Low computational cost algorithm for detecting rotor asymmetries in IM based on the negative sequence component of the startup currents

Abstract

This paper introduces an algorithm with a very low computational complexity, which enables to detect rotor asymmetries in induction motors. The proposed approach is based on calculating the negative sequence component of the startup stator currents, and enables to visualize the characteristic pattern of the lower sideband component (LSH) during the startup transient. Unlike previous published approaches, the proposed method does not need to use either frequency domain transforms nor time-frequency transforms or complex mathematic functions. Thus it can be implemented as an embedded algorithm in preexisting electronic devices or in low cost devices such as DSPs or tablets. In this paper the method is theoretically justified and validated through simulation and laboratory tests.