Transducer development for nonintrusive load monitoring of rotating machinery

Abstract

Monitoring machine runtime health parameters through nonintrusive means can greatly reduce the up-front time and resource barriers to entry of adding instrumentation to existing plant infrastructure. This work presents the design and evaluation of three transducers as part of a nonintrusive load monitoring system for rotating machinery. Data collected using a custom designed, small-scale induction motor test stand shows the dependence of a large air core RF coil, small RF coil array, and Hall effect sensor outputs on applied motor speeds and mechanical loads (estimated based on generator power). Analysis indicates that the large air core RF coil transducer and the presented method for using nonintrusive collection of induction motor speed and stray flux can statistically measure the difference between any two load points with 95% confidence, if their values differ by 6.6% full scale or greater (±2σ). Additionally, areas of further research toward generalization of the approach are identified.