What is a Rectifier Transformer

Rectifiers Transformers are Transformers which have an in-built Rectifier in the secondary side.  The Diodes are mounted inside the Transformer Assembly itself.    The Rectifier Transformer is used in applications which require high DC power such as in DC Traction Systems and in processes such as electrolysis and smelting. 

Voltage regulation is achieved using Tap Changers in the HV side. 

Rectifier Transformers are sometimes also known as Rectiformers. 

Rectifier Transformers are usually connected to a bank.  Each Rectifier-Transformer is designed with an inherent phase shift such that the transformers attain the peak voltage one after another.  This ensures a steady supply at peak voltage.  Thus a system with five banks of rectifier transformers with twelve pulses at a phase shift of +12°, – 6°, 0°, + 6° and +12° will result in a system  with 60 pulses .