Documents disponibles écrits par cet auteur

Development of anti-icing coatings applied to insulators in China / Xiaoxing Wei in IEEE electrical insulation magazine, Vol. 30 N° 2 (Mars-Avril 2014) 

Public ISBD [article]  in IEEE electrical insulation magazine > Vol. 30 N° 2 (Mars-Avril 2014) . - pp. 42 - 50 Titre : Development of anti-icing coatings applied to insulators in China Type de document : texte imprimé Auteurs : Xiaoxing Wei, Auteur ; Zhidong, Jia, Auteur ; Zhenting Sun, Auteur Année de publication : 2015 Article en page(s) : pp. 42 - 50 Note générale : Génie électrique Langues : Français (fre) Mots-clés : Coating  techniques  Ice  Power  transmission  lines  Silicone  rubber  insulators Résumé : Icing of transmission lines due to extreme weather conditions has caused many failures in power networks worldwide [1]. As China has much of its land 2,000 m above sea level, intense snow and ice storms at this altitude have caused significant losses to the economy, and the harsh conditions have made life very difficult in these regions [2]. The winter of 2008/2009 was particularly harsh with freezing rain, which continued for more than three weeks in the central provinces, causing 218 ice flashovers. In particular, Hunan and Jiangxi Provinces experienced the severest storms resulting in damage to 37% of the 500-kV power transmission towers, collapsing many towers. Considerable work has been done in China on understanding the reasons for, and preventing, the icing flashover of insulators [3]-[10], but in this article the various anti-icing and de-icing methods for insulators currently being investigated in China are discussed with particular reference to the application of semiconductive silicone rubber coatings on insulators. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6749572&filter%3DAND% [...] [article] Development of anti-icing coatings applied to insulators in China [texte imprimé] / Xiaoxing Wei, Auteur ; Zhidong, Jia, Auteur ; Zhenting Sun, Auteur . - 2015 . - pp. 42 - 50. Génie électrique Langues : Français (fre) in IEEE electrical insulation magazine > Vol. 30 N° 2 (Mars-Avril 2014) . - pp. 42 - 50 Mots-clés : Coating  techniques  Ice  Power  transmission  lines  Silicone  rubber  insulators Résumé : Icing of transmission lines due to extreme weather conditions has caused many failures in power networks worldwide [1]. As China has much of its land 2,000 m above sea level, intense snow and ice storms at this altitude have caused significant losses to the economy, and the harsh conditions have made life very difficult in these regions [2]. The winter of 2008/2009 was particularly harsh with freezing rain, which continued for more than three weeks in the central provinces, causing 218 ice flashovers. In particular, Hunan and Jiangxi Provinces experienced the severest storms resulting in damage to 37% of the 500-kV power transmission towers, collapsing many towers. Considerable work has been done in China on understanding the reasons for, and preventing, the icing flashover of insulators [3]-[10], but in this article the various anti-icing and de-icing methods for insulators currently being investigated in China are discussed with particular reference to the application of semiconductive silicone rubber coatings on insulators. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6749572&filter%3DAND% [...]

Evaluation of the degradation of generator stator ground wall insulation under multistresses aging / Zhidong, Jia in IEEE transactions on energy conversion, Vol. 23 n°2 (Juin 2008) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 23 n°2 (Juin 2008) . - pp. 474 - 483 Titre : Evaluation of the degradation of generator stator ground wall insulation under multistresses aging Type de document : texte imprimé Auteurs : Zhidong, Jia, Auteur ; Xiang, Peng, Auteur ; Zhicheng, Guan, Auteur Année de publication : 2008 Article en page(s) : pp. 474 - 483 Note générale : Energy conversion Langues : Anglais (eng) Mots-clés : Weibull  distribution;  ageing;  electric  breakdown;  electric  generators;  machine  insulation Résumé : The actual stator bars of an 18 kV/300 MW generator were used for accelerated multistress aging tests to investigate the degradation of ground insulation. An aging system with combined stresses including thermal, electrical, mechanical vibration, and thermomechanical factors was used to test the aging of stator bar specimens. The nondestructive parameters including partial discharge (PD) quantities and dissipation factor parameters were measured during aging test in order to evaluate the degradation of stator ground wall insulation. At the end of the aging test, an AC breakdown test was performed on the bars in order to obtain the remaining breakdown voltage (BDV) after their nondestructive data had been measured. The changes of nondestructive parameters indicated that the degradation of ground wall insulation. For example, the changes of skewness of indicated the shape of voids in ground insulation changes from flat to narrow, and even exhibits treeing, which is dangerous to insulation because it shortens the effective distance of insulation between high voltage and the ground. The results obtained are summarized as follows. The BDV data fit a Weibull distribution. The correlation between the dissipation factor, the PD parameters, and the breakdown voltage were analyzed, among which the skewness of the average discharge had the most correlation with breakdown voltage. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4505392&sortType%3Das [...] [article] Evaluation of the degradation of generator stator ground wall insulation under multistresses aging [texte imprimé] / Zhidong, Jia, Auteur ; Xiang, Peng, Auteur ; Zhicheng, Guan, Auteur . - 2008 . - pp. 474 - 483. Energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 23 n°2 (Juin 2008) . - pp. 474 - 483 Mots-clés : Weibull  distribution;  ageing;  electric  breakdown;  electric  generators;  machine  insulation Résumé : The actual stator bars of an 18 kV/300 MW generator were used for accelerated multistress aging tests to investigate the degradation of ground insulation. An aging system with combined stresses including thermal, electrical, mechanical vibration, and thermomechanical factors was used to test the aging of stator bar specimens. The nondestructive parameters including partial discharge (PD) quantities and dissipation factor parameters were measured during aging test in order to evaluate the degradation of stator ground wall insulation. At the end of the aging test, an AC breakdown test was performed on the bars in order to obtain the remaining breakdown voltage (BDV) after their nondestructive data had been measured. The changes of nondestructive parameters indicated that the degradation of ground wall insulation. For example, the changes of skewness of indicated the shape of voids in ground insulation changes from flat to narrow, and even exhibits treeing, which is dangerous to insulation because it shortens the effective distance of insulation between high voltage and the ground. The results obtained are summarized as follows. The BDV data fit a Weibull distribution. The correlation between the dissipation factor, the PD parameters, and the breakdown voltage were analyzed, among which the skewness of the average discharge had the most correlation with breakdown voltage. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4505392&sortType%3Das [...]

Laboratory studies of a new stator slot wedge tester for HV generators / Xiang, Peng in IEEE transactions on energy conversion, Vol. 24 N°1 (Mars 2009) 

Public ISBD [article]  in IEEE transactions on energy conversion > Vol. 24 N°1 (Mars 2009) . - pp. 146 - 152 Titre : Laboratory studies of a new stator slot wedge tester for HV generators Type de document : texte imprimé Auteurs : Xiang, Peng, Auteur ; Zhidong, Jia, Auteur ; Shengqiang, Gao, Auteur Année de publication : 2009 Article en page(s) : pp. 146 - 152 Note générale : energy conversion Langues : Anglais (eng) Mots-clés : Digital  signal  processing  chips;  electric  generators;  electric  machine  analysis  computing;  hardware-software  codesign;  machine  testing;  machine  windings Résumé : Stator winding vibration is the most common cause of unexpected failure of high-voltage (HV) generators. Stator bars are generally fixed in slots by using slot wedges and a side packing system. Loose slot wedges could result in excessive vibration of the stator bars, which would accelerate the deterioration of the ground wall insulation. Loose slot wedge testing is consequently one of the most important general examination procedures to make sure the condition of HV generators. The common method used for slot wedge testing is manual measurement, whereby the slot wedge is tapped by hand using a small hammer. A judgment on looseness is made based on the sound from it. A digital signal processor (DSP)-based loose slot wedge tester is described in detail in this paper, including both hardware and software design. It was developed in our laboratory based on the study of slot wedge vibration characteristics in its loosening process. Since embedded software system of the DSP is oriented to a specific industrial field while PC system is of a general purpose, the device has many advantages compared to traditional manual measurement or other slot wedge testing equipment, such as portability, high intelligence, low power consumption, etc. The tester was applied for laboratory loose slot wedge testing of a slot model. The test results soundly verified the good performance of the device. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4749290&sortType%3Das [...] [article] Laboratory studies of a new stator slot wedge tester for HV generators [texte imprimé] / Xiang, Peng, Auteur ; Zhidong, Jia, Auteur ; Shengqiang, Gao, Auteur . - 2009 . - pp. 146 - 152. energy conversion Langues : Anglais (eng) in IEEE transactions on energy conversion > Vol. 24 N°1 (Mars 2009) . - pp. 146 - 152 Mots-clés : Digital  signal  processing  chips;  electric  generators;  electric  machine  analysis  computing;  hardware-software  codesign;  machine  testing;  machine  windings Résumé : Stator winding vibration is the most common cause of unexpected failure of high-voltage (HV) generators. Stator bars are generally fixed in slots by using slot wedges and a side packing system. Loose slot wedges could result in excessive vibration of the stator bars, which would accelerate the deterioration of the ground wall insulation. Loose slot wedge testing is consequently one of the most important general examination procedures to make sure the condition of HV generators. The common method used for slot wedge testing is manual measurement, whereby the slot wedge is tapped by hand using a small hammer. A judgment on looseness is made based on the sound from it. A digital signal processor (DSP)-based loose slot wedge tester is described in detail in this paper, including both hardware and software design. It was developed in our laboratory based on the study of slot wedge vibration characteristics in its loosening process. Since embedded software system of the DSP is oriented to a specific industrial field while PC system is of a general purpose, the device has many advantages compared to traditional manual measurement or other slot wedge testing equipment, such as portability, high intelligence, low power consumption, etc. The tester was applied for laboratory loose slot wedge testing of a slot model. The test results soundly verified the good performance of the device. En ligne : http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4749290&sortType%3Das [...]