Search

Objective. Safety on the railway transport and its uninterrupted operation depends considerably on the reliability of the work of the means of railway automation and communication. In this case, special role in ensuring the efficient and safe operation of railways belongs to the systems of interval control of the movement of trains, as well as automatic locomotive signaling in conjunction with the systems of monitoring the driver's vigilance and hitchhiking. Therefore, it is necessary to continuously investigate and perform a detailed analysis of the reliability of these systems' operations, in order to be able, based on the information received, to correct service techniques and improve operational work. Technique. To prevent halting and failures in the operation of automatic locomotive signaling devices, it was analyzed the statistics of failures of all devices of railway automatics, which can lead to disturbances in its work. It was identified the most responsible devices, whose control will greatly affect the system performance and increase the reliability of the work as a whole. Results. Analysis of statistical data showed that the main objects that led to violations of the automatic locomotive signaling system is the failure of decoders, amplifiers and locomotive filters, and the main reason causing the malfunction remains the wear of the equipment. Scientific novelty. The results of the work aimed at increasing the efficiency and reliability of the operation of the railway equipment are continuously implemented in the operational work, automating a large number of technological processes and increasing the probability of failure-free operation of the equipment. However, despite this, the analysis of the work of the railway equipment with the research for 2013-2017 has shown that the human factor, namely, the violation of the technology of production work, non-compliance with the requirements of technological cards and manuals, poor quality repair and verification of instruments in the repair and technological sites, remains significantly high the reliability of the operation of the railway equipment in general and in the systems of locomotive signaling in particular. Practical value. The analysis showed that the issue of improving both the systems themselves and the devices of railway automatics, as well as methods of their inspection, operation and maintenance, will increase the level of safety and reliability of transportations., Цель. Безопасность на железнодорожном транспорте и его бесперебойная работа значительно зависит от надежности работы средств железнодорожной автоматики и связи. При этом особая роль в обеспечении эффективной и безопасной работы железных дорог принадлежит системам интервального регулирования движения поездов, а также автоматической локомотивной сигнализации в сочетании с системами контроля бдительности машиниста и автостопом. Поэтому необходимо постоянно исследовать и делать детальный анализ надежности работы данных систем, чтобы иметь возможность на базе полученной информации корректировать методики обслуживания и совершенствовать эксплуатационную работу. Методика. Для предупреждения сбоев и отказов в работе устройств автоматической локомотивной сигнализации проанализирована статистика отказов всех устройств железнодорожной автоматики, которые могут привести к нарушениям в ее работе. Определены наиболее ответственные устройства, контроль которых значительно повлияет на работоспособность системы и повысит надежность работы в целом. Результаты. Анализ статистических данных показал, что основными объектами, которые привели к нарушениям действия системы автоматической локомотивной сигнализации, является неисправность дешифраторов, усилителей и локомотивных фильтров, а основной причиной, обуславливающей неисправности, остается изношенность аппаратуры. Научная новизна. Результаты разработок, которые направлены на повышение эффективности и надежности работы железнодорожных устройств, постоянно внедряются в эксплуатационную работу, автоматизируя большое количество технологических процессов и повышая вероятность безотказной работы аппаратуры. Однако, несмотря на это, анализ работы железнодорожных устройств за исследованные 2013-2017 годы показал, что человеческий фактор, а именно нарушение технологии производства работ, несоблюдение требований технологических карт и руководств по эксплуатации, некачественный ремонт и поверка приборов в РТД, остается существенно высоким в надежности работы железнодорожной аппаратуры в целом и в системах локомотивной сигнализации в частности. Практическая значимость. Проведенный анализ показал, что актуальным остается вопрос совершенствования как непосредственно самих систем и устройств железнодорожной автоматики, так и методов их проверки, эксплуатации и обслуживания, которые повысят уровень безопасности и надежности перевозок., Мета. Безпека на залізничному транспорті та його безперебійна робота значно залежить від надійності роботи засобів залізничної автоматики та зв’язку. При цьому особлива роль у забезпеченні безперервності перевізного процесу залізниць належить системам інтервального регулювання руху поїздів, а також автоматичній локомотивній сигналізації у поєднанні з системами контролю пильності машиніста та автостопом. Тому необхідно постійно досліджувати та робити детальний аналіз надійності роботи даних систем, щоб мати змогу на базі отриманої інформації корегувати методики обслуговування та вдосконалювати експлуатаційну роботу персоналу. Методика. Для попереджування збоїв та відмов у роботі пристроїв автоматичної локомотивної сигналізації проаналізовано статистику відмов всіх пристроїв залізничної автоматики, які можуть призвести до порушень у її роботі. Визначено найбільш відповідальні пристрої, контроль яких значно вплине на працездатність системи та підвищить надійність роботи в цілому. Результати. Аналіз статистичних даних показав що, основними об'єктами, що призводять до порушень дії системи автоматичної локомотивної сигналізації, є несправність дешифраторів, підсилювачів і локомотивних фільтрів, а основною причиною, що обумовлює несправності, залишається зношеність апаратури. Наукова новизна. Результати розробок, що направлені на підвищення ефективності та надійності роботи залізничних пристроїв, постійно впроваджуються в експлуатаційну роботу, автоматизуючи велику кількість технологічних процесів та підвищуючи ймовірність безвідмовної роботи апаратури. Проте, незважаючи на це, аналіз роботи залізничних пристроїв за дослідні 2013-2017 роки показав, що людський фактор, а саме порушення технології виконання робіт, недотримання вимог технологічних карт та керівництв з експлуатації, неякісний ремонт та перевірка приладів в ремонтно-технологічних ділянках, залишається суттєво високим в надійності роботи залізничної апаратури в цілому і в системах локомотивної сигналізації зокрема. Практична значимість. Проведений аналіз показав, що актуальним залишається питання вдосконалення як безпосередньо самих систем та пристроїв залізничної автоматики, так і методів їх перевірки, експлуатації та обслуговування, що підвищить рівень безпеки та надійності перевезень.

Analysing and predicting system performance and availability depends largely upon reliabilityand maintenance data. Attaining statistically credible data can require observations from several years of operations. Fortunately, this data collection process can be quickened if this datais shared within the community of organisations in the same working domain. The goal of this task is to develop an open reliability information system to provide a common platform for storing and sharing reliability information on components in the area of energymanagement. The work is accompanied by a prototyping activity that shall prove the conceptand create a foundation for gathering reliability information about selected key systems. Aspecial care is taken to ensure technical efficiency and meeting the legal and administrativeconstraints emerging from cooperation with industrial partners and regulatory bodies. The open reliability information systems focuses on industrial infrastructures in large scale facilities. The shared data will consist of system and subsystem reliability and maintenancestatistics, information on system structure and operation conditions as well as estimation ondata quality. The data will be used in quantitative reliability and availability assessments. Thestored data and intended use differ from traditional maintenance databases that are used forstoring individual equipment failure events. The development of an open reliability database started in the context of the Future Circular Collider - Cern (FCC) research project, where a platform for sharing reliability informationplayed a big role in the area of accelerator technology and this community did not have a platform yet. However, successful examples of this concept exist in oil, nuclear and wind powerindustries and this existing knowledge shall be used to benefit this project. This knowledgeincludes OREDA, EIReDA, SPARTA and WInD-Pool projects and ISO 6527, ISO 14224 andISO/TR 12489 standards.

Purpose. The safety of the transportation process in railway transport and its continuous operation to a large extent depend on the reliability of the means of railway automation and communication. In this case, special role in ensuring the efficient and safe operation of railways belongs to the systems of interval control of the train movement, as well as automatic locomotive signaling in conjunction with the systems of monitoring the driver's vigilance and automatic train stop. Therefore, the main purpose of the article is a detailed analysis of the operation reliability of these systems, in order to be able to correct service techniques and improve operational work, based on the information received. Methodology. To prevent halting and failures in the operation of automatic locomotive signaling devices, it was analyzed the failure statistics of all devices of railway automatics, which can lead to disturbances in its work. It was identified the most responsible devices, whose control will greatly affect the system performance and increase the reliability of the work as a whole. Findings. Analysis of statistical data showed that the main causes of malfunctions in the automatic locomotive signaling system are the failure of the decoder, locomotive filter and amplifier, and the main reason for the malfunction is equipment wear. Originality. The results of the work aimed at increasing the efficiency and reliability of the operation of the railway equipment are continuously implemented in the operational work, automating a large number of technological processes and improving the failure rate performance. However, ignoring this, the analysis of the operation of devices on the railways for the period 2013–2017 showed that a significant part of the reasons for the deterioration of the reliability of all systems of railway automation and separately considered locomotive alarm system accrue to the human factor, embodied in violations of the technology of work and non-compliance with the requirements of technological maps and manuals, as well as poor repair and inspection of devices in repair and technological areas. Practical value. The analysis showed that the issue of improving both the systems themselves and the devices of railway automatics, as well as the methods of their inspection, operation and maintenance, will increase the level of safety and reliability of transportations., Мета. Безпечність перевізного процесу на залізничному транспорті та його безупинна робота значною мірою залежать від надійності роботи засобів залізничної автоматики та зв’язку. Особлива роль у забезпеченні безперервності перевізного процесу залізниць належить системам інтервального регулювання руху поїздів, а також автоматичній локомотивній сигналізації у поєднанні із системами контролю пильності машиніста та автостопом. Тому основною метою нашої статті є детальний аналіз надійності роботи цих систем, щоб мати змогу на базі отриманої інформації корегувати методики обслуговування та вдосконалювати експлуатаційну роботу персоналу. Методика. Для попередження збоїв та відмов у роботі пристроїв автоматичної локомотивної сигналізації проаналізовано статистику відмов усіх пристроїв залізничної автоматики, які можуть призвести до порушень. Визначено найбільш відповідальні пристрої, контроль яких значно вплине на працездатність системи та підвищить надійність роботи в цілому. Результати. Аналіз статистичних даних показав, що основною причиною порушень у роботі системи автоматичної локомотивної сигналізації є вихід із ладу дешифратора, локомотивного фільтра та підсилювача, а основною причиною, що обумовлює несправності, залишається зношеність апаратури. Наукова новизна. Результати розробок, спрямованих на підвищення ефективності та надійності роботи залізничних пристроїв, постійно впроваджують в експлуатаційну практику, автоматизуючи велику кількість технологічних процесів та поліпшуючи показники напрацювання апаратури на відмову. Попри це аналіз роботи пристроїв на залізницях за період 2013–2021 років засвідчив, що на людський фактор, позначений порушеннями технології виконання робіт і недотриманням вимог технологічних карт і посібників з експлуатації, а також неякісним ремонтом і перевіркою приладів на ремонтно-технологічних дільницях, припадає значна частка причин погіршення показників надійності роботи всіх систем залізничної автоматики та розглянутої системи локомотивної сигналізації. Практична значимість. Проведений аналіз показав, що вдосконалення як безпосередньо самих систем і пристроїв залізничної автоматики, так і методів їх перевірки, експлуатації та обслуговування підвищить рівень безпеки та надійності перевезень.

In this study, the failures in Transformer Centers in Mersin Province Erdemli District have been investigated. The causes of the failures have been discussed. It is aimed to create a method for the reasons of possible failures of power transformer. The data have been collected by investigating the faults occurring at the Erdemli Substations. The failure statistics of the 200 power transformer failures that occurred between 2003 and 2019 in the Erdemli district of Mersin province have been examined. Examples of different power transformer failures have been given in fault analysis. The reasons of power transformer failures and the precautions to be taken have been explained.

In the financial year 2009/10, the Great Britain (GB) rail infrastructure manager, Network Rail, spent £32 million on the failures within switches and crossings. Approximately 53% of those failures occurred within the switch panel. In addition, two major incidents in GB in recent years have highlighted a lack of understanding of the loads and vibrations experienced by, and the consequent rates of deterioration of, switch panels. This paper describes work which has been undertaken to help improve understanding of in-service loads experienced by switch panels and their consequent deterioration rate. Field experimentation has been designed and installed on four sites around GB, with the same design of switch. The change in response to loading, and the rate of deterioration, of the switch panels at each site was monitored over time. The effect of the vehicles and the deterioration were analysed individually before a comparison between the four sites. The analysis from the strain gauge measurements showed that there was an increase in the variance and maximum strains generated on the stock rail with the switch closed compared to when the switch is open. Finite element analysis was used to validate variation recorded by the strain gauges under similar loads.

This paper presents a simplified probabilistic model for thermally activated propagation of a nanocrack. In the continuum limit, the probabilistic motion of the nanocrack tip is mathematically described by the Fokker-Planck equation. In the model, the drift velocity is explicitly related to the energy release rate at the crack tip through the transition rate theory. The model is applied to analyze the propagation of an edge crack in a nanoscale element. The element is considered to reach failure when the nanocrack propagates to a critical length. The solution of the Fokker-Planck equation indicates that both the strength and lifetime distributions of the nanoscale element exhibit a power-law tail behavior but with different exponents. Meanwhile, the model also yields a mean stress-life curve of the nanoscale element. When the applied stress is sufficiently large, the mean stress-life curve resembles the Basquin law for fatigue failure. Based on a recently developed finite weakest-link model as well as level excursion analysis of the failure statistics of quasibrittle structures, it is argued that the simulated power-law tail of strength distribution of the nanoscale element has important implications for the tail behavior of the strength distribution of macroscopic structures. It provides a physical justification for the two-parameter Weibull distribution for strength statistics of large-scale quasibrittle structures, В статье предложена упрощенная вероятностная модель термоактивированного распространения нанотрещины. В континуальном пределе вероятностное движение вершины нанотрещины математически описывается уравнением Фоккера-Планка. В рамках модели скорость роста явным образом связана со скоростью высвобождения энергии в вершине трещины с использованием теории вероятности переходов. Рассмотрено распространение краевой трещины в наноразмерном элементе. При достижении критической длины нанотрещины происходит разрушение элемента. Решение уравнения Фоккера-Планка показывает, что распределения прочности и времени жизни наноразмерного элемента имеют степенные хвосты с различными показателями степени. Модель также позволяет получить зависимость среднего времени жизни наноразмерного элемента от уровня напряжений. В случае достаточно больших значений напряжений кривая зависимости среднего времени жизни наноразмерного элемента от напряжения соответствует соотношению Баскина для усталостного разрушения. На основе недавно разработанной модели слабейшего звена, а также анализа отклонений по уровням, используемых в статистике разрушения квазихрупких структур, показано, что степенной хвост распределения прочности наноразмерного элемента имеет большое значение для описания хвоста распределения прочности макроскопических структур. С его помощью можно получить физическое обоснование двухпараметрического распределения Вейбулла для описания статистики прочности большеразмерных квазихрупких структур.

The diversity of components in electricity distribution grids makes it impossible, or at least very expensive, to deploy monitoring and fault diagnostics to every individual element. Therefore, power distribution companies are looking for cheap and reliable approaches that can help them to estimate the condition of their assets and to predict the when and where the faults may occur. In this paper we propose a simplified representation of failure patterns within historical faults database, which facilitates visualization of association rules using Bayesian Networks. Our approach is based on exploring the failure history and detecting correlations between different features available in those records. We show that a small subset of the most interesting rules is enough to obtain a good and sufficiently accurate approximation of the original dataset. A Bayesian Network created from those rules can serve as an easy to understand visualization of the most relevant failure patterns. In addition, by varying the threshold values of support and confidence that we consider interesting, we are able to control the tradeoff between accuracy of the model and its complexity in an intuitive way. © 2016 IEEE

Offshore wind energy use is commonly suggested to play an important role in future electricity supply. However, long-term experience with thousands of onshore wind turbines explicitly hint on possible barriers for a safe, efficient, economic and user friendly supply relying on offshore wind energy. A national German programme shall on the one hand support the wind energy sector improving technology and O&M procedures towards higher reliability and availability, and on the other hand monitor the development in terms of techniques, electricity yields and cost. In the following, this scientific monitoring programme, the ‘Offshore∼WMEP’, is presented. The actual challenge of this programme is to convince numerous players with diverse points of interest to collaborate in gathering data and providing it for a jointly utilized database.

Monte Carlo simulations and probabilistic modeling are employed to understand the strength distribution of a planar bundle of local load-sharing fibers. The fibers are distributed randomly within a unit square according to a Poisson process, and the fiber strengths are Weibull distributed with exponent ?. Monte Carlo failure simulations of bundles comprised of up to 105 fibers suggests that the bundle strength distribution obeys weakest-link scaling for all ?. Also, a probabilistic model of the weakest-link event is proposed. This model introduces a failure event at a size scale between that of the fiber and that of the bundle, whose failure statistics follows that of equal load-sharing bundles. The weakest-link event is modelled as the growth of a tight cluster of these equal load-sharing bundles. The size of the equal load-sharing bundles increases with decreasing ?. The simulated bundle strength distributions and those predicted by the model are compared, and excellent agreement is obtained. � 2015 American Physical Society.

To evaluate the reliability of power systems, good estimates of the failure rates of the included components are needed. Better predictions can be performed if relevant factors that affect the failure rates are used, and an increasing number of models that include different types of factors have been presented recently. This paper proposes a categorization of failure rate factors into seven categories, based on the type of information for the factors. The categorization can be used to map future studies in the context of similar work. Furthermore, the paper presents a review of a number of publications that uses different factors to model the failure rate of different power system components. The failure rate factors used in the reviewed publications are categorized into the proposed seven categories and a comprehensive summary table is included. The used models and methods to estimate the failure rate in the reviewed publications are also noted in the summary table. This work was sponsored by SweGRIDS.QC 20141030 Reliability decision support based on existing data

Offshore wind energy use is commonly suggested to play an important role in future electricity supply. However, long-term experience with thousands of onshore wind turbines explicitly hint on possible barriers for a safe, efficient, economic and user friendly supply relying on offshore wind energy. A national German programme shall on the one hand support the wind energy sector improving technology and O&M procedures towards higher reliability and availability, and on the other hand monitor the development in terms of techniques, electricity yields and cost. In the following, this scientific monitoring programme, the 'OffshoreWMEP', is presented. The actual challenge of this programme is to convince numerous players with diverse points of interest to collaborate in gathering data and providing it for a jointly utilized database.

The wind turbine statistics in Finland comprise data on monthly production and downtime from grid connected turbines. Production statistics have been compiled since 1992 and failure statistics since 1996. This analysis examines the failure statistics from 72 wind turbines between the years 1996-2008 and presents the disturbance time of different components as a function of the life time of turbines. The result is an estimate for the downtime of each component and can be used when developing systematic methodologies for preventive maintenance. Wind technology has developed rapidly during this period of time which has also had an effect on the type of failures occurring in wind turbines and the reasons for downtime.

The wind turbine statistics in Finland comprise data on monthly production and downtime from grid connected turbines. Production statistics have been compiled since 1992 and failure statistics since 1996. This analysis examines the failure statistics from 72 wind turbines between the years 1996-2008 and presents the disturbance time of different components as a function of the life time of turbines. The result is an estimate for the downtime of each component and can be used when developing systematic methodologies for preventive maintenance. Wind technology has developed rapidly during this period of time which has also had an effect on the type of failures occurring in wind turbines and the reasons for downtime.

CIGRÉ WG A3.06 is undertaking a survey of reliability and failures of high voltage equipment in service. The time period covered by the survey is 2004 - 2007, and the equipment types under consideration are circuit breakers, disconnectors/earthing switches, instrument transformers and gas insulated substations. The information collected so far has been examined with the purpose of assessing the effect of age, or more precisely: the year of manufacture, on the failure characteristics. It appears that single pressure SF6 circuit breakers manufactured after 1994 shows only a slightly lower major failure rate than older ones. Thus, puffer breakers of the first generation appear not to have reached the end of their service life yet. The major failure rates for disconnector and earthing switches are strongly correlated with age. Equipment more that 30 years old have failure rates that are around five to ten times higher than recently installed equipment. Instrument transformers failure rates generally show little correlation with year of installation. However, one exception exists ; old capacitive voltage transformers have a higher failure rate. Gas insulated substations manufactured after 1994 have substantially lower major failure rates than those manufactured earlier. Quantitative results and more detailed assessments will be available after the survey has been completed and all the collected information has been analysed.