Application of online voltage mismatch condition monitoring of induction motor stator windings in a mining environment

Previous theoretical and laboratory research has demonstrated the utility of using voltage mismatch predictors for online condition monitoring of induction motor stator windings. However, the use of this monitoring system in a mining or other industry application depends upon the ability to determine motor impedance parameters prior to the onset of winding deterioration. Since these impedance parameters depend upon the motor speed, such evaluations require the collection of voltage and current data over a range of operating speeds. In addition, a sufficient amount of natural or created voltage unbalance is required in order to evaluate these parameters. The investigation presented in this paper uses duplicate data-collection and evaluation setups in both an operating mine and in the laboratory in order to obtain a better understanding of the voltage variations that are required for determination of the motor impedance parameters. Results are then related to the feasibility of applying voltage mismatch condition-monitoring procedures in an operating mine.