35 KV Class Three Phase Distribution Oil Immersed Transformer

What makes the 35 kV Class Three Phase Distribution Oil Immersed Transformer energy-efficient?

The 35 kV Class Three Phase Distribution Oil Immersed Transformer achieves high energy efficiency through its advanced core and coil design. It uses high-grade cold-rolled grain-oriented (CRGO) silicon steel for the core, with a full-miter non-puncture structure that minimizes magnetic circuit gaps, reducing no-load loss by 30% compared to conventional models. The windings are made of high-conductivity oxygen-free copper, lowering on-load loss and improving power transmission efficiency, complying with IE2 energy efficiency standards.

How does the 35 kV Class Three Phase Distribution Oil Immersed Transformer ensure insulation safety at 35 kV?

To meet the strict insulation requirements of 35 kV voltage, the transformer adopts multi-layer high-density insulation paper and vacuum pressure impregnation (VPI) technology, achieving an insulation breakdown voltage ≥65 kV. The core and windings are fully immersed in high-grade 25# transformer oil (breakdown voltage ≥40 kV), which enhances insulation and heat dissipation. Additionally, the tank’s double-sealing structure (fluororubber gaskets + laser welding) prevents moisture ingress, further ensuring insulation stability.

What sealing technology does the 35 kV Class Three Phase Distribution Oil Immersed Transformer use for long service life?

The transformer adopts a fully sealed design with corrugated plate radiators that replace traditional oil conservators. The radiators expand and contract with oil temperature changes, balancing internal and external pressure without air contact, slowing oil aging. All tank joints use high-performance fluororubber gaskets, and key seams are laser-welded to achieve 100% leak-free operation. This design extends the product’s service life to 25+ years with minimal maintenance.

Why is the 35 kV Class Three Phase Distribution Oil Immersed Transformer suitable for large-scale power grids?

With a rated power range of 800 kVA to 31500 kVA, the 35 kV Class Three Phase Distribution Oil Immersed Transformer offers high power supply capacity, ideal for long-distance power transmission in large-scale power grids. Its optimized short-circuit impedance (6-7.58%) ensures stable operation under grid fluctuations, while the high-precision on-load tap changer (±2×2.5%) adjusts voltage dynamically, maintaining output stability for industrial and residential users.

How does the 35 kV Class Three Phase Distribution Oil Immersed Transformer adapt to harsh environments?

The transformer’s tank undergoes three-level anti-corrosion treatment (derusting → phosphating → electrostatic spraying) with a paint layer thickness of ≥120 μm, resisting salt spray, chemical corrosion, and dust. It operates stably in -30℃ to +45℃ ambient temperatures and can withstand seismic intensity 8, making it suitable for coastal areas, desert regions, and mining sites. Optional IP44 protection grade enhances dust and moisture resistance for extreme conditions.

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 Shandong Electric Power Co., Ltd.

Customer Profile: A leading provincial power utility in China, responsible for upgrading the 35 kV transmission network in Jinan to support urbanization and industrial development.
Application Scenario: 35 kV power grid expansion to replace aging transformers and improve transmission efficiency.
Solution: 40 units of 10000 kVA fully sealed transformers with low-loss design and anti-corrosion treatment.
Results: No-load loss reduced by 32%, annual energy savings of ~$680,000; stable operation for 24 months with zero unplanned outages, meeting Shandong’s smart grid standards.

Case 2: Tenaga Nasional Berhad (TNB, Malaysia)

Customer Profile: Malaysia’s national power utility, responsible for power supply for the Kuala Lumpur-Singapore High-Speed Rail infrastructure project.
Application Scenario: 35 kV power distribution for high-speed rail stations and supporting facilities, requiring high reliability and compact design.
Solution: 25 units of 5000 kVA transformers with corrugated plate radiators and compact structure.
Results: Compliant with Malaysian Standard (MS IEC 60076), operated continuously for 18 months without downtime; compact design saved 20% installation space, supporting on-schedule project completion.

Case 3: Saudi Electricity Company (SEC)

Customer Profile: Saudi Arabia’s national power utility, upgrading the 35 kV grid in Riyadh to meet rising industrial and residential power demand.
Application Scenario: Outdoor 35 kV substations in high-temperature desert environments, requiring heat resistance and low maintenance.
Solution: 30 units of 8000 kVA transformers with optimized heat dissipation (enhanced radiators) and salt spray-resistant coating.
Results: Stable operation at 52℃ ambient temperature; maintenance frequency reduced by 60%, meeting SEC’s “low maintenance” requirements; passed SABER certification for market access.

Case 4: Kenya Power and Lighting Company (KPLC)

Customer Profile: Kenya’s national power utility, expanding the 35 kV rural power grid to connect remote villages and agricultural areas.
Application Scenario: Long-distance 35 kV power transmission for rural areas, requiring cost-effectiveness and durability.
Solution: 35 units of 3150 kVA conservator-type transformers with reinforced tank structure and dust-proof design.
Results: Reduced rural grid construction costs by 40%; power supply coverage expanded to 80+ villages; withstood dusty and humid conditions, service life verified to exceed 20 years.

Rated Power (kVA)	Rated High Voltage (kV)	Rated Low Voltage (kV)	Connection Symbol	Short Circuit Impedance (%)	No Load Loss (W)	On-Load Loss (W)	No Load Current (%)	Cooling Mode	Tank Type
800	35/38.5	6.3/6.6	Yd11/Ynd11	6.0	980	9350	1.05	ONAN	Sealed/Conservator
1000	35/38.5/44	10.5/12.47	Yd11/Ynd11	6.0	1160	11500	1.00	ONAN	Sealed/Conservator
2500	35/38.5/44	10.5/13.8	Yd11/Ynd11	6.5	2450	19600	0.75	ONAN/OFAF	Sealed/Conservator
5000	35/38.5/44	10.5/13.8	Yd11/Ynd11	7.0	4270	31200	0.60	ONAN/OFAF	Sealed/Conservator
10000	35/38.5/44	10.5/13.8	Yd11/Ynd11	7.5	8260	45100	0.55	OFAF	Sealed/Conservator
20000	35/38.5/44	10.5/13.8	Yd11/Ynd11	7.58	14100	79100	0.50	OFAF	Sealed/Conservator
31500	35/38.5/44	10.5/13.8	Yd11/Ynd11	8.0	20000	112200	0.40	OFAF	Sealed/Conservator

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, and ANSI C57.12.00 standards, holding CE (LVD/EMC), SGS, RoHS, and ISO 9001 certifications. Regional certifications such as SABER (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.

Yes. We can adjust short-circuit impedance, tap changer range, and voltage levels to match your local grid standards. For extreme environments (high temperature, salt spray, dust), we offer customized anti-corrosion, heat dissipation, and protection grade (IP44/IP54) upgrades.

Compared to 10 kV/20 kV transformers, it has 2-3 times higher power supply capacity, lower line loss in long-distance transmission (reduced by 40-50%), and better adaptability to large-scale power grids. It is designed for high-voltage distribution scenarios such as regional power grids and large industrial parks.

We have technical teams stationed in Southeast Asia, the Middle East, and Africa, offering on-site installation guidance, commissioning, and maintenance. All products come with a 12-month warranty, and we provide lifelong technical support and spare parts supply via global logistics networks.

Routine maintenance is simple: monthly check oil level (conservator type) and operating temperature; quarterly inspect sealing joints for leaks; annually clean radiators (more frequently in dusty areas); hermetically sealed models require no oil replacement under normal operation for 20+ years.

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 insulation levels to match your renewable energy system’s technical requirements.

With high-quality raw materials, advanced production technology, and strict quality control, the designed service life is 25 years. Under normal operation and regular maintenance, the actual service life can extend to 30 years.