سال انتشار: ۱۳۸۴
محل انتشار: هشتمین کنفرانس دانشجویی مهندسی برق
تعداد صفحات: ۷
Aminifar – Electrical Engineering Department IUST (Iran University of Science and Technology)
Saeedfar – Electrical Engineering Department IUST (Iran University of Science and Technology)
This paper describes the case study of the reliability of subtransmission transformers (63/20 Kv) installed in MAZANDARAN province, operated in subtransmission system. The information obtained from Mazandaran Regional Electric Company. Failures of transformers in subtransmission systems not only reduce reliability of power system but also have significant effect on power quality since one of the important components of any system quality is reliability of that system. To enhance utility reliability, failure analysis and rates, failure origin and physical damage causes must be study. The results of study on 60 substation including more than 110 transformers installed in subtransmission system show that the failure mode of transformers can be represented by Weibull distribution. Weibull statistics have been widely used and accepted as a successful mathematical method to predict the remaining life time of any equipment. Analysis show that the protective operation is the highest number of failures but the highest Average Time of Fault (ATF) is related to insulation problems. Useful conclusions are presented both for power systems operators and manufactures for improving the reliability of transformers. The methodology used in this study also applied to other equipment in electrical system such as oil switches, capacitor and insulators.