Control of a three-phase converter under unbalanced input voltage conditions using invert sequence d-q representation

The mathematical model of a three-phase voltage source converter has been developed in the synchronous frames of the reference for positive sequence component. Also there have achieved some controlled method based on the model recently. In this paper, an invert sequenced d-q representation was presented. With the representation, positive dq component and negative dq component in a three-phase system can be divided easily with a low-pass filter and used in a feedback stage. And with a resonant loop controller input current can be controlled. So the representation is useful in an unbalanced system.