A carrier-based control scheme for five-leg back-to-back converter-fed induction motor drive

A five-leg back-to-back converter-fed induction motor drive, consisted of coupled rectifier and inverter sharing one leg between them, is discussed in this paper. This topology can be applied for fault-tolerant system when one leg of conventional back-to-back converter fails. However, this kind of system poses a two-object control problem. Moreover, the inherent DC bus voltage distribution between rectifier and inverter limit the performance of system. The poor DC bus voltage utilization of carrier modulation makes the situation worse. A novel zero sequence signal calculation algorithm is presented to achieve independent control of rectifier and inverter and improve the voltage utilization. The simulation is implemented to verify effectiveness of the scheme.