Construction of Three Phase Transformers

A three-phase transformer is a crucial component in power distribution systems, designed to efficiently transfer and distibut electrical energy between different voltage levels while maintaining high levels of reliability and safety. This article provides a detailed exploration of its construction, highlighting key components and their functions.

Iron Core

The iron core forms the magnetic circuit of the transformer. Constructed from high-magnetic permeability silicon steel sheets, it efficiently converts electrical energy into magnetic energy and vice versa. Structurally, the core supports and secures the windings, ensuring stable operation under varying loads.

Windings

Windings, typically made of copper wire, are fundamental to the transformer's operation. They consist of high-voltage and low-voltage windings wound around the core. These windings establish the magnetic flux necessary for energy transfer and are crucial in determining the transformer's voltage transformation ratio.

Voltage Regulation Devices

Transformers employ voltage regulation devices such as on-load tap changers and off-excitation tap changers. These devices enable adjustment of the transformer's turn ratio, thereby varying the output voltage to meet specific operational requirements without interrupting service.

• On-load Tap Changer: Allows tap changes during operation without disrupting the transformer's load. It ensures precise voltage regulation under varying load conditions.

• Off-excitation Tap Changer: Used for tap changes during transformer shutdown or off-load conditions, facilitating maintenance and adjustment of voltage settings.

You may enjoy: Guide to Tap Changer in Pad Mounted Transformer

Oil Tank

The oil tank serves multiple critical functions in an oil-immersed transformer system:

• Containment: Houses the core and windings, providing physical protection and structural support.

• Cooling Medium: Transformers dissipate heat generated during operation into the surrounding oil, which is circulated through cooling devices.

• Pressure Relief: Equipped with pressure relief devices to safeguard against internal pressure surges caused by faults, preventing structural damage or explosions.

Insulating Oil

High-quality insulating oil, meeting stringent international standards, is used to immerse the windings and core within the transformer. It provides electrical insulation, dissipates heat, and protects against arcing and corona discharge.

Cooling Devices

Efficient cooling is essential for maintaining optimal transformer operation:

• Radiators: Provide natural convection cooling (ONAN - Oil Natural Air Natural) for smaller transformers.

• Coolers: Utilize forced oil circulation (OFAF - Oil Forced Air Forced) or oil-water heat exchange (ODAF - Oil Directed Air Forced) for larger transformers, enhancing cooling efficiency.

Protective Devices

Various protective devices ensure transformer reliability and longevity:

• Gas Relay: Monitors internal gas levels, detecting faults such as overheating or partial discharges, and triggers alarms or disconnection mechanisms.

• Pressure Release Device: Safely vents excess internal pressure during fault conditions, preventing catastrophic failures.

Desiccant

Installed within the transformer's breathing system, desiccants maintain insulating oil quality by absorbing moisture and impurities, preserving transformer insulation performance over its operational life.

Bushings

High and low-voltage bushings provide insulation for lead wires entering and exiting the transformer, ensuring electrical safety and maintaining structural integrity.

More Resource

Guide to Types of High-Voltage Bushings for Pad-Mounted Transformers

Guide to Types of Low-Voltage Bushings for Pad-Mounted Transformers

Conclusion

In conclusion, the construction of the 3 phase transformer integrates advanced engineering principles and robust design elements to ensure reliable energy transmission across power grids. Each component plays a vital role in enhancing operational efficiency, safety, and longevity, meeting the stringent demands of modern electrical distribution systems.

Understanding these components and their functions is crucial for ensuring optimal performance and reliability of three-phase transformers in diverse industrial and utility applications.

Daelim Transformer is a leading manufacturer specializing in a wide range of three-phase transformers, including pad-mount transformers, substation transformers, power transformers, and Tier 2 oil-immersed transformers. Our products are renowned for their high quality and compliance with industry standards such as UL, cUL, CE, FM, and COI certifications. Contact us today to learn more about how our transformers can meet your specific needs.