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



Battery Cars A to Z

Battery powered cars are a hot topic and widely debated. The pros, cons, issues and time frames can be talked about endlessly. An article by the Telegraph...

Fault Calculations - Typical Equipment Parameters

A frequent problem in fault calculations is the obtaining of equipment parameters.  While it is always preferable to use the actual parameters of the equipment...

Equipment Verification (to IEC Standards)

One of the requirements to ensuring that everything works is to have equipment selected, manufactured and verified [tested] to IEC standards. Not all equipment...

Meeting room of the future

The IET site has a video of a visit showing of a high tech meeting room developed at Napier University in Edinburgh. It a good demonstration of innovative...

Getting Started with Patents

If you have a great idea or invent something the last thing you want is someone to steal the idea. One of the things you can do is protect the intellectual...

How Electrical Circuits Work

If you have no idea how electrical circuits work, or what people mean then they talk about volts and amps, hopefully I can shed a bit light.  I’m intending...

Standard Cable & Wire Sizes

IEC 60228 is the International Electrotechnical Commission's international standard on conductors of insulated cables. Among other things, it defines a...

Tips for a better Low Voltage Protection Discrimination Study

Carrying out a protection system discrimination study is critical to ensure the correct functioning of  the electrical system in the event of faults. ...

Why is electricity so hard to understand?

It's been a busy few months on different projects or busy couple of decades depending on how I look at it. I can say that on the odd (frequent) occasion...

Introduction to Cathodic Protection

If two dissimilar metals are touching and an external conducting path exists, corrosion of one the metals can take place.  Moisture or other materials...

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