Abstract
Fractional-slot concentrated winding interior permanent magnet (FSCW-IPM) machines have been designed with very low winding mutual inductance for magnetic isolation features required for improving their fault-tolerant capabilities. These magnetically-isolated FSCW-IPM machines no longer adhere to the preconditions required for a conventional abc-to-dq0 transformation. As a result, it is found in this paper that $\boldsymbol {d}-/\boldsymbol{q}$ . -axes could couple with 0-axis in magnetically-isolated FSCW-IPM machines. Considering the 2nd-order reluctance component, this phenomenon leads to 3rd-harmonic injection in phase voltages during normal operation, which can be cancelled out in terms of line-to-line voltage for Y-connected three-phase system. For post-fault operation of a three-phase FSCW-IPM machine with winding neutral return path, 0-axis current is non-zero, resulting in the 3rd and 5th harmonic injection in phase voltages. Study shows that the amplitudes of those extra harmonics are determined by both saliency ratio and 0-axis current. For field-oriented control during post-fault operation, the bandwidth of the PI current regulator as well as switching frequency should be carefully determined to be able to take into account the major harmonics injected in phase voltages. Co-Simulation that links the finite element model with the control algorithm has been carried out to show the impact of this phenomenon.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
