Power Transformer

Daelim Transformer, a UL, cUL, and CSA certified power transformer manufacturer, adheres to global standards such as ANSI/IEEE/IEC/CSA/AS and NEMA. They offer transformers with ratings up to 270 MVA and insulation levels up to 800 kV. Daelim excels in providing innovative electrical transformer solutions, prioritizing safety and sustainability while meeting rigorous standards.

Each transformer is uniquely designed, considering factors like voltage, power rating, climate, and network topology. These solutions prioritize efficiency, eco-friendliness, high short-circuit strength, overload capacity, high-temperature operation, reliable startup during outages, and cost-effective maintenance. Their applications span renewable energy, urban substations, utilities, and industrial sectors.

At Daelim Transformer:

• Swift and efficient bid preparation
• Streamlined, end-to-end project management optimized for consistency
• Markedly reduced production and delivery lead times
• Exceptional delivery reliability
• Expedited, standardized documentation
• Punctual, just-in-time delivery

Daelim Transformer stands as a trusted partner, offering innovative and efficient power transformer solutions tailored to meet unique demands.

Design Tools : SOLIDWORKS(3D) / AUTOCAD

Equipment : 3F/2F/1F Multi-winding Transformer / Autotransformer

Standard: ANSI-IEEE /CSA/EN/BS/GOST/AS, IEC

Design: Sealed-tank system /Inert-gas pressure system or conservator-tank system without diaphragm; On load or no load voltage tap changer

Cooling system: ONAN/ONAF/ODAF/OFAF/OFWF/KNAN/KNAF

Insulation: Mineral Oil Inhibited I Not Inhibited I Vegetable oil

Primary voltage: Up to 230kV, up to 900 kV BIL

Capacity:  Up to 270 MVA           Frequency: 50/60 HZ

Suitable for indoor and outdoor application.

Ambient temperature: - 50℃-40℃

Relative humidity: ambient air relative humidity should be below 93%，

Altitude: ≤1000m

Max wind speed:≤35 m/s

Earthquake acceleration: horizontal acceleration ≤0.3g

Vertical acceleration ≤0.15g

Special conditions: customized products are available.

Routine tests, also known as factory tests, are essential for ensuring the quality of every transformer. These tests include:

• Dielectric tests
• Measurement of Voltage Ratio and Vector Group
• Measurement of Winding Resistance
• Separate-Source Power-Frequency Voltage Withstand Test
• Measurement of Bushing Capacitance and Dielectric Dissipation Factor
• Induced Voltage Withstand Test
• Measurement of No-load Losses and No-load Current
• Measurement of Impedance Voltage and Load Losses
• Sealed Test
• Measurement of the winding frequency spectrum response curve
• Current transformer test
• On-Load Tap Changer (OLTC) tests
• Measurement
• Oil test

Type Tests

Type tests verify if a transformer meets specified standards and whether products of the same type or series meet these standards. Type test items include:

• Temperature rise test
• Lightning impulse test

Special Tests

Special tests are conducted as mutually agreed upon by the manufacturer and the user. Special test items encompass:

• Transient voltage transfer characteristics measurement
• Three-phase transformer zero-sequence impedance measurement
• Short-circuit test
• Sound level measurement
• Measurement of harmonic currents during no-load
• Measurement of power consumption by fans and oil pumps

Core Assembly:

The iron core consists of cold-rolled, granular-oriented silicon steel sheets known for their low loss and high magnetic conductivity. These sheets are structured in multiple steps with a complete tilt to minimize both loss and noise. Fixed clamps are applied to the iron core to enhance mechanical strength and reduce leakage losses. The addition of a PET banding structure further reduces noise and ensures the core column's stability.

Coil Winding:

For the high-voltage (HV) winding, the adoption of an entanglement or inner-screened continuous design with a phase insulation structure guarantees robust insulating strength. The medium voltage (MV) and low voltage (LV) windings use high-strength conductors or conductor transposition and incorporate forced cooling to reduce temperature rise and enhance short-circuit resilience. The specific winding construction—whether interleaved, shielded disc, helical, disc, or layer—is selected based on voltage and impulse ratings.

Active Parts Assembly:

The assembly process for active parts involves cold pressing to ensure cleanliness and enhance the reliability of leads. Whole assembled phase insulation is utilized to expedite assembly and guarantee the precise dimension and shape of the insulation structure. High-voltage (HV) leads are fortified with specially molded insulation parts for protection, significantly improving insulating strength and reducing the risk of partial discharges.

Oil Tank:

The oil tank undergoes a three-dimensional finite element strength analysis and employs a Pro-E mold to strengthen its mechanical integrity. Welding methods incorporate automatic submerged arc welding, accompanied by ultrasonic fluorescence leakage testing to ensure a leak-free performance. Stringent quality control is maintained throughout the surface coating process.

Daelim Transformer collaborates with clients to understand their specific transformer requirements and tailors solutions accordingly. Once the exact needs are determined, the company's engineers swiftly recommend the appropriate solutions.

The engineering team has the expertise to meet various performance requirements. This includes enhancing short-circuit strength, upgrading kVA ratings, adjusting voltages, reducing losses, modernizing LTC (Load Tap Changer), reducing sound levels, and modifying the transformer tank.

For technical inquiries, Daelim Transformer's engineering team responds promptly to address questions from both clients and end-users.

Factory-to-Onsite Logistics Support:

The company provides logistical support for safe transportation, utilizing both ships and trucks. Impact recorders are employed to measure and store three-axis impact data, identifying any unusually severe impacts that could potentially damage the transformer during transportation.

On-Site Technical Assistance:

On-site technical support is available, covering assembly, oil treatment, testing, and commissioning (energization), and is conducted by an experienced engineer.

Training:

Factory specialists offer training on transformer operation and maintenance to ensure clients can effectively manage their equipment.

Repair:

Daelim Transformer's technicians are capable of performing various repairs, such as replacing gaskets, broken bushings, and accessories. They can also purify or replace the oil, conduct sanding, priming, and repainting as needed. After repairs are completed, the unit undergoes comprehensive testing to ensure proper functionality.

Power transformers are typically high-voltage transformers known for their substantial size and weight. Daelim Transformer often disassembles various components of the transformer for transportation. The primary transformer unit is typically arranged for transport within an open-top container, while the disassembled components are securely packaged in wooden crates and transported using separate 20 ft/40 ft containers.

Throughout the packaging process, Daelim Transformer pays meticulous attention to numerous details. For example, the control box on the transformer unit is individually encased in a wooden crate to safeguard against potential impacts during transit. Moreover, a protective rain and sun cover is placed above the open-top container to ensure that the transformer unit remains shielded from rain, moisture, and corrosion during transportation.