Fault tolerant control of a seven-phase drive by degrees of freedom adaptation

This paper proposes a simple way to control multi-phase drives in open-phase conditions. Contrary to existing methods, current references are not recomputed and the control scheme is kept the same to run in open-circuited phase condition. In order to work in fault-conditions, the number of degrees of freedom of the control scheme is adapted to the number of degrees of freedom of the drive. Since a particular attention has to be dedicated to the structure and controller tuning, harmonic content of induced perturbations in fault mode is exhibited. Simulation and experimental results are presented to show the effectiveness and the limitations of the proposed method.