Documents disponibles écrits par cet auteur

Detection of broken bars in induction motor through the analysis of supply voltage modulation / Nemec, Mitja in IEEE transactions on industrial electronics, Vol. 57 N° 8 (Août 2010) 

Public ISBD [article]  in IEEE transactions on industrial electronics > Vol. 57 N° 8 (Août 2010) . - pp. 2879 - 2888 Titre : Detection of broken bars in induction motor through the analysis of supply voltage modulation Type de document : texte imprimé Auteurs : Nemec, Mitja, Auteur ; Drobnic, Klemen, Auteur ; Nedeljkovic, David, Auteur Année de publication : 2011 Article en page(s) : pp. 2879 - 2888 Note générale : Génie électrique Langues : Anglais (eng) Mots-clés : Fault  diagnosis  Induction  machines  Inverters  Modulation  Predictive  control  Squirrel  cage  motors  Velocity  control Index. décimale : 621.38 Dispositifs électroniques. Tubes à électrons. Photocellules. Accélérateurs de particules. Tubes à rayons X Résumé : This paper presents an application of a novel method for the diagnostics of electric and magnetic asymmetries of rotor cage in induction motor (IM) due to broken rotor bars. An increasing anomaly in magnetic field distribution results in degradation of steady-state and dynamic performance of an IM. This degradation can be determined through the analysis of the average duty cycle of the modulated supply voltage. Broken rotor bars would cause torque and speed ripple which is mitigated by an efficient speed-control algorithm. Consequently, specific oscillation in the duty cycle of the modulated stator voltage appears. This effect can be simply detected without additional hardware and therefore provides a correct evaluation of faulty motor performance, which is a very significant part of condition monitoring and diagnostic procedure in modern supervision systems for electrical drives. DEWEY : 621.38 ISSN : 0278-0046 En ligne : http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5332284 [article] Detection of broken bars in induction motor through the analysis of supply voltage modulation [texte imprimé] / Nemec, Mitja, Auteur ; Drobnic, Klemen, Auteur ; Nedeljkovic, David, Auteur . - 2011 . - pp. 2879 - 2888. Génie électrique Langues : Anglais (eng) in IEEE transactions on industrial electronics > Vol. 57 N° 8 (Août 2010) . - pp. 2879 - 2888 Mots-clés : Fault  diagnosis  Induction  machines  Inverters  Modulation  Predictive  control  Squirrel  cage  motors  Velocity  control Index. décimale : 621.38 Dispositifs électroniques. Tubes à électrons. Photocellules. Accélérateurs de particules. Tubes à rayons X Résumé : This paper presents an application of a novel method for the diagnostics of electric and magnetic asymmetries of rotor cage in induction motor (IM) due to broken rotor bars. An increasing anomaly in magnetic field distribution results in degradation of steady-state and dynamic performance of an IM. This degradation can be determined through the analysis of the average duty cycle of the modulated supply voltage. Broken rotor bars would cause torque and speed ripple which is mitigated by an efficient speed-control algorithm. Consequently, specific oscillation in the duty cycle of the modulated stator voltage appears. This effect can be simply detected without additional hardware and therefore provides a correct evaluation of faulty motor performance, which is a very significant part of condition monitoring and diagnostic procedure in modern supervision systems for electrical drives. DEWEY : 621.38 ISSN : 0278-0046 En ligne : http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5332284

Direct current control of a synchronous machine in field coordinates / Nemec, Mitja in IEEE transactions on industrial electronics, Vol. 56 N° 10 (Octobre 2009) 

Public ISBD [article]  in IEEE transactions on industrial electronics > Vol. 56 N° 10 (Octobre 2009) . - pp. 0278-0046 Titre : Direct current control of a synchronous machine in field coordinates Type de document : texte imprimé Auteurs : Nemec, Mitja, Auteur ; Drobnic, Klemen, Auteur ; Nedeljkovic, David, Auteur Article en page(s) : pp. 0278-0046 Note générale : Génie électrique Langues : Anglais (eng) Mots-clés : Digital  signal  processors  Inverters  Modulation  Synchronous  motor  (SM)  drives Index. décimale : 621.38 Dispositifs électroniques. Tubes à électrons. Photocellules. Accélérateurs de particules. Tubes à rayons X Résumé : This paper presents an implementation of a modified method for direct current control (DCC) in a permanent-magnet synchronous motor (SM). The control is performed using a predictive algorithm in rotor field coordinates due to its simpler implementation. Its task is to minimize the final current error at the end of the sampling interval. Depending on the desired performance, two variants are proposed, yielding either lower switching frequency or lower current ripple. Both variants of DCC, named DCC I and DCC II, have been rearranged for applications in SMs with either surface-mounted permanent magnets or interior (buried) permanent magnets. A comparison with field-oriented control using space-vector modulation and synchronized on/off modulation shows the advantages and drawbacks of the proposed method. Simulations and measurements on a laboratory model with SM having low inductances (thus expecting high ripple) and very high number of poles (high stator supply frequency) confirm the validity of the approach. Additional considerations regarding practical problems, some of which can be found in similar predictive methods, are also presented. DEWEY : 621.38 ISSN : 0278-0046 En ligne : http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5191070 [article] Direct current control of a synchronous machine in field coordinates [texte imprimé] / Nemec, Mitja, Auteur ; Drobnic, Klemen, Auteur ; Nedeljkovic, David, Auteur . - pp. 0278-0046. Génie électrique Langues : Anglais (eng) in IEEE transactions on industrial electronics > Vol. 56 N° 10 (Octobre 2009) . - pp. 0278-0046 Mots-clés : Digital  signal  processors  Inverters  Modulation  Synchronous  motor  (SM)  drives Index. décimale : 621.38 Dispositifs électroniques. Tubes à électrons. Photocellules. Accélérateurs de particules. Tubes à rayons X Résumé : This paper presents an implementation of a modified method for direct current control (DCC) in a permanent-magnet synchronous motor (SM). The control is performed using a predictive algorithm in rotor field coordinates due to its simpler implementation. Its task is to minimize the final current error at the end of the sampling interval. Depending on the desired performance, two variants are proposed, yielding either lower switching frequency or lower current ripple. Both variants of DCC, named DCC I and DCC II, have been rearranged for applications in SMs with either surface-mounted permanent magnets or interior (buried) permanent magnets. A comparison with field-oriented control using space-vector modulation and synchronized on/off modulation shows the advantages and drawbacks of the proposed method. Simulations and measurements on a laboratory model with SM having low inductances (thus expecting high ripple) and very high number of poles (high stator supply frequency) confirm the validity of the approach. Additional considerations regarding practical problems, some of which can be found in similar predictive methods, are also presented. DEWEY : 621.38 ISSN : 0278-0046 En ligne : http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5191070