Varelen is designing and manufacturing specialtype transformers with over 35 years of experience and with its own know-how, Varelen transformers are working more than 65 countries all around theworld. Vareln offers reliable converter and rectifier transformers for industrialand marine applications with short lead times and with excellent quality.
Converters causes a lot of harmonic frequencies. Therefore, standard distribution or power transformers , do not generally work satisfactorily inconverter application.
Why choose Varelen converter transformer?
1. Varelen can design and manufactured : 6 pulse, 12 pulse , 18 pulse, 24 pluse, 48pulse .
2. Varlen is able to manufacture oil flled ( Mineral, Midel, FR3, Silicone, etc.) or dry type ( cast-resin or varnish impregnated,)
Oil Filled Converter and Rectifer Transformers. Varelen is able to manufacture transformers with different cooling types and differenttank constructions aceording to customer needs,
3. Tank Constructions:
Breathing Type with Conservator
Hermetically Sealed Type with corrugated tank
Hermetically Sealed Type with Nitrogen Blanket
4. Surface Treatment: Varelen is able to manufacture transformers for all around the world, that means.we consider the surface treatment requirements ofdifferent climates. We areable to manufacture transformers with surface treatment, C3 (Standard), C4 and C5.
| Coating Grade |
Corrosion Protection Level |
Typical Environment |
| C3 |
Standard |
Indoor or mild outdoor |
| C4 |
High |
Coastal or industrial |
| C5 |
Very High |
Marine or offshore |
We are ready to apply your paint color request for the converter transformers. (Our Standard: RAL 7033)
Varelen Manufactures converter transformers for application:
- Drives Induction Furnaces
- Rolling Mills
- Paper Mills
- Pumps Propulsion Systems
- Variable-Speed Drives (VSD)
The Advantages of 12-Pulse Phase-Shifting Design
The 12-pulse converter transformer is a widely adopted design for high-performance rectifier systems. It uses two secondary windings—each feeding a 6-pulse rectifier bridge—with a 30° phase shift between them.
a. Harmonic Reduction
The phase shift between the two secondary windings cancels out lower-order harmonics (such as the 5th and 7th), significantly reducing total harmonic distortion (THD). This results in cleaner power and less stress on the power network.
b. Improved Power Factor
Reduced harmonic content enhances the system’s power factor, lowering losses in both transformer and cables. This contributes to higher energy efficiency and lower operational costs.
c. Smoother DC Output
With 12-pulse rectification, the DC waveform exhibits lower ripple, providing more stable output voltage for sensitive loads, such as electrolytic cells or precision drive systems.
d. Less Filtering Requirement
Because of reduced harmonics, the size and cost of AC and DC filters are minimized. This makes the system design more compact and economical.
At Varelen, we also offer 24-pulse and 36-pulse configurations for even higher harmonic suppression, depending on the customer’s rectifier topology.
Our compact and low-weight transformers fully comply with the customers’ specifications. The high quality of our reliable products provides an outstanding capacity to withstand short circuits. Special type tests and quality control ensure safe operation while Varelen’s product support and service network guarantee free and easy use of the products.
The rectifiers used in low voltage are usually both 6- pulse or 12-pulse rectifiers, and they may be diode bridges orthyristor bridges .The 6-pulse rectifier is supplied bya two-winding transformer and the 12-pulse rectifier needs a three-winding transformer, having two separate secondary windings with 30° phase shift.
Especially with higher ratings, a higher converter pulsenumber is needed to limit the network harmonic distortionto an acceptable level.Pulse numbers higher than 12 require special phase shifting; multi-winding transformers or several transformers with phase shifts running inparallel.
Nowadays the pulse number of a converter system can beup to 48. This requires in total eight phase-shifted transformer windings supplying the converter system
From 6-pulse to 48-pulse configurations, Varelen provides custom-engineered solutions for electrolysis, rolling mills, propulsion systems, and renewable energy. Every transformer is a testament to our engineering expertise, strict quality control, and commitment to energy efficiency.
