On-line dead-time compensation method for dual three phase induction machine using harmonic sub-space component

Dead-time compensation has always been an important issue in pulse-width-modulation-based voltage source inverter. For a dual three phase induction drive system with two sets of three phase stator windings spatially shifted by 30 electrical degrees, the stator resistance and leakage inductance are the only 5th and 7th harmonic impedance. As a result, the current distortion caused by dead-time becomes more apparent than the three phase induction machine and thus dead-time compensation more important. In this paper, the dead-time model for dual three phase induction is introduced by the vector decomposition method. And a dead-time online compensation method based on the harmonic sub-space component of this model is proposed. By the comparison between the current before and after the compensation, the effectiveness of this method is validated.