-Up & Step-Down Power Transformers Manufacturer

Step-Up Solar Inverter Transformers & Three-Phase Distribution Transformers — Overview

Three-Phase Distribution Transformer (Oil-Immersed)

Oil-Immersed Wind Power Transformer

Step-Up Solar Inverter Transformer (Oil-Immersed PV)

Oil-Immersed ESS Transformer

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