Unity power factor thyristor rectifier recent developments

This paper highlights the concept of current injection in a three phase ac dc converter and discusses its advancements over the years. The inconveniences of passive approaches like the bulky delta-wye transformer as the medium of current injection is looked into, and an active method is proposed not only for diode, but also for thyristor rectifier. This method is based on a set of bi-directional static witches between the dc bus and the ac supply. This makes the entire topology lightweight and efficient. Further enhancements are also carried out in the current shaping network in order to make the scheme effective over a wide output voltage variations