Simulation and experimental analyses of planetary gear tooth defect using electrical and mechanical signatures of wound rotor induction generators

Abstract

In this paper, the sun gear tooth fault in a one-stage planetary gear is studied in a representative electromechanical system. The aim is to use both electrical and mechanical signatures of a wound rotor induction generator for fault diagnosis through both numerical simulation and experimental approaches. In this regard, a dynamic model of the system, which includes all mechanical components in the drive-train, is presented. It is shown that the sun gear tooth localized fault generates fault impacts at the N×(fs-fc) frequency in the mechanical torque. It is also observed that the most sensitive fault frequency components are close to the main natural torsional resonance frequencies of the mechanical system under study. The simulation results are validated by experiments obtained from a test-rig based upon a 5.5kW wound rotor induction generator which is linked to a one-stage planetary gearbox through mechanical couplings and a high speed shaft. The results demonstrate that the gear tooth localized fault can be detected using both the mechanical torque and the stator current signature of the wound rotor induction generator.