Sliding-mode control of a six-phase series/parallel connected two induction motors drive

• A configuration is proposed for parallel connection of two quasi six-phase IMs (QIMs) to achieve an intrinsic decoupling, like previous series connections.
• A robust nonlinear controller is employed for each SIM. The effectiveness and capability of the proposed controller are illustrated by practical results.
• The proposed controller is used for a two quasi six-phase series/parallel connected IMs drive system to compare these connections under the same conditions.
• For the first time the operation of series/parallel connections is shown under the conditions that one motor is controlled in the closed-loop system and one motor in the open-loop system.

In this paper, a parallel configuration is proposed for two quasi six-phase induction motors (QIMs) to feed them from a single six-phase voltage source inverter (VSI). A direct torque control (DTC) based on input–output feedback linearization (IOFL) combined with sliding mode (SM) control is used for each QIM in stationary reference frame. In addition, an adaptive scheme is employed to solve the motor resistances mismatching problem. The effectiveness and capability of the proposed method are shown by practical results obtained for two QIMs in series/parallel connections supplied from a single VSI. The decoupling control of QIMs and the feasibility of their torque and flux control are investigated. Moreover, a complete comparison between series and parallel connections of two QIMs is given.