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This paper proposed a novel PV faults diagnosis method, which is based on the structure of differential power processing (DPP). Since the conventional PV faults diagnosis methods are very easily affected by the working environment conditions, such as solar irradiance and temperature. Compared to the conventional methods, this method is able to diagnose several PV modules at the same time. Furthermore,...
Increasing I/O counts have led to ever decreasing cross sectional contact areas or, by default, an increase in solder performance expectations. A recognized measure of solder joint integrity is gained through High Speed Shear testing, (HSS). This article will statistically evaluate the solderability of the dominant final finishes with reference to some real life variables. The only skew is that only...
A methodology for lifetime testing of lithium-ion batteries in small SOC intervals is presented. The specific test procedure and level of control is important in producing reliable data. The methodology offers high precision without increasing the test duration. The duration time can be reduced with up to 50%, by ensuring more continuous cycling and by reducing the number of performance tests.
Short-term DC progressive-stress tests on 200 micron thick specimens of a commercial XLPE and its silica nanocomposite intended for DC use have shown that the DC nanocomposite has a considerably higher breakdown strength than the AC XLPE. However, constant-stress tests have shown that both the nanocomposite and the unfilled XLPE have similar lifetimes at medium fields of 125–175 kV/mm. There is also...
This Transformer experiences aging everyday as it gets older. The aging of transformer can be detected by assessing the condition of its oil insulation. Every transformer has its own aging rate which is influenced by many factors. This paper discusses about effects of lifetime and loading factor on DGA using regression linear method. 219 sample data including DGA and transformer age were collected...
Since 2010, Canadian Blood Services has been modernizing its facility infrastructure. Current plans call for the amalgamation of production sites in the Prairie region by 2019. Under this plan existing production centres in Alberta and Saskatchewan will be consolidated into a single site in Calgary. Because of the potential impact to the distribution network, a simulation model of the logistics network...
In this work, we have used nanoindentation methods to explore the creep behavior, and aging effects of SAC305 solder joints at several elevated testing temperatures from 25 to 125 oC. A special high temperature stage and test protocol was used within the nanoindentation system to carefully control the testing temperature, and make the measurements insensitive to thermal drift problems. Solder joints...
The mechanical behavior of lead free solders is highly dependent on the testing temperature. Previous investigations on mechanical characterization of conventional and doped lead free SAC solders have mainly emphasized stress-strain and creep testing at temperatures from 25 to 125 °C. However, solders are exposed to very high temperatures from 125–200 °C in several harsh environment applications including...
Elderly care is one of the important issues in the medical mature of the time facing all over the world. Currently, the paper-based testing and recording methods are commonly used in various care centers which not only waste manpower but also may cause mistakes with different social workers in assessment. This study aims at measuring the cognitive function of elderly by the empirical research approach...
Isothermal aging of lead-free Sn-Ag-Cu (SAC) solder joints leads to growth of intermetallic (IMC) particles in the solder bulk as well as growth of intermetallic layers at the joint interfaces with copper bond pads. Fracturing near the interfacial IMC layers is often found to be the primary reason for failures caused by drop impacts. The IMCs in SAC joints are primarily AgsSn and Cu6Sn5 binary compounds...
Negative bias temperature instability (NBTI) and positive bias temperature instability (PBTI) cause SRAM stability degradation during its lifetime. Hence, some of the SRAM cells that are functional initially may fail due to aging after usage. This causes field failures of the shipped chips. In this paper we focus on screening out these SRAM cells which may fail after aging during post-fabrication...
This insulation maintenance guide is applicable to rotating electric machines rated from 35 kVA and higher. The procedures detailed herein may also be useful for insulation maintenance of other types of machines.
Human age estimation is an important research topic and can find its applications in such as commodity recommendation and security monitoring. The establishment of existing estimators basically follows a same pipeline, i.e., an estimator is built from a given training dataset like FG-NET and then evaluated on a holdout testing set to determine its effectiveness. In doing so, a usually-followed assumption...
This insulation maintenance guide is applicable to rotating electric machines rated from 35 kVA and higher. The procedures detailed herein may also be useful for insulation maintenance of other types of machines.
Real handwriting authentication systems need a robust writer identification over a long time period. The paper analyzes signature sessions of the ATV-Signature Long Term Database (ATV-SLT DB). The database contains 6 sessions generated by 27 users over 15 month. The quality change of the verification results over a period of 15 month is examined. 64static and dynamic biometric features from the ATV-SLT...
Recently authors have proposed damage equalization method with step-stress tests for quick estimation of life exponent of power equipment insulation. Traditional constant-stress accelerated ageing tests for insulation are disadvantageous since outliers in sample data will always be there and some samples may not fail even after a long time. Such long duration life estimation tests are a major bottleneck...
Much about insulation aging has been understood, thus leading to complex physical life models. However, for design and testing purposes of power insulation, more pragmatic phenomenological models are often used, first of all the so-called “Inverse Power Model”, also referred to as “V-t characteristic”. Yet, the Inverse Power Model is sometimes misused and misinterpreted, not only in technical-scientific...
The welding inspector ensures the integrity of weld joints since the structural stability mainly depends on it. Welded joints are tested for the prediction of remaining useful life using different Non Destructive Testing (NDT) schemes such as Ultrasonic Testing (UT). In this proposed study, possible classification of UT signals acquired from weld areas in terms of different levels of thermal fatigue...
ECAs are nowadays used as a lead-free replacement for solders. They are used in microelectronics for packaging, bonding of surface mount devices, in flip chip and in ball grid arrays and in LCD screens. Benefits of ECAs over solders include lower temperature and simpler processing, environmental friendliness, finer pitch and lower thermomechanical stresses. However, ECAs have higher overall electrical...
Insulation in electrical equipment is a very crucial aspect while designing any electrical system especially in case of high voltages in any part of a power system. Hence it is crucial to determine the properties and performance of an insulating material. The experiments deal with the measurement of breakdown voltages and determination of ageing of an insulating material under accelerated AC fields...
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