Discerning mechanical load unbalances from rotor faults in induction machines through current space vector components

Abstract

Low frequency load torque oscillations and rotor faults have similar effects on stator current spectral contents of induction machines. Intensive researches efforts have been spent with the aim of separating them through Motor Current Signature Analysis (MCSA). So far, however, the proposed techniques are impractical because they need an accurate estimation of the machine parameters. In this paper a procedure to discern the two kinds of events, based on the unique features of the current space vector, is proposed. By this procedure, MCSA can be safely used to diagnose rotor faults.