Unsteady characteristics analysis of centrifugal pump operation based on motor stator current

Abstract

Motor current signature analysis technology is a cost-effective, non-intrusive and reliable technique used for monitoring of motor-driven devices. In this method, the motor is regarded as a torque sensor. Theoretical analysis, numerical simulation, and experiment were conducted to do research on time–frequency analysis of current signature for unsteady characteristic extraction of pump operation. Results show that most energy of current is concentrated on the first order of Intrinsic Mode Function (IMF) component. Torque related oscillation could be reflected by energy amplitude and its variation. The root mean square and kurtosis value of transient energy in Hilbert spectrum could be regarded as the indicators of centrifugal pump operation point detection. Hilbert marginal spectrum could depict the stability of centrifugal pump operation and suggest the proper operation points to ensure high efficiency and reliability.