DC Chopper

Application

The DC Chopper can be used to control the current and voltage wave form applied to the DC electrode in a DC Electric Arc Furnace

 

DC Chopper Based Power Supply

A DC Chopper based power supply combines a low cost, high reliability diode rectifier with an IGBT based DC chopper output. The IGBT can support fast switching rates, >1kHz, which helps minimise harmonics on the AC supply. By adjusting the time that the IGBT is conducting (T_on/T) a variable DC output can be created.

A single rectifier can feed up to eight choppers to create a single power group as shown below.

 

These power groups can then be fed by phase shifting transformers

 

The resulting solution ensures that the IEEE 519 limits on the incoming grid supply are respected.