Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników
Powiadomienia systemowe
  • Sesja wygasła!
  • Sesja wygasła!

Znaleziono wyników: 5

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  ceramic material degradation
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
The paper presents results of investigation of microstructure and micro-hardness for material of ZnO varistors applied to 110 kV surge arrester and surge arrester counter. The research combined two pairs of varistors, each consisted of one varistor subjected before to operation, while the other one was brand new unit and constituted a reference. All varistors were made of the same material by the reputable manufacture. The tests revealed a different degree of the material degradation for varistors subjected before to operation. This also refers to different degradation mechanism observed for the material of these varistors, if typical effects of degradation of aged ZnO varistors were considered as a reference. Physical state of spinel in the microstructure had a significant impact on the material degradation, however a considerable loosening of the microstructure associated with bismuth oxide was observed too. It was surprising, since the precipitates of the bismuth oxide phase most often showed very good binding to the ZnO matrix and high resistance to associated electrical, thermal and mechanical effects. The degradation effects in the ZnO matrix proved to be limited only.
EN
The paper presents investigations of microstructure of varistors of damaged surge arrester counters. A similar ZnO varistor, not subjected before to operation, was a point of reference in this research. The results of investigations of the ZnO varistors show an untypical phase composition of their material, which was characterized by unsatisfying homogeneity and cohesion. The degradation processes of varistor material in the subsequent stages were recognized and described. A harmful impact of humidity inside the untight surge arrester counter on its operation and its ZnO varistors was proved. Some conclusions being the result of the operation checking of surge arrester counters were presented too.
PL
W pracy przedstawione zostały doświadczenia z eksploatacji liczników zadziałań, które stanowiły inspirację do badań pochodzących z nich warystorów ZnO. Badana była mikrostruktura elementów pochodzących z uszkodzonych liczników zadziałań. Odniesienie stanowił analogiczny warystor, z licznika który nie był w eksploatacji. Badania wykazały nietypowy skład fazowy tworzywa badanych warystorów oraz niską jednorodność i spoistość ich czerepu. Opisano i udokumentowano procesy degradacji tworzywa o zróżnicowanym nasileniu. Wykazano szkodliwy wpływ wilgoci we wnętrzu rozszczelnionego licznika zadziałań na jego funkcjonowanie, w tym na umieszczone w nim warystory ZnO. Przedstawiono ponadto wnioski dotyczące kontroli eksploatacyjnej liczników zadziałań.
EN
The paper presents experience from exploitation of surge arrester counters. There was documented destructive influence of humidity inside the untight surge arrester counter on its operation and ZnO varistors within. There were presented examinations of microstructure of varistors of damaged surge arrester counters. A point of reference was similar ZnO varistor, not subjected to operation before. Investigations revealed that material of varistors had an untypical phase composition and was characterized by unsatisfying homogeneity and cohesion. There were recognized and described the subsequent stages of the degradation processes of varistors material. Conclusions resulting from the operation checking of surge arrester counters were also presented.
EN
The paper presents the test results for the microstructure of ZnO varistors comprising high voltage gapless surge arresters. The tests were performed on varistors produced in different periods and by various manufacturers. The research was inspired by different characteristics of changes in values of current flowing through surge arresters as a function of changes in values of system voltage in a 220 kV substation, and the temperature in a multi-year cycle. Furthermore, the effects of varistor microstructure degradation following a failure of an unsealed surge arrester were investigated. The results provided the grounds for assessment of ZnO varistor microstructure parameters in terms of their durability and resistance to degradation processes.
PL
W artykule przedstawiono wyniki badań mikrostruktury warystorów ZnO, wchodzących w skład beziskiernikowych ograniczników przepięć wysokiego napięcia. Badania obejmowały warystory wykonane w różnych okresach i przez różnych producentów. Inspiracją do podjęcia badań były różniące się charakterystyki prądów płynących przez ograniczniki w funkcji napięcia systemu w rozdzielni 400 kV oraz temperatury, w cyklu rocznym. Ponadto badane były efekty degradacji mikrostruktury warystorów po awarii rozszczelnionego ogranicznika przepięć. Uzyskane wyniki dały podstawę do oceny parametrów mikrostruktury warystorów ZnO z punktu widzenia ich trwałości i odporności na procesy degradacji.
EN
The article presents the results of investigation of microstructure and degradation of ZnO varistors of the high voltage surge arresters. The research included varistors made at different times and by different manufacturers. The inspiration to undertake the study were differing characteristics of currents flowing through the limiter as a function of surge voltage system of 400 kV and temperature on an annual basis. In addition, there were studied the effects of the microstructure degradation of the varistors from the surge arrester after the breakdown. The results gave the basis for the evaluation of the microstructure parameters of the ZnO varistors from the point of view of their durability and resistance to degradation processes.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.