Acoustic monitoring of stator winding delaminations during thermal cycling testing

2010 ◽  
Vol 17 (5) ◽  
pp. 1405-1410 ◽  
Author(s):  
H. Zhu ◽  
D. Kung ◽  
M. Cowell ◽  
S. Cherukupalli
2020 ◽  
Vol 12 (1) ◽  
pp. 53-64
Author(s):  
Kukuh Widodo ◽  
Muhamad Haddin ◽  
Gunawan Gunawan

ABSTRACT The arise of partial discharge in isolation of the winding stator generator is thing that general because existence ageing and excessive stress. Partial discharge in isolation of the winding stator occur in the core slot area or endwinding area. The problem that occur in isolation of the winding stator generator is the presence of corona and high partial discharge in the endwinding area caused by ineffective monitoring of partial discharge. This research discusses about that occurrence corona and partial discharge, and the effectiveness of repairing insulation of the stator winding that performed during overhaul. The analysis methods used is comparative, characteristics and trending, and linear regression to predict the age of operation worthiness in isolation of the winding stator. The results of the analysis showed that, the cause of corona and high partial discharge due to damage to the isolation surface consequence contamination from bearing seal oil which have seepage and load & thermal cycling, with the age of operation worthiness shortest isolation of the winding stator during ± 2 years 1 month 21 days or only increased 14 days after overhaul.   Keywords : partial discharge, corona, linear regression, age of worthiness isolation of the winding     ABSTRAK Timbulnya partial discharge pada isolasi belitan stator generator merupakan hal yang umum terjadi karena adanya penuaan dan tekanan yang berlebih. Partial discharge pada isolasi belitan stator terjadi di area slot inti atau area endwinding. Permasalahan yang terjadi pada isolasi belitan stator generator adalah adanya korona dan partial discharge tinggi pada area endwinding yang disebabkan karena kurang efektifnya monitoring terhadap partial discharge. Penelitian ini membahas tentang terjadinya korona dan partial discharge, serta efektifitas perbaikan isolasi belitan stator generator yang dilakukan saat overhaul. Metode analisa yang digunakan adalah komparasi, karateristik dan trending, serta regresi linear untuk memprediksi usia kelayakan operasi isolasi belitan stator. Hasil analisa menunjukkan bahwa, penyebab terjadinya korona dan partial discharge tinggi karena adanya kerusakan pada permukaan isolasi akibat kontaminasi minyak dari seal oil bearing 5 yang mengalami rembesan dan load & thermal cycling, dengan usia kelayakan operasi tersingkat isolasi belitan stator selama ± 2 tahun 1 bulan 21 hari atau hanya mengalami kenaikan 14 hari setelah overhaul.   Kata kunci : partial discharge, korona, regresi linear, usia layak isolasi belitan


2013 ◽  
Vol 311 ◽  
pp. 467-471
Author(s):  
Chao Ming Hsu ◽  
Ah Der Lin ◽  
Tsung Pin Hung ◽  
Wen Chun Chiu ◽  
Jao Hwa Kuang

The effects of isothermal aging and the thermal cycling loading on the shear toughness of different solder materials and ball sizes have been explored. The difference between shear toughness values of traditional Sn/37Pb eutectic solder ball joints and the lead free Sn/3.0Ag/0.5Cu solders are chosen for discussion. The experiment measurements under the ball shear test (BST) have been compared and studied for both solder joints. The fracture behaviors of the solder joints under the high temperature aging and thermal cycling testing are examined by scanning electron microscope (SEM). The variation of shear toughness of different ball joints reveals that the high temperature aging and thermal cyclic loading reduce the shear toughness significantly. The measured shear toughness values indicate that the Sn/3.0Ag/0.5Cu solder joints have better ductility for the joints undergoing the high temperature aging and the thermal cycle loadings. Based on the measured results, the better reliability for the Sn/3.0Ag/0.5Cu ball joints is expected, due to the aging and cycling load testing.


2021 ◽  
Author(s):  
Bart Vandevelde ◽  
Chinmay Nawghane ◽  
Riet Labie ◽  
Ralph Lauwaert ◽  
Daniel Werkhoven

Abstract SnBi based solder alloys become an interesting alternative for standard SnAgCu as they can be used to solder components at much lower temperature. The typically 50°C lower solder reflow temperature is less damaging for PCB and components, and also prevents hot tear and head-in-pillow failures for large fine pitch BGA components. A reasonable concern for these low-melting temperature solders is the thermal cycling reliability performance, in particular for harsh conditions such as automotive products. In this work, thermal cycling testing and failure analysis have been performed on 9 × 9 mm size QFN components and large chip components (2010 and 2512) which are typically sensitive to thermal fatigue. The results are benchmarked to standard SAC alloy. Also the process advantages from the low temperature solder alloys are depicted in this paper. Finally, the effect of Pb contamination on this SnBi based solder is investigated.


2018 ◽  
Vol 340 ◽  
pp. 17-24 ◽  
Author(s):  
J. Gonzalez-Julian ◽  
T. Go ◽  
D.E. Mack ◽  
R. Vaßen

2021 ◽  
Vol 63 (3) ◽  
pp. 272-278
Author(s):  
Matthias Friedlein ◽  
Daniel Gräf ◽  
Jonas Stegner ◽  
Jörg Franke

Abstract Receptacle contacts often are a weak spot of the reliability in electronic systems. During the application phase of the lifecycle, especially in the automotive wiring harness, connectors experience severe loads such as temperature changes. During qualification testing, accelerated tests simulate these thermal stresses. Yet, only the damage mechanisms relevant for service life must be triggered. However, the increasing complexity of electronic components and wiring harnesses demands a continuous adaptation of test strategies. Therefore, this study develops and applies application-oriented load profiles for thermal qualification testing of connectors. Experiments include load profiles inspired by seasonal changes and daily car usage. The tests are carried out on a relative movement test bench as well as in a thermal cycling testing chamber. Contact resistance progression curves, the surface roughness of the contacts, and the area of the stressed contact zones assist in evaluating the effectiveness of the load profiles. All contacts tested during relative movement experiments show no change in contact resistance. The thermal cycling load profile however results in a significant rise in contact resistance. Additionally, the roughness values show varying damages on the contacts due to the different load profiles.


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