Electrical Failure Modes Research Articles

Simulation-based optimization of workforce configuration for multi-division maintenance departments

The configuration of human resources in a production company that determines the number of employees at different technical or nontechnical competencies engaged in various operational tasks should be constructed to meet the task requirements above pre-specified expectation levels. Human resource requirements show variation depending on the divisional structures within an organization and their operational dependencies and priorities. A maintenance facility is generally recognized as one of the most labor-intensive divisions in any production company. It employs several workers with diverse technical skills to ensure machinery reliability and availability targets in line with the production plans. The current research study aims to develop a continuous-event simulation algorithm to optimize the maintenance crew configuration and allocation decisions for production companies where different clusters of failure modes are available for multi-equipment operations. This algorithm also simultaneously evaluates the reallocation of the occupied crew for other overlapping maintenance tasks that require similar technical competency. Accordingly, each maintenance division with varying personnel numbers is authorized to maintain particular failure modes. The developed model was implemented for the maintenance department of a surface coal mine where five excavators exposed to diversified random failures are employed. The model input dataset covers three years of maintenance records classified into mechanical and electrical failure modes. The simulation outcomes reveal that the cumulative indirect and direct costs can be minimized for a crew configuration including six electricians and four mechanics.

Study on the electrical breakdown failure mode transition of TSV-RDL

This study investigates the electrical breakdown failure modes and mechanisms of TSV-RDL (Through-Silicon Via with Redistribution Layer) structures through experiments and finite element simulation analysis. By employing a Taguchi method-based finite element simulation, the impact of structural parameters on the electrical breakdown failure modes of TSV-RDLs has been explored. The study reveals two electrically induced breakdown failure modes for TSV-RDLs. One case involves failures occurring at the RDL_pad/SiO2 interface, while the other involves failures within the SiO2 layer along the TSV sidewall interface. The design of TSV-RDLs can influence the distribution of electric field strength and subsequently lead to different electrical breakdown failure modes. In the case of double-blind solid TSV-RDLs, double-through solid TSV-RDLs, and double-blind hollow TSV-RDLs, the pad pitch is identified as a crucial parameter that affects their failure modes. As the pad pitch increases, the location of electrical breakdown failure shifts from the RDL_pad/SiO2 interface to the SiO2 layer along the TSV sidewall interface. Conversely, for the double-through hollow TSV-RDL structure, the structural parameters of TSV, including TSV height, TSV pitch, and SiO2 layer thickness, are the principal factors influencing its failure modes. As these parameters decrease, the position of electrical breakdown failure transitions from the RDL_pad/SiO2 interface to the SiO2 layer along the TSV interface.

Electrical Failure Mechanism in Stretchable Thin-Film Conductors.

Stretchable thin-film conductors are basic building blocks in advanced flexible and stretchable electronics. Current research mainly focuses on strategies to improve stretchability and widen the range of applications of stretchable conductors. However, stability should not be neglected, and the electrical failure mode is one of the most common stability issues that determines the current range and duration in a circuit. In this work, we report the electrical failure mechanism of stretchable conductors. We find a special failure mode for the stretchable conductors, which can be attributed to the coupling effect between local thermal strains and dynamic resistance changes of the thin film. This creates a vicious circle that significantly differs from traditional conductors. Physical parameters related to this special failure mode are investigated in detail. It is found that this mechanism is applicable to different kinds of stretchable conductors. Based on this finding, we also explore methods to modulate the failure of stretchable conductors. The failure mechanism found here provides a fundamental understanding of the current effect of stretchable circuits and is crucial for designing stable stretchable bioelectrodes and circuits.

Fuzzy - Based Multi - Criteria Decision Support System for Maintenance Management of Wastewater Treatment Plants

Abstract Wastewater treatment plants (WWTPs) contain a large number of components, and these components in turn require a large number of maintenance activities and high costs. In this paper, a Fuzzy-based Multi-Criteria Decision Support System (FBMCDS) model was designed based on the failure mode and effect analysis FM-EA and applied to the Rustumiya Project (RP) in Iraq. Information of the RP’s components, failure modes, applied maintenance activities and costs were collected from the documented data, site visit and face-to-face interviews as well as opinions of 44 experts. Through applying the fuzzy logic to analysis the failure modes and effects, the risk priority index (FMRPI) and total intensity (FMTI) of each failure mode ware computed. Thus, maintenance priorities and weights of the RP’s failure modes were specified. In addition, the best maintenance plan was specified based on the FMRPI-FMTI diagram that shows the importance and the type of maintenance required for each failure mode. Failure of the submersible pump has the first rank in terms of priority, while the last priority was occupied by the building failure mode, where the mechanical failure modes are of the highest importance, followed by the electrical failure modes. Finally, the construction failure modes are ranked last due to the small probability of failure. The designed model is considered an efficient tool due to the similarity of the results with the reality of the situation and the ease of reading and displaying the results. In addition, this model can be applied to other projects such as water treatment plants and irrigation projects.

Electrical Reliability and Bending Test Methodologies of Metal Electrode on Flexible Substrate.

To develop highly reliable flexible electronics, mechanical reliability during mechanical deformation such as repeated bending is an important issue. Bending test methodologies to estimate long-term reliability during repeated mechanical deformation are attracting substantial interest from related researchers and industry insiders. In this study, four representative bending test methodologies for testing flexible electronics are introduced: free arc bending test, variable radius bending test, sliding plate test, and variable angle test. Correct name and characteristics of each method are also explained. Furthermore, electrical reliability of Cu film on polymer substrate samples was investigated in each bending test method through in situ monitoring of electrical resistance. With different bending test methodologies, different electrical resistance changes were observed. Fatigue damages occurred at different areas. Obtained electrical reliability and failure modes were analyzed by observing crack morphologies.

Service FMECA of a bucket wheel excavator

Surface mining systems (SMSs) are among the most significant 20th century achievements in mining industry, whose significance to miners is comparable to the invention of dynamite in the 19th century. However, problems of SMS risk assessment are very scarce in relevant literature. For this reason, this paper aims to establish a consistent risk quantification approach for bucket wheel excavators (BWEs), the backbones of these systems. Based on the original structural scheme of a BWE, the risk parameters assessing criteria stemming from multidecadal experience and the database of recorded standstills (in the considered case, one hour of SMS downtime generates indirect financial losses of ≈15000€), a study was conducted applying the Service FMECA technique to the BWE SRs2000 (one of the best-selling models from “Takraf”), with the following conclusions: (a) the material conveying subsystem is the highest contributor in the total number of mechanical and electrical failures, as well as in total downtime; (b) during the monitoring period, there were no extreme risk level failures. Besides, corrective actions for reducing risk levels of the most critical mechanical and electrical failure modes are given in the paper. The presented approach for risk quantification for a BWE can be successfully applied to other SMS subsystems, notably spreaders.

Experimental and Analytical Simulation Analyses on the Electrical Performance of Thermoelectric Generator Modules for Direct and Concentrated Quartz-Halogen Heat Harvesting

The scope of thermoelectric generators (TEGs), in improving the electric vehicle battery performance and glass/steel manufacturing industries, could achieve wider significance by harnessing the unused radiative heat and light conversion to electrical power. This paper experimentally investigates the electrical performance correlated to concentrated quartz-halogen, with acrylic Fresnel lens and heat-light harvesting, coupled with heat sink. This study also experimentally examined the influence of extreme temperature variance on the open circuit generated voltage of the Peltier electrical failure mode, compared to the standard performance parameters of the commercial TEG module. The research results presented provide expedient perception into the testing (open circuit voltage, short circuit current, and full load power) of a commercial heat-stove TEG to understand its performance limitations. The analytical simulation and mathematical model developed in MATLAB compared the electrical performance parameters and its dependencies. The analytical simulation shows that increasing the heat-sink temperature increases the efficiency of not more than 2% at the Δ T of 360 K, due to the limitation of the Z T ¯ of 0.43 at Δ T of 390 K. The maximum Z T ¯ of 0.7 for Bi2Te3, with an achievable efficiency of 4.5% at the Seebeck coefficient of 250 µV/K, was predicted. The design of three experimental setups and results presented demonstrate the functioning of TEG in stable and unstable temperature conditions, confirming the theoretical study and stipulating a quantity of the electrical output power in relation to extreme temperature conditions.

Electric Field Analysis of Press-Pack IGBTs

High voltage IGBT module is the ideal option for the VSC-HVDC power transmission application. At present, wire-bonded technology and press-pack technology are available packaging technologies for high voltage IGBT. The press-pack IGBTs have such advantages as low inductance, low thermal impedance and short circuit failure mode than the wire-bonded IGBT module, which especially suit for high voltage power transmission application by series connection. However, the electrical insulation failure modes of press-pack IGBTs are much less known with limited literature published. In this paper, we presented the electric field analysis of a 3D press-pack IGBT model under DC rating voltage test condition. The electric field distribution of the press-pack IGBT stack was solved as an electrostatic problem by employing the finite element method. The results revealed the potential electrical insulation failure modes of the press-pack IGBTs: corona discharge at the edge of silver plate, partial discharge at the micro gap between die and PEEK frame and creeping discharge at the surface of PEEK frame.

An efficient reliability testing method combined with thermal performance monitoring

Die attach delamination in power electronic devices is a common failure mode besides bond wire damage. This paper describes the chip and packaging level effects of a newly developed power cycling test on novel mid-power automotive MOSFETs. The introduced method was pilot tested with our new approach, using a recently developed test environment. The idea was to combine the existent guidelines of the most relevant semiconductor characterization and cycling standards while saving time and resources during testing. Thermal transient measurements during the actively mimicked temperature cycling reliability test were evaluated along with K-factor calibration to identify different failure modes. This approach allows distinguishing between electrical and thermal related structural failure modes. The major target was to test the reliability of a new thermal interface material which was used in the MOSFETs under test. We found that the new material was able to withstand the 150°C temperature amplitude beyond 100,000cycles without critical failures. The changes of the thermal performance of the complete assembly were tracked from the pre-stress state until a sample reached critical condition.

Electrical and thermal failure modes of 600 V p-gate GaN HEMTs

A study of electrical and thermal failure modes of 600V p-doped GaN HEMTs is presented, which focuses on the investigation of short-circuit limitations. The electrical failure mode seems to be an electrical field breakdown in the structure which is caused by excessive carrier concentration, rather than primary thermal generated. Accordingly, a thermal failure mode is observed, which features a distinctive behaviour and seems to be similar to schottky-gate HEMTs. Concerning the electrical failure mode, a specific p-gate HEMT short-circuit safe operating area (SCSOA) is presented as a novelty. However, a short-circuit capability of up to 520V can be achieved, regarding the design of the gate-drive circuit.

Current state of transformer FRA interpretation: On behalf of CIGRE WG A2.53

Measurement of the frequency response, from a few Hz to a few MHz, is now commonly used in the transformer industry for the condition assessment of transformer windings and has demonstrated its sensitivity for detecting various mechanical and electrical failure modes. The present generally applied practice for interpretation is visual comparison of frequency responses, either with a previous measurement on the same or an identical unit, or between the phases of a three-phase transformer. Examples of curve comparison for typical mechanical and electrical failure modes have previously been published in CIGRE and IEEE guides. Over the last 15 years, numerous technical papers have been published regarding the interpretation of the results in an aim to make it more objective and quantitative. In 2016, CIGRE initiated a new working group titled “Objective interpretation methodology for the condition assessment of transformer windings using Frequency Response Analysis (FRA)”. This paper, written on behalf of the new working group, reviews the basics of FRA interpretation and summarizes the state-of-the-art regarding the potential methods that can be applied to achieve a more objective and quantitative interpretation of the results.

Contact Chains for FinFET Technology Characterization

Electrical characterization remains a key element in technology development and manufacturing of integrated circuits. Contact chain is a well known part of the diagnostic set of test structures used across many generations of silicon processes. Implementation of such test structures becomes challenging in new technologies with 3-D devices, like FinFET. Contacts to active regions of such devices are inherently dependent on the architecture of epitaxial raised source and drain and for proper characterization require the presence of transistor gates, which set the environment for contacts. This paper describes a new type of test structure, so-called gated contact chains, developed for contact process characterization in FinFET technologies. Instead of simple chain of contacts, each structure contains a series of active devices with common gate electrode used to turn on the chain of transistors to enable measurement of chain resistance. To discriminate between chain failures caused by an open contact or by other mechanisms (e.g., bad transistor with very high threshold voltage) a series of measurement under various test conditions was performed and analysed. In order to overcome a limitation of the contact chain size and enable data collection from larger sample of contacts, we proposed to implement the gated chains in addressable arrays, increasing their density and failure rate observability. Finally, the paper presents the examples of electrical failure modes detected by those chains in FinFET process.

Mechanical Failure Mode Causes of In-Wheel Motors

The presented survey includes a comprehensive overview of mechanical failure mode causes for direct driven electric in-wheel motors. As electric vehicles evolve and develop, in-wheel motor driven vehicles gain acknowledgement, more and more papers are published in order to show individual design challenges and overcoming solutions for failure causes and effects. Obtainable literature is mainly concerned with integral electrical failure modes, neglecting structural causes and effects which in some cases interact. The presented paper inspects the most likely potential mechanical causes of failure modes for in-wheel motors and shows related paper’s results for comparison and reference. As several mechanical and electromagnetic layouts and construction topologies exist, only the most promising and generally used one has been studied within this work in order to emphasize sensible directions of further development. Failure mode and effect analysis (FMEA) has been made with severity rating which present mechanical failure potential for permanent magnet synchronous motors intended for in-wheel motor application.

Combined electronic and thermal breakdown Models for polyethylene and polymer laminates

A comprehensive DC dielectric breakdown model has been extended for polyethylene in which specific time and voltage regimes were identified for thermal and electrical failure modes. In addition to electron injection processes, space-charge formation and the associated electric field distribution are critical in determining the conditions for insulator failure. Space charge formation and distribution are governed by electron and hole injection from the electrode as well as charge mobility and trapping. Breakdown fields of 5MV/cm are predicted through a computational model for polyethylene films in the 5 to 200µm thickness range and there is weak dependence of breakdown field on thickness. The model is applied to predict the effect of interfaces for multilayer polymer structures that act as barriers.

Reliability research on micro- and nano-electromechanical systems: a review

Research on micro/nano-electro-mechanical system (MEMS/NEMS) reliability is of crucial importance, due to the fact that we are facing an era in which MEMS and emerging NEMS are expected to have a major impact on our lives. Over the last decade, significant efforts have gone into the reliability study of MEMS/NEMS. Failure roots in micro- and nano-scales can be addressed by mechanical, electrical, chemical, thermal factors, or combinations of them, which can occur during different manufacturing and post-manufacturing phases. This paper reviews and integrates the reliability issues of MEMS and NEMS in different phases of their life cycles including design, manufacturing, logistics, and operation. This paper surveys the common failure modes and mechanisms (i.e., wear, degradation, adhesion, stiction, deformation, packaging, contamination, and electrical failure modes), the reliability aspects of design and manufacturing, as well as reliability evaluation and testing techniques for MEMS/NEMS. An extensive collection of papers were selected and integrated to cover various studies in this area, in order to provide an intuition and insight for researchers who are interested in reliability research of MEMS/NEMS. Systematic literature search shows the lack of research in system-level and probabilistic reliability analysis for MEMS/NEMS.

Assessing the early degradation of photovoltaic modules performance in the Saharan region

In this study, the electrical performance degradation of photovoltaic modules (UDTS-50) functioning for a period of 11years in a region of the Sahara (URER-MS ADRAR) is analyzed. This paper is devoted to an experimental study of current–voltage characteristics of several PV modules exposed to the extreme weather conditions in desert area. The electrical performance degradation and failure modes are estimated from series of current–voltage characteristics performed in the field. Experimental results show that some PV modules degrade up to 12% compared to their initial state. The performance analysis of the others tested modules revealed some defects, such as cracked cells and physical material defects. The identification of the origin of degradation and failure modes and how they affect the photovoltaic modules is necessary to improve the reliability of photovoltaic installations.

하이브리드 굴삭기용 선회감속기의 가속수명시험에 관한 연구

하이브리드 굴삭기는 기존 굴삭기와 달리 선회구동계에 유압모터를 대신하여 선회전동기를 사용하고 있다. 하이브리드 굴삭기의 신뢰성을 평가하고 보증하기 위해서는 기계와 전기적인 고장모드가 조합되어 고려되어야 한다. 특히, 하이브리드 굴삭기용 선회감속기는 가혹한 실외환경에서 운용되므로 시작품에 대한 현장작동조건을 고려한 가속수명시험이 수행되어야 한다. 본 연구에서는 선회구동계 중선회감속기에 대한 가속수명시험 기법의 개발을 위하여 FMMA, FMAECA, FTA 및 QFD와 같은 정성적 신뢰성기법을 활용하였고, 개발된 가속조건에 의한 수명시험결과를 유분석 기법 등을 활용 분석하여 평가대상 시료가 목표 신뢰도를 만족함을 확인하였다.

Design of the Fault Diagnosis and Maintenance Support System of New Self-Propelled Artillery Electromechanical Equipment

As the research object based on a variety of models of self-propelled artillery electromechanical equipment, detailed analysis was carried out on the self-propelled guns electrical equipment failure mode by using the artificial intelligence diagnosis and data mining technology, and a comprehensive, universal and high stability fault diagnosis and maintenance support system for the new self-propelled artillery electromechanical equipment is developed, which realize offline testing, FBI test and quality assessment, a combination of fault diagnosis, maintenance decision-making and information management. Based on the system hardware platform, the fault diagnosis model and maintenance information management system are established, the corresponding fault diagnosis and maintenance support system are finally developed.By passing test, the system have strong comprehensive ,good versatility and the characteristics of high stability.

Reliability & Availability of Wind Turbine Electrical & Electronic Components

Recent analysis of European onshore wind turbine reliability data has shown that whilst wind turbine mechanical subassemblies tend to have relatively low failure rates but long downtimes, electrical and electronic subassemblies have relatively high failure rates and short downtimes. For onshore wind turbines the higher failure rates of electrical and electronic subassemblies can be managed by a maintenance regime that provides regular and frequent attendance to wind turbine sites. This regime will be costly or impossible to sustain in more remote onshore or offshore wind farm sites. This paper gathers data supporting the contention that electrical and electronic subassembly failure modes are a significant contributor to wind turbine unreliability, identifying some of their root causes, showing how they will play a more significant part in the availability of offshore wind turbines. The paper concludes by showing how more can be learnt to eliminate or mitigate some of these electrical and electronic subassembly failure modes.

Effect of CFRC layers on the electrical properties and failure mode of RC beamsstrengthened with CFRC composites

This paper designs an innovative reinforced concrete (RC) beam strengthened with carbonfiber reinforced concrete (CFRC) composites. Six groups of test beams, five with differentdegrees of strengthening, achieved by changing the location and the thickness of the CFRClayer, and one virgin RC beam, were tested in four-point bending over a span of 3000 mm.We investigate the effect of the CFRC layer on the flexural performance and theelectrical properties of the designed beams. The test results indicate that the CFRCstrengthened RC beam exhibits improved electrical properties as well as bettermechanical performance. Also, the location and the thickness of the CFRC layeraffect the initial electrical resistance and other electrical properties of the beam.Relationships between electrical resistance, loading, deflection and cracks show that theincrease in the electrical resistance can be used to monitor the extent of damage tothe designed beam. Based on this discovery, a new health monitoring techniquefor RC structures is produced by means of electrical resistance measurements.