Current progressive balancing of three phase converter operating with unbalanced grid

The paper deals with the current progressive balancing from the target of constant p or constant q component of instantaneous power to symmetrical current target. Referenced current imbalance depends on the operation mode and whether the current reaches the limit. The fixed p component of power is selected for the inverter operation mode. The fixed q component of power is selected for the rectifier operation. In both targets, the current is sinusoidal, however unbalanced. It does not provide the maximum possible power transfer available at given voltage imbalance. The maximum power can be reached at sinusoidal current. Thus in the case in which the current vector length reaches instantly the maximum value, the current is progressively balanced to increase the value of transferred power. Symmetrical components decomposition based proposed control provides management of the semiminor and semi-major axes of elliptical hodograph of unbalanced.