Statistical approach to discharge bearing currents

被引:7
作者
Smolenski, Robert [1 ]
Kempski, Adam [1 ]
Bojarski, Jacek [2 ]
机构
[1] Univ Zielona Gora, Inst Elect Engn, Zielona Gora, Poland
[2] Univ Zielona Gora, Div Stochast Proc & Probabil Theory, Zielona Gora, Poland
关键词
Electromagnetism; Bearings; Electric current; Electric discharges; INVERTER; MOTOR; MACHINES; EMI;
D O I
10.1108/03321641011028233
中图分类号
TP39 [计算机的应用];
学科分类号
081203 ; 0835 ;
摘要
Purpose - The purpose of this paper is to propose a statistical approach, which enables the prediction of the risk of the appearance of discharge bearing currents in a given drive that can damage the motor bearings. Using such an approach, the drives for the decisive but expensive, long-term destructive investigations can be selected. A comparative analysis is presented to show the applicability of the presented statistical model. Design/methodology/approach - In the paper, a statistical approach to large data sets of measured bearing currents is presented. Weibull distribution has been chosen to describe the amplitudes of bearing currents, whereas exponential distribution is used for the approximation of the awaiting times to puncture. In order to check the hypothesis that these distributions are independent two tests has been conducted: F-Snedecor, to check equality of mean values and Bartlett's to check variance equality. On this basis, joint distribution is expressed as the product of independent marginal distributions. Findings - The comparative analyses show that special caution is required for a proper selection of EMI filters. The additional inductance of the filter in a common mode (CM) current path decreases the damping factor of the circuit and significantly increases the risk of bearing damage caused by electric discharge machining currents. The CM transformer is a cheap and effective solution that reduces CM current without increasing the rate and the amplitudes of bearing currents. Originality/value - This paper presents a new approach to bearing currents that allows prediction of the risk of bearing damage in a given drive.
引用
收藏
页码:647 / 666
页数:20
相关论文
共 18 条
[1]   A passive EMI filter for eliminating both bearing current and ground leakage current from an inverter-driven motor [J].
Akagi, Hirofumi ;
Tamura, Shunsuke .
IEEE TRANSACTIONS ON POWER ELECTRONICS, 2006, 21 (05) :1459-1469
[2]  
[Anonymous], 2005, Testing Statistical Hypothesis
[3]   Experience with variable-frequency drives and motor bearing reliability [J].
Bell, S ;
Cookson, TJ ;
Cope, SA ;
Epperly, RA ;
Fischer, A ;
Schlegel, DW ;
Skibinski, GL .
IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, 2001, 37 (05) :1438-1446
[4]   Scaling effects of inverter-induced bearing currents in AC machines [J].
Binder, Andreas ;
Muetze, Annette .
IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, 2008, 44 (03) :769-776
[5]  
BUSSE DF, 1997, IEEE T IND APPL, V33, P766
[6]  
CHEN S, 1996, IEEE T IND APPL, V32, P21
[7]  
Jameson E., 2001, Electrical Discharge Machining
[8]   Statistical model of electrostatic discharge hazard in bearings of induction motor fed by inverter [J].
Kempski, A ;
Smolenski, R ;
Bojarski, J .
JOURNAL OF ELECTROSTATICS, 2005, 63 (6-10) :475-480
[9]   Capacitively coupled discharging currents in bearings of induction motor fed from PWM (pulsewidth modulation) inverters [J].
Kempski, A .
JOURNAL OF ELECTROSTATICS, 2001, 51 :416-423
[10]  
KEMPSKI A, 2002, IEEE PESC, V3, P1551