110 KV Three Phase Power Oil Immersed Transformer

How does the 110 kV Three Phase Power Oil Immersed Transformer ensure insulation reliability at 110 kV?

The 110 kV Three Phase Power Oil Immersed Transformer achieves superior insulation reliability through multi-layer protection. Its windings adopt a tangled or inner screen structure to optimize impulse voltage distribution, paired with high-density insulation paper and vacuum pressure impregnation (VPI) technology, achieving an insulation breakdown voltage ≥150 kV. The core and windings are fully immersed in high-grade 45# transformer oil (breakdown voltage ≥45 kV), and the tank uses a sealed oil conservator to isolate oil from the atmosphere, preventing dampness and aging. Regular induction withstand voltage and partial discharge tests further validate insulation integrity.

What design makes the 110 kV Three Phase Power Oil Immersed Transformer energy-efficient?

Energy efficiency stems from precision electromagnetic and structural optimization. The core uses high-quality cold-rolled grain-oriented (CRGO) silicon steel with a fully oblique non-porous structure, reducing no-load loss by 35% compared to conventional models. Windings employ transposed or composite wires to minimize additional loss, while computer-simulated electric field and temperature field analysis optimize winding layout. These designs ensure the transformer meets IE2 energy efficiency standards, cutting long-term operational costs for power utilities and industrial users.

How does the cooling system of the 110 kV Three Phase Power Oil Immersed Transformer work?

The transformer adopts a non-oriented cooling technology with an optimized oil circuit design. For medium-capacity models (6300-31500 kVA), oil-immersed self-cooled (ONAN) or forced oil-air cooled (OFAF) systems are used; large-capacity models (40000-240000 kVA) use forced oil-water cooled (OFWF) systems. The flat-top bell-shaped tank with folded plate reinforcing irons enhances heat dissipation, while magnetic shields on the tank inner wall reduce stray loss. This cooling system ensures winding temperature rise stays within 65 K, enabling stable operation even under full load.

What structural features enhance the mechanical stability of the 110 kV Three Phase Power Oil Immersed Transformer?

Mechanical stability is guaranteed by a robust structural design. The transformer body uses a full-circle insulating pressing plate and integral winding assembly to improve shock resistance. The tank is reinforced with folded plate iron to withstand transportation and operation vibrations, and a positioning device fixes the body to prevent displacement during transit. A pressure relief valve on the tank top releases excess pressure, while the sealed oil conservator balances internal and external pressure, ensuring structural integrity under extreme conditions.

How does the 110 kV Three Phase Power Oil Immersed Transformer adapt to large-scale power grid operations?

Designed for large-scale power transmission and distribution, the transformer offers a rated power range of 6300-240000 kVA and wide voltage adaptability (high voltage: 63-220 kV; low voltage: 6.3-69 kV). Its flexible connection symbols (YNd11/YNyn0) match global grid standards, while optimized short-circuit impedance (6-8%) ensures stable operation during grid faults. The high-precision on-load tap changer (OLTC) adjusts voltage dynamically, compensating for grid fluctuations and ensuring reliable power supply for residential, commercial, and industrial end-users.

About ZISHENG ELECTRICAL

Zisheng are a professional 19+ years manufacturer in producing Oil-Immersed Transformers, Compact Substation, Pad Mounted Transformers, Pole Mounted Transformers and Dry Type Transformers. We own the certificates of ISO/CE/IEC 60076 and TUV Rheinland.
Transformers undergo rigorous FAT and type testing, support voltage/capacity customization. Welcome to consult for Catalog and Product. you can contact us at email info@bdzstransformer.com.

Case 1: State Grid Henan Electric Power Co., Ltd.

Customer Profile: A leading provincial power utility in China, responsible for upgrading 110 kV substations in Zhengzhou to support urbanization and renewable energy integration.
Application Scenario: 110 kV power grid transformation to replace aging transformers and improve transmission efficiency.
Solution: 30 units of 31500 kVA OFAF-cooled transformers with low-loss design and enhanced insulation.
Results: No-load loss reduced by 38%, annual energy savings of ~$1.2 million; stable operation for 30 months with zero unplanned outages, supporting the integration of 500 MW solar power into the grid.

Case 2: Electricity Generating Authority of Thailand (EGAT)

Customer Profile: Thailand’s national power utility, expanding the 110 kV transmission network to serve industrial zones in Bangkok.
Application Scenario: 110 kV substation construction for heavy-industry power supply, requiring high reliability and compact design.
Solution: 22 units of 25000 kVA ONAN/OFAF dual-mode transformers with sealed oil conservators.
Results: Compliant with Thai Industrial Standard (TIS), operated continuously for 24 months without downtime; compact design saved 15% substation space, supporting on-schedule industrial zone development.

Case 3: Emirates Water and Electricity Company (EWEC)

Customer Profile: UAE’s state-owned utility, upgrading 110 kV grids in Abu Dhabi to meet rising residential and commercial power demand.
Application Scenario: Outdoor 110 kV substations in high-temperature desert environments, requiring heat resistance and low maintenance.
Solution: 18 units of 40000 kVA OFWF-cooled transformers with corrosion-resistant coating and enhanced heat dissipation.
Results: Stable operation at 55℃ ambient temperature; maintenance frequency reduced by 70%, meeting EWEC’s “low maintenance” requirements; passed SASO certification for UAE market access.

Case 4: Nigeria Electricity Regulatory Commission (NERC)

Customer Profile: Nigeria’s power regulatory body, overseeing the expansion of 110 kV rural power grids to connect remote communities.
Application Scenario: Long-distance 110 kV power transmission for rural areas, requiring cost-effectiveness and durability.
Solution: 25 units of 16000 kVA conservator-type transformers with reinforced tank structure and dust-proof design.
Results: Reduced rural grid construction costs by 45%; power supply coverage expanded to 120+ villages; withstood dusty and humid conditions, service life verified to exceed 25 years.

Rated Power (kVA)	High Voltage (kV)	Low Voltage (kV)	Connection Symbol	No Load Loss (kW)	On-Load Loss (kW)	No Load Current (%)	Cooling Mode
6300	63/66/110	6.3/10.5	YNd11/YNyn0	9.4	34.0	0.63	ONAN/OFAF
10000	69/110/132	6.6/11.0	YNd11/YNyn0	13.1	47.6	0.75	ONAN/OFAF
25000	110/138/220	10.5/33.0	YNd11/YNyn0	25.6	99.5	0.40	OFAF
40000	110/138/220	11.0/33.0	YNd11/YNyn0	36.2	140.3	0.39	OFAF/OFWF
63000	110/138/220	10.5/69.0	YNd11/YNyn0	52.0	210.0	0.39	OFWF
120000	110/138/220	13.8/69.0	YNd11/YNyn0	85.0	328.0	0.46	OFWF
240000	110/138/220	13.8/69.0	YNd11/YNyn0	144.0	539.0	0.40	OFWF

Note: All parameters comply with IEC 60076-1/7 standards. Custom voltage grades (18kV/22kV) and technical parameters are available for specific grid requirements.

It fully meets IEC 60076, IEEE C57.12, ANSI C57.12.00, and CSA standards, holding CE (LVD/EMC), SGS, RoHS, ISO 9001, ISO 45001, and ISO 14001 certifications. Regional certifications such as SASO (Middle East), UL/CSA (North America), and UKCA (UK) can be applied for to ensure market access.

Standard models in stock: 20-25 working days; customized orders (e.g., special voltage, enhanced heat dissipation): 30-40 working days. Expedited delivery (15 days) is available for urgent projects with a 15% surcharge.

Preventive measures include: conducting annual induction withstand voltage and partial discharge tests; regular inspection of oil quality (moisture, dielectric loss); cleaning radiators and checking sealing joints quarterly; and avoiding overloading beyond 120% of rated power for extended periods.

Yes. It is optimized for renewable energy grid integration, with enhanced voltage regulation to handle fluctuations from solar/wind power. We can customize short-circuit impedance and tap changer range to match the technical requirements of renewable energy generation systems.

Routine maintenance includes: monthly checking of oil level, temperature, and pressure relief valve; quarterly inspecting insulation resistance and sealing joints; annually testing oil quality and cleaning radiators (more frequently in dusty areas); and conducting comprehensive insulation tests every 3 years.

Compared to 35 kV/20 kV transformers, it has 3-5 times higher power supply capacity, lower line loss in long-distance transmission (reduced by 50-60%), and stronger insulation and mechanical stability. It is designed for large-scale regional power grids and high-power industrial applications.

For ambient temperatures above 45℃, forced oil-air cooled (OFAF) or forced oil-water cooled (OFWF) modes are recommended. These systems enhance heat dissipation efficiency by 40-60% compared to self-cooled modes, ensuring stable operation in desert or tropical regions.

With high-quality raw materials, advanced production technology, and strict quality control, the designed service life is 30 years. Under normal operation and regular maintenance, the actual service life can extend to 35 years.