Multiphase machines for electric vehicle traction

Multi‐phase VSI DC‐link capacitor considerations

“…From (8) and 9, the stored charge in the capacitor within one electrical cycle can be calculated via Coulomb counting of the DClink capacitor current, which results in the voltage ripple:…”

Dual three‐phase permanent magnet synchronous machine investigation for battery electric vehicle power‐trains

“…Multiphase machines have advantages in high power and fault‐tolerance‐drive systems. Recently, the multiphase machines have also attracted attention in electric vehicle applications [2].…”

SVM strategies for multiphase voltage source inverters

“…Electric machine drive systems of different power range have been applied in different fields: hybrid/full electrical vehicles [1,2], aerospace actuators and generation systems [2,3], traction systems on 'more electrical ship' [4,5] and so on. Industrial variable speed, AC electric drive systems have gained application track record over the last 20 years, a market sector that seems to be increasing in size and displacing traditional fixed supply and speed electric drives due to established improvements in drive system energy conversion efficiency and functionality.…”

“…Moreover, even in applications where 3-phase systems are fully capable, the multiphase AC drive system can be competitive and may improve existing systems. The comparisons between normal 3-phase and multiphase machine drive systems indicate that the application of multiphase machine and power electronic inverter can reduce the power handling and hence rating per phase [6], increase the fault tolerance capability [7], and improve the torque output [1]. Detailed comparison between 3-phase and 9-phase brushless permanent magnet (BLPM) machine drive systems [1,8] gives a general view and quantitative analysis and evaluation between them.…”

“…The comparisons between normal 3-phase and multiphase machine drive systems indicate that the application of multiphase machine and power electronic inverter can reduce the power handling and hence rating per phase [6], increase the fault tolerance capability [7], and improve the torque output [1]. Detailed comparison between 3-phase and 9-phase brushless permanent magnet (BLPM) machine drive systems [1,8] gives a general view and quantitative analysis and evaluation between them. Under the conditions that the stator current density and machine geometry are the same, the application of 9-phase BLPM drive system improves the torque capability and torque quality, decreases the iron losses, and the inverter DC-link voltage ripple, thus reducing the drive system smoothing capacitor [8].…”