What is a rectifier transformer? 

By on


ABB Rectifier Transformer

I've recently come across this question a couple times browsing the internet. Decided to give a quick answer here.

A rectifier transformer is a transformer which includes diodes or thyristors in the same tank. Voltage regulation may also be included. Rectifier transformers are used for industrial processes which require a significant direct current (dc) supply. Typical processes would include dc traction, electrolysis, smelting operations, large variable speed drive trains, etc.

The application for which the transformer is used, will drive the design considerations including:

  • bridge type connection of the thyristors for higher voltages
  • interphase connection for low voltage, high current applications
  • number of pulses (6, 12 and higher with phase shifting)
  • eddy current and harmonic issues

Voltage regulation is achieved with no-load or on-load tap changers on the high voltage side. Fine levels of voltage regulation can be achieved using saturable reactors on the secondary side. Regulation units may be built in or separate.

If anyone has any comments or rectifier transformer experience to share, please add it below.



Steven McFadyen's avatar Steven McFadyen

Steven has over twenty five years experience working on some of the largest construction projects. He has a deep technical understanding of electrical engineering and is keen to share this knowledge. About the author

myElectrical Engineering

comments powered by Disqus

  1. amsh's avatar amsh says:
    5/17/2013 6:04 PM

    Thanks for sharing the information. Can you please explain the harmonic issues and eddy currents?


Comments are closed for this post:
  • have a question or need help, please use our Questions Section
  • spotted an error or have additional info that you think should be in this post, feel free to Contact Us



Harmonised Cable Codes and Colours

Within Europe the European Committee for Electrotechnical Standardization (CENELEC) has standardised the both the designation and colour of cables.   ...

UPS Sizing - Rules of Thumb

It wasn't so long ago I was telling someone that I don't use rules of thumb as most things are easily calculated anyhow.   As it turns out I last week...

Mobile Phones (Brick to Implant)

The mobile phone was born in 1973. They were the size of a brick and weighed a couple of kg, making them difficult to fit into your pocket. At a few thousand...

Bows and Arrows

It starts with me reading one of the Horrible History books with my son (Groovy Greeks). Arrows were mentioned which lead to the discussion of the bodkin...

Famous Scientists

Here’s list of some famous scientists. Deliberately short, with the aim to provide a quick memory jog or overview. If your looking for more detailed information...

IEC 61439 - The Switchgear Standard

The new standard IEC 61439 replaces the old 60439. Compared to the old standard, the new 61439 is a more clearly defined and takes into account the assembly...

Lead us, Warleader

Delum, who had watched all in silence, his face empty of expression, now spoke in turn. ' "Lead us, Warleader, into glory."' Reading is something I do...

Lightning Risk Assessment (IEC 62305)

IEC 62305 'Protection against lightning' requires a risk assessment be carried out to determine the characteristics of any lightning protection system...

Cables for MV Power Distribution - Earthed versus Unearthed Systems

Power cables can basically be classified into earthed and unearthed cables, where earthed and unearthed refer to the application for which the cable is...

Star-Delta Motor Starting - Performance

Many questions sent in to the site are in connection with motor starting and in particular star-delta.  For all but the simplest application, there is...

Have some knowledge to share

If you have some expert knowledge or experience, why not consider sharing this with our community.  

By writing an electrical note, you will be educating our users and at the same time promoting your expertise within the engineering community.

To get started and understand our policy, you can read our How to Write an Electrical Note