Harmonic current generation mechanism and harmonic current suppression method of DTP-PMSG

The dual three-phase permanent magnet synchronous generator (DTP-PMSG) has a promising application in aircraft starter-generator system. However, the electromagnetic coupling existing between the dual three phases causes current harmonics, which poses a difficult problem for the highly dynamic voltage stabilisation control of the DTP-PMSG. In this paper, a maximum four-vector space vector pulse width modulation (SVPWM) algorithm is proposed based on vector space decoupling (VSD) control to achieve harmonic current suppression in DTP-PMSG systems. Firstly, the mathematical model of the DTP-PMSG is established using both the double d-q decoupling method and the VSD method. On this basis, the coupling mechanism of DTP-PMSG is clarified, and the harmonic current generation mechanism of DTP-PMSG is revealed. Meanwhile, this paper analyses in detail the types of harmonic currents caused by different asymmetry types. Subsequently, the maximum four-vector SVPWM algorithm is introduced in this paper, which achieves the effect of harmonic current suppression by simultaneously performing closed-loop control of the currents in the d-q axis and z1-z2 axis. Then, the simulation models of the two control methods are built. Finally, the effectiveness of the maximum four-vector SVPWM algorithm based on VSD transformation for harmonic current suppression is validated through simulation comparison and analysis.