Comparison of Two-Individual Current Control and Vector Space Decomposition Control for Dual Three-Phase PMSM

The relationship between the two-individual current control and the vector space decomposition (VSD) control for a dual three-phase permanent magnet synchronous machine (PMSM) is investigated in this paper. It is found that the VSD control is more flexible in controlling the fundamental current in alpha beta subplane and the fifth, seventh current harmonics in z(1)z(2) subplane with different proportional and integral (PI) gains, while the two-individual current control is comparable with the VSD control in having the same PI gains in the alpha beta and z(1)z(2) subplanes. It is also found that the two-individual current control may have potential instability issues due to the mutual coupling between the two sets of three-phase windings. If the mutual coupling between the two sets is weak to some extent, then the two-individual current control could have the same dynamic performance as the VSD control without the stability issues. Experiments are conducted on a prototype dual three-phase PMSM to validate the theoretical analysis.