Open-Phase Fault-Tolerant Direct Torque Control for Five-Phase Three-Level NPC VSI fed Induction Motor Drive

The important aspect of multiphase machine (MM) drives is the inherent fault-tolerant capability; thus, suitable for most reliable industrial and transportation applications. A faster dynamic response of the electric motor drive can be achieved by using direct torque control (DTC) technique. In this paper, an open-phase fault (OPF) control scheme enabling DTC is proposed for a three-level induction motor drive. The main scope of the proposed DTC technique is needed for interrupt free operation of the FPIM drive even after an OPF occurs. The developed post-fault controller is same for both healthy and post-fault operation (i.e reconfigure-less controller). However, the lookup table developed for both healthy and post-fault operations are different. This is due to the OPF condition has different voltage vectors than the healthy condition. The proposed DTC method is verified by Matlab/Simulink as well as prototype experimental results at steady and transient loading operations.