Investigation of the influence of open-phase faults on noise and vibrations of switched reluctance machines

Switched reluctance machines (SRMs) benefit from simple and cheap design and inherent fault tolerance, but still suffer from torque ripple and noise, vibration and harshness (NVH) issues. This paper experimentally investigates the influence of an open-phase fault on a 15 kW 8/6 SRM in terms of NVH and torque ripple by comparing run-ups with and without fault. The use of speed-frequency plots allows for an easy distinction between speed orders and structural resonances. Results show that even speed orders are amplified and damped in the vibration and sound-pressure-wave measurements in faulty and healthy conditions respectively. At low speeds, the sixth speed order also appears in the torque, due to the non-activation of one phase. This order however tends to disappear at high speed, due to the filtering effect of the mechanical inertia of the test bench.