Short-Circuit Fault-Tolerant Operation of Modular and Reconfigurable Six-Phase PMSM Drive

초록

Electric drives in transportation systems require high reliability, demanding exceptional dependability, resilience, and fault-tolerant operational capabilities. Among the various motor faults, winding short-circuit (SC) faults are particularly severe, as they can result in high temperatures, excessive torque ripple, and dragging torque, potentially triggering cascading failures, such as fires, irreversible magnet demagnetization, and flux saturation. To address these challenges, various fault-tolerant control strategies and drive topologies employing phase and drive redundancy have been proposed. However, the existing methods often experience significant performance degradation and increased losses under fault conditions. This article introduces a modular and reconfigurable fault-tolerant operation method using three two-phase inverter modules. By reconstructing phase currents from the back electromotive force (EMF), it enables to compensate current signals and fault-tolerant operation under single or two SC fault conditions. The analytical details of the approach are provided, supported by validation through simulations and experimental results. The proposed method effectively minimizes torque ripple and power losses while maintaining consistent mechanical output during postfault operation. It is particularly suitable for safety-critical applications, where maintaining rated torque or output power is essential under fault scenarios.

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