Electrical motor current signal analysis using a modified bispectrum for fault diagnosis of downstream mechanical equipment
Electrical motor current signal analysis using a modified bispectrum for fault diagnosis of downstream mechanical equipment
复制标题
DOI：
10.1016/j.ymssp.2010.07.004
复制
发表时间：
2011-01-01
影响因子：
8.4
通讯作者：
Ball, A. D.
中科院分区：
文献类型：
--
作者：
Gu, F.;Shao, Y.;Ball, A. D.
本文介绍了基于双谱分析的双级往复式压缩机中感应电机电流的常见故障识别和量化方法。为理解电机在不同故障条件下承受不同负载时电流信号的非线性特性奠定了理论基础。虽然电流信号的传统双谱表示允许包含相位信息和消除高斯噪声，但由于电流信号中边带分量的随机相位变化，它产生不稳定的结果。然后采用基于电流信号的调幅特性的改进双谱来同时组合低边带和高边带，从而更准确地表征电流信号。基于这种新的双谱分析，提出了一种更有效的故障诊断特征，即归一化双谱峰。结合原始电流信号的峰度值，双谱特征产生可靠的故障分类结果。特别是，低特征值可以将皮带松动与其他故障情况区分开来，并且可以使用两个线性分类器轻松区分不同程度的排气阀泄漏和中间冷却器泄漏。该工作为下游驱动设备的电机驱动故障诊断提供了一种新的定子电流分析方法。英国皇家版权所有(C) 2010出版的爱思唯尔有限公司版权所有。
This paper presents the use of the induction motor current to identify and quantify common faults within a two-stage reciprocating compressor based on bispectrum analysis. The theoretical basis is developed to understand the nonlinear characteristics of current signals when the motor undertakes a varying load under different faulty conditions. Although conventional bispectrum representation of current signal allows the inclusion of phase information and the elimination of Gaussian noise, it produces unstable results due to random phase variation of the sideband components in the current signal. A modified bispectrum based on the amplitude modulation feature of the current signal is then adopted to combine both lower sidebands and higher sidebands simultaneously and hence characterise the current signal more accurately. Based on this new bispectrum analysis a more effective diagnostic feature, namely normalised bispectral peak, is developed for fault classification. In association with the kurtosis value of the raw current signal, the bispectrum feature gives rise to reliable fault classification results. In particular, the low feature values can differentiate the belt looseness from the other fault cases and different degrees of discharge valve leakage and inter-cooler leakage can be separated easily using two linear classifiers. This work provides a novel approach to the analysis of stator current for the diagnosis of motor drive faults from downstream driving equipment. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.