Rotor torsional resonance detection in induction drives by MCSA focused on rotor slot harmonics
Torsional resonances may incur in induction drives due to large harmonic torques produced by the inverter. The torsion can affect the rotor-load system, but more sneaky resonances may arise in the rotor end-rings of fabricated-cage induction motors. Abnormal cage torsions may lead to bar breakage due to high-cycle fatigue. Since the high-frequency speed oscillations are difficult to detect, torsional resonances may go unnoticed and lead to drive fault on the long run.