Dual Converter with Circulating Current

Dual Converter with Circulating Current

• In this scheme both the converters are turned on simultaneously, the firing angles are adjusted by the control voltage V_C in such a way that (α₁ + α₂) = 180°.
• The average voltage produced by both the converters will be same, but the instantaneous values will be different therefore circulating current will flow.
• The circulating current is limited by a circulating current reactor. The circulating current scheme has following advantages :

Advantages of Circulating Current :

1. Both the converters remain in conduction continuously, irrespective of whether the load current is continuous or not.
2. The load current in the power circuit can flow in either direction, at any time. Thus a reversal of load current is a natural and smooth procedure.
3. The time response is fast if the converters are in continuous conduction.

Disadvantages of Circulating Current :

The disadvantage is that reactor has to be used. The reactors are costly and bulky at high power levels.