Dry Type Converter transformer with single phase interphase reactor
At Varelen, we specialize in custom-designed transformers for complex power conversion systems. One of our recent solutions is a dry type converter transformer built for an AC–DC 6-pulse rectifier system. This design is particularly effective for 6-pulse rectifier systems, where stable DC output and harmonic mitigation are critical.
At Varelen, we develop custom-engineered converter transformers that meet the most demanding industrial requirements, combining precision winding technology with robust insulation systems and optimized circuit topology.
dry type converter transformer is a specialized transformer designed to supply rectifier systems that convert AC power into DC. Unlike oil-immersed units, it uses solid insulation systems (such as epoxy or cast resin) and operates safely without liquid coolant.
Key characteristics:
Designed for AC–DC conversion in industrial power systems.
Provides galvanic isolation between grid and rectifier.
Ensures voltage adaptation for semiconductor devices.
Safer for indoor or sensitive environments thanks to its dry insulation.
This type of transformer is widely used in industrial drives, electrolysis plants, DC power supplies, and renewable energy converters.
| Feature | Specification |
|---|---|
| Transformer Rating | 100KVA to 25MVA |
| Voltage | 10KV, 0.196kV, 0.341kV |
| Frequency | 50Hz |
| HV winding | cast resin |
| LV winding | VPI |
| Cooling | ANAN , Natural Air / Forced Air (optional) |
| Phase | three Phase |
| Vector group: | Y/y0nr/y6nr |
| Ambient | -45 + 40℃ |
| Altitude | 1000M |
| Reactors | Detuned / Line / Load Reactors as required |
| Electrostatic earth screen | With electrostatic earth screen between HV and LV coil |
| Protection Enclosure | IP00- IP54 , (IP54 Dust- and Splash-Proof) |
| Application | VFD, Renewable Energy, Mining, Data Centers, Rail |
The single-phase interphase reactor (IPR) plays a critical role in multi-pulse rectifier systems. Its primary function is to:
Equalize current sharing between the parallel arms of the rectifier.
Reduce circulating currents and improve DC output stability.
Limit harmonics introduced into the grid.
Enhance voltage utilization in DC circuits.
vacuum pressure impregnation (VPI) technology for the common medium- and low voltage applications. Dry-type reactors are fundamental components in the power quality management, losses reduction, cost alignment and signal shaping could be translated in an overall cost reduction for the equipped applications.
IP54-protection enclosure ensures:
Dust protection
Water protection
Durability
Safety compliance
Customers gain several advantages from this packaged solution:
Compact design: Transformer and reactors in one enclosure reduce footprint.
Improved power : Reactors limit harmonics, improve voltage stability, and protect sensitive loads.
High safety and reliability
• Rigorous climatic, environmental and fire safety testing confirms optimal
performance even in harsh conditions (min -50 ºC & 95% humidity)
• <5pC to reduce the insulation ageing due to electrical field
Environmental adaptability: IP54 protection ensures reliable performance in demanding climates.
Easy to installation and transporation
For 6-pulse rectifier systems, the double reverse star (DRS) configuration is a proven topology. Here’s why:
Phase Shifting: Provides a controlled phase displacement between two secondary windings, helping reduce certain harmonic orders.
Harmonic Reduction: Minimizes distortion fed back to the AC supply.
Improved Output: Produces a smoother DC waveform when combined with the interphase reactor.
Load Balancing: Ensures more uniform stress on semiconductor devices.
This topology is especially effective when high reliability and grid compliance are priorities.
Dry type converter transformers with interphase reactors are widely applied in:
Variable Speed Drives (VSDs): For motors in mining, steel plants, and heavy industry.
Electrolysis Processes: Supplying stable DC for chemical production.
High-Power Rectifiers: In traction, DC substations, and renewable energy converters.
Industrial DC Supplies: For testing systems, furnaces, and manufacturing lines.
Every project is unique, and so is every transformer we build. At Varelen, we:
define voltage, power, and harmonic performance according to custoemr requirements.
Offer both standard and customized winding connections for rectifier applications.
Integrate single-phase interphase reactors optimized for load balance.
Test each transformer to international standards for safety and performance.
This solution is ideal for drives, rectifiers, and DC power supplies where efficiency and reliability are non-negotiable.
At Varelen, we combine precision winding technology, advanced insulation systems, and customized design to deliver transformers tailored to your application.
