Tel: +86-513-88779999
Email: [email protected]
Tel: +86-513-88779999
Email: [email protected]
DINGXIN delivered an SCZB18-16000/35/10.5 kV dry-type three-phase transformer with on-load tap changing and Class 1 energy efficiency.
DINGXIN has successfully completed and shipped an SCZB18-16000/35/10.5 kV three-phase dry-type on-load tap-changing transformer for a major project in Hezhou, Guangxi, China.
The transformer has a rated capacity of 16,000 kVA, a 35 kV primary voltage, and a 10.5 kV secondary voltage. It is equipped with an on-load tap changer to support voltage regulation without taking the transformer out of service for each tap adjustment.
The transformer was developed for an application in which power continuity, voltage stability, fire safety, and energy efficiency are essential.
With its large capacity, dry-type construction, on-load voltage regulation, and Class 1 energy-efficiency design, the unit provides a dependable power-conversion solution for critical project loads.
The project required a large-capacity transformer capable of supplying important loads that could not be routinely interrupted for voltage adjustment.
The principal technical requirements included:
At 16,000 kVA, the transformer must carry substantial winding current and withstand significant electromagnetic forces during abnormal system conditions.
Increasing capacity also creates additional thermal and mechanical challenges, including:
DINGXIN needed to optimize the transformer’s core, windings, insulation, cooling ducts, supports, and enclosure interfaces as one coordinated system.
The 35 kV primary system requires carefully controlled electrical clearances and insulation coordination.
The design had to consider:
For a large dry-type transformer, controlling the manufacturing process is particularly important because winding casting quality, conductor positioning, insulation interfaces, and assembly accuracy can directly influence partial-discharge performance.
The project includes important loads that require a high level of supply continuity.
With a de-energized tap changer, the transformer must be isolated before its tap position can be changed. This can interrupt the connected system or require a separate transfer arrangement.
The SCZB18-16000/35/10.5 kV transformer therefore uses an on-load tap-changing system. The tap changer can adjust the transformer ratio while the transformer is carrying load, helping maintain the 10.5 kV output within the required operating range as the incoming voltage or load condition changes.
On-load tap changing does not guarantee that the entire electrical system can never experience an outage. However, it avoids the routine shutdown required solely for tap adjustment and therefore supports better power continuity.
The project required a transformer solution suitable for an application with strict fire-safety expectations.
Unlike a conventional oil-immersed transformer, a dry-type transformer does not contain a large volume of flammable mineral insulating oil. This helps reduce risks associated with oil leakage, oil contamination, and oil-fed fire.
Dry-type construction does not make an electrical installation completely fireproof. Appropriate protection, ventilation, temperature monitoring, installation clearances, and fire-safety measures remain necessary.
A 16,000 kVA transformer may remain in service for long operating periods, so relatively small differences in losses can create significant lifecycle energy costs.
To meet the project’s Class 1 energy-efficiency target, DINGXIN optimized:
The objective was to reduce both no-load and load losses without compromising insulation, temperature rise, mechanical strength, or reliability.
DINGXIN developed the transformer specifically around the 16,000 kVA capacity, 35/10.5 kV voltage ratio, on-load regulation requirements, and dry-type installation conditions.
The core and winding system was designed to balance efficiency, voltage regulation, thermal performance, impedance, and short-circuit withstand capability.
The engineering team optimized conductor sections, winding geometry, insulation distances, cooling ducts, and structural supports to control losses and temperature rise under rated operating conditions.
The transformer is equipped with an on-load tap changer that changes the effective number of primary winding turns while the transformer remains energized and loaded.
This allows the unit to respond to variations in incoming voltage or system load and helps stabilize the 10.5 kV secondary supply.
The tap changer can be coordinated with a voltage-control system according to the approved project design. Manual, local automatic, or remote-control functions may be configured according to the final technical requirements.
The transformer uses a dry-type insulation system rather than a large volume of liquid insulating oil.
This configuration offers several advantages for suitable installations:
A large-capacity dry-type transformer requires effective heat dissipation.
DINGXIN optimized the air passages within and around the windings to improve cooling performance. The transformer can be equipped with winding-temperature sensors, a digital temperature controller, alarm contacts, trip signals, and forced-air cooling.
When the winding temperature or operating load reaches a configured threshold, the ventilation system can be activated to increase airflow and enhance heat removal.
The final operating strategy is determined by the project design, transformer rating, enclosure, ambient conditions, and approved temperature limits.
Before shipment, the transformer underwent the specified manufacturing inspections and factory tests.
The inspection scope included applicable items such as:
Following completion of the required inspections and confirmation that the transformer met the agreed delivery conditions, the unit was prepared, loaded, and shipped to the project site in Hezhou, Guangxi.
The on-load tap changer allows the voltage ratio to be adjusted while the transformer is carrying load. This helps avoid an outage solely for changing the tap position.
For continuous industrial processes and other important loads, this capability can improve operational flexibility and supply continuity.
When the incoming 35 kV supply or connected load changes, the tap changer can adjust the transformer ratio within its specified range.
This helps maintain a more stable 10.5 kV output for downstream equipment.
The dry-type design eliminates the large volume of mineral insulating oil found in conventional oil-immersed transformers.
This reduces the risk of oil leakage and oil-fed fire, making the transformer suitable for projects with demanding fire-safety and environmental requirements.
The Class 1 energy-efficiency design reduces transformer losses.
For a 16,000 kVA unit operating over many years, lower losses can provide meaningful energy and operating-cost savings.
The transformer’s electromagnetic, insulation, thermal, and structural systems were designed around its large capacity and operating conditions.
This helps the equipment withstand demanding service while supplying major project loads.
The SCZB18-16000/35/10.5 kV dry-type on-load tap-changing transformer has been successfully completed and shipped to the project site.
The delivery represents another important milestone in DINGXIN’s development of large-capacity dry-type transformers for critical power applications.
DINGXIN will continue to support the project according to the agreed service scope, including technical documentation, installation guidance, commissioning assistance, and after-sales technical support.
The challenge was not simply to manufacture a 16,000 kVA transformer. The project required DINGXIN to balance large capacity, 35 kV insulation, on-load voltage regulation, dry-type fire safety, Class 1 energy efficiency, thermal management, and supply continuity.
Through project-specific electromagnetic design, optimized windings, an on-load tap-changing system, and comprehensive temperature-control provisions, DINGXIN delivered a transformer solution suited to the operational demands of the major Hezhou project.
Looking for a large-capacity dry-type transformer with on-load voltage regulation? Contact DINGXIN with your capacity, voltage, load, installation, efficiency, and delivery requirements.
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