ON-LINE ROTOR FAULT DIAGNOSIS WAY BASED ON SPECTRUM ANALYSIS OF INSTANTANEOUS POWER IN SQUIRREL CAGE INDUCTION MOTORS
LIU Zhen-xing1,2, YIN Xiang-gen1, ZHANG Zhe1, LIU Hui-kang2 (1. Huangzhong University of science and Technology, Wuhan 430074,China; 2. Wuhan University of science and Technology, Wuhan 430081, China)
In this paper, a new approach based on spectrum analysis of the instantaneous power is proposed to on-line detect mixed rotor fault (broken rotor bars and eccentricity) in squirrel cage induction motors. The instantaneous power is the product of a sampled line voltage and the corresponding line current. Compared with the familiar way based on spectrum analysis of the stator line current, the proposed approach can get rid of the interference to the fault related characteristic components from the fundamental component, and highlight fault characteristics, and separate mixed faults,which is useful to the quantification of the fault extent and establishment of diagnostic rules. The validity of this approach has been verified by theoretical analysis and experimental results.