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 .