An evaluation of the MCSA method when applied to detect faults in motor driven loads

In this paper, an evaluation of the MCSA method when applied to detect faults in motor driven loads is presented. The evaluation is based on transfer functions obtained from small signal model of the induction motor. The inherent behavior of the induction motor as a torque transducer is explored to explain some of the characteristic features of its application to monitoring the driven load connected to its shaft. The influence of the electrical and mechanical parameters on its performance as a load fault detector is investigated. Mathematical relationships among these parameters which allow establish the nature of the frequency response are obtained. It is shown that, although the MCSA (Motor Current Signature Analysis) is a simple and effective method to detect faults on the driven load, care must be taken on its usage. This is due to the non-ideal transducer behavior of the induction motor. Simulation and Experimental results validating the studies are presented.