Post-Fault Control Technique for Multi-Phase PM Motor Drives under Short-Circuit Faults

In this paper, a post-fault control technique is proposed for multi-phase permanent-magnet (PM) machine drives under short-circuit faults. Purpose of the proposed fault-tolerant control (FTC) is to find a general closed-form solution for healthy phase currents under steady-state post-fault conditions. Healthy phase currents are found through an optimization problem which tries to produce ripple-free output torque with minimum ohmic losses. A five-phase PM machine is used as an example to investigate validity of the proposed solutions through finite-element-analysis (FEA) and experimental tests. Proposed method is a great tool to evaluate fault-tolerant capability of different designs for drive system in terms of maximum available ripple-free torque and power losses. Thanks to its simplicity and flexibility, It is also well-suited for real-time implementation.