Rectifiers can be classified as uncontrolled and controlled rectifiers, and the controlled rectifiers can be further divided into semi-controlled and fully-controlled rectifiers. Uncontrolled rectifier circuits are built with diodes while fully controlled rectifier circuits are built with SCR’s. Both diodes and SCR’s are used in semi-controlled rectifier circuits.

There are several rectifier circuits rectifier configurations. The popular rectifier configurations are listed below.

  • Single phase semi controlled bridge rectifier
  • Single phase fully controlled bridge rectifier
  • Three phase three pulse, star connected rectifier
  • Double three phase, three pulse star connected rectifiers with inter phase transformer (IPT)
  • Three phase semi controlled bridge rectifier
  • Three phase fully controlled bridge rectifier
  • Double three phase fully controlled bridge rectifiers with an inter phase transformer (IPT)

Apart from the configurations listed above, there are series-connected and 12-pulse rectifiers for delivering high power output.

Power rating of a single phase rectifier tends to be lower than 10kW. Three phase bridge rectifiers are used for delivering higher power output, up to 500kW at 500V DC or even more. For low voltage, high current applications, a pair of three phase, three pulse rectifiers interconnected by an inter phase transformer (IPT) is used. For a high current output, rectifiers with IPT are preferred to connecting devices directly in parallel.

There are many applications for rectifiers. Some of these include:

  • Variable speed DC drives
  • Battery chargers
  • DC power supplies and power supply for a specific application like electroplating