Reliability Prediction for Offshore Renewable Energy: Data Driven Insights

2017 ◽  
Author(s):  
Fraser J. Ewing ◽  
Philipp R. Thies ◽  
Benson Waldron ◽  
Jonathan Shek ◽  
Michael Wilkinson
Keyword(s):  
Renewable Energy ◽  
Failure Rate ◽  
Reliability Assessment ◽  
Surrogate Data ◽  
Data Sources ◽  
Reliability Prediction ◽  
Failure Rates ◽  
Onshore Wind ◽  
Energy Devices ◽  
Frequency Converters

Accurately quantifying and assessing the reliability of Offshore Renewable Energy (ORE) devices is critical for the successful commercialisation of the industry. At present, due to the nascent stage of the industry and commercial sensitivities there is very little available reliability field data. This presents an issue: how can the reliability of ORE’s be accurately assessed and predicted with a lack of specific reliability data? ORE devices largely rely on the assessment of surrogate data sources for their reliability assessment. To date there are very few published studies that empirically assess the failure rates of offshore renewable energy devices [1]. The applicability of surrogate data sources to the ORE environment is critical and needs to be more thoroughly evaluated for a robust ORE device reliability assessment. This paper tests two commonly held assumptions used in the reliability assessment of ORE devices. Firstly, the constant failure rate assumption that underpins ORE component failure rate estimations is addressed. Secondly, a model that is often used to assess the reliability of onshore wind components, the Non-Homogeneous Poisson Power Law Process (PLP) model is empirically assessed and trend tested to determine its suitability for use in ORE reliability prediction. This paper suggests that pitch systems, generators and frequency converters cannot be considered to have constant failure rates when analysed via nonrepairable methods. Thus, when performing a reliability assessment of an ORE device using non-repairable surrogate data it cannot always be assumed that these components will exhibit random failures. Secondly, this paper suggests when using repairable system methods, the PLP model is not always accurate at describing the failure behaviour of onshore wind pitch systems, generators and frequency converters whether they are assessed as groups of turbines or individually. Thus, when performing a reliability assessment of an ORE device using repairable surrogate data both model choice and assumptions should be carefully considered.

A Method for Predicting Results of Humidity Tests

1986 ◽  
Vol 29 (6) ◽  
pp. 22-28
Author(s):  
Alan Harris
Keyword(s):  
Failure Rate ◽  
Exposure Time ◽  
Reliability Prediction ◽  
Prediction Methods ◽  
Failure Rates ◽  
Severity Factor ◽  
Base Level ◽  
Test Conditions ◽  
Total Failure ◽  
Entry Mechanism

The paper outlines a method for predicting the results of humidity tests applied to electronic equipments. It is based on a theory of vapor entry into parts to cause failure. Depending on the packaging, the entry mechanism and the test conditions, the rate of vapor entry can be calculated and a severity factor can be estimated for different test levels. If a base level is set at about 25°C (77°F) and 50% RH, a base failure rate can be derived for each part from the dormant or storage failure rates, which are well established. The expected failure rate under the test is derived from the base failure rate and the acceleration factor for each part in an equipment or unit to calculate a total failure rate. With the total failure rate and the test exposure time, the basic reliability equation can be used to calculate the probability of passing or failing the test. The method provides an estimate of the probability similar in principle and with an accuracy comparable to the reliability prediction methods of MIL-HDBKD-217. Examples of prediction and references are given.

Offshore Reliability Approach for Floating Renewable Energy Devices

2011 ◽  
Author(s):  
Lars Johanning ◽  
Philipp R. Thies ◽  
David Parish ◽  
George H. Smith
Keyword(s):  
Renewable Energy ◽  
Reliability Assessment ◽  
Test Rig ◽  
Sea Trial ◽  
Energy Devices ◽  
Marine Renewable Energy ◽  
Response Data ◽  
Research Institution ◽  
Research Activities ◽  
Component Test

This paper describes the test facilities developed within the Peninsular Research institution for Marine Renewable Energy (PRIMaRE) group and discusses the approach of the group to mitigate risk for marine renewable energy installations. The main consideration is given to the reliability assessment of components within mooring configurations and towards power umbilical for typical renewable energy sites. Load and response data from sea trial will be used to highlight the importance of these research activities, and a Dynamic Marine Component Test rig (DMaC) is introduced that allows four degree of freedom fatigue or destructive tests. Furthermore it is discussed how this facilities could also aid in the reliability assessment of wider offshore applications.

Failure Estimation of Offshore Renewable Energy Devices Based on Hierarchical Bayesian Approach

2019 ◽  
Author(s):  
Mohammad Mahdi Abaei ◽  
Nu Rhahida Arini ◽  
Philipp R. Thies ◽  
Johanning Lars
Keyword(s):  
Renewable Energy ◽  
Reliability Assessment ◽  
Tidal Energy ◽  
Bayesian Framework ◽  
Reliability Estimation ◽  
Observation Data ◽  
Hierarchical Bayesian ◽  
Energy Devices ◽  
Mcmc Sampling ◽  
Component Failures

Abstract Improving the reliability of marine renewable energy devices such as wave and tidal energy convertors is an important task, primarily to minimize the perceived risks and reduce the associated cost for operation and maintenance. Marine systems involve a wide range of uncertainties, due to the complexity of failure mechanism of the marine components, scarcity of data, human interactions and randomness of the sea environment. The fundamental element of a probabilistic risk analysis necessarily needs to rely on operational information and observation data to quantify the performance of the system. However, in reality it is difficult to ascertain observation of the precursor data according to the number of component failures that have occurred, mainly as a result of imprecision in the failure criterion, record keeping, or experimental and physical modelling of the process. Traditional reliability estimation approaches such as Fault Tree, Event Tree and Reliability Block Diagram analysis offer simplified, rarely realistic models of this complex reliability problem. The main reason is that they all rely on accurate prior information as a perquisite for performing reliability assessment. In this paper, a hierarchical Bayesian framework is developed for modelling marine renewable component failures encountered the uncertainty. The proposed approach is capable to incorporate the conditions, which lack reliable observation data (e.g. unknown/uncertain failure rate of a component). The hierarchical Bayesian framework provides a platform for the propagation of uncertainties through the reliability assessment of the system, via Markov Chain Monte Carlo (MCMC) sampling. The advantages of using MCMC sampling has proliferated Bayesian inference for conducting risk and reliability assessment of engineering system. It is able to use hyper-priors to represent prior parameters as a subjective observations for probability estimation of the failure events and enable an updating process for quantitative reasoning of interdependence between parameters. The developed framework will be an assistive tool for a better monitoring of the operation in terms of evaluating performance of marine renewable system under the risk of failure. The paper illustrates the approach using a tidal energy convertor as a case study for estimating components failure rates and representing the uncertainties of system reliability. The paper will be of interest to reliability practitioners and researchers, as well as tidal energy technology and project developers, seeking a more accurate reliability estimation framework.

scholarly journals Estimate the useful life for a heating, ventilation, and air conditioning system on a high-speed train using failure models

ACTA IMEKO ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 100
Author(s):  
Marcantonio Catelani ◽  
Lorenzo Ciani ◽  
Giulia Guidi ◽  
Gabriele Patrizi ◽  
Diego Galar
Keyword(s):  
Failure Rate ◽  
Air Conditioning ◽  
High Speed ◽  
Field Data ◽  
Block Diagram ◽  
Reliability Assessment ◽  
Fault Tree Analysis ◽  
Reliability Prediction ◽  
Rate Model ◽  
Mechanical Components

<p class="Abstract">Heating, ventilation, and air conditioning (HVAC) is a widely used system used to guarantee an acceptable level of occupancy comfort, to maintain good indoor air quality, and to minimize system costs and energy requirements. If failure data coming from company database are not available, then a reliability prediction based on failure rate model and handbook data must be carried out. Performing a reliability prediction provides an awareness of potential equipment degradation during the equipment life cycle. Otherwise, if field data regarding the component failures are available, then classical reliability assessment techniques such as Fault Tree Analysis and Reliability Block Diagram should be carried out. Reliability prediction of mechanical components is a challenging task that must be carefully assessed during the design of a system. For these reasons, this paper deals with the reliability assessment of an HVAC using both failure rate model for mechanical components and field data. The reliability obtained using the field data is compared to the one achieved using the failure rate models in order to assess a model which includes all the mechanical parts. The study highlights how it is fundamental to analyze the reliability of complex system integrating both field data and mathematical model.</p>

scholarly journals Reliability Assessment of Photoelectric Smoke Detector, Ionization Smoke Detector and a Fire Alarm Control Panel with Both Detectors AS Notification Device

2019 ◽  
Vol 9 (2) ◽  
pp. 1383-1390
Keyword(s):  
Weibull Distribution ◽  
Failure Rate ◽  
Reliability Assessment ◽  
Smoke Detector ◽  
Battery Life ◽  
Control Panel ◽  
Failure Rates ◽  
Electronic Components ◽  
Smoke Alarms ◽  
Fire Alarm

Notification device like smoke detectors are critical and important part of a Fire Alarm Control Panel (FACP). Popularly used smoke alarms in commercial establishments in India are photoelectric smoke alarms (PESD) and ionization smoke alarms (ISD). In this study reliability assessments of PESD with Integrated Circuit (IC) – MC145010 and ISD with IC – MC145017 have been carried out on the basis of reliabilities of their respective electronic components. The cases considered are: (I) Failure rates of all components are equal and constant over time (II) Failure rates of all components are equal and follow Weibull distribution and (III) Failure rates of all components are different. To determine failure rates of 9 volt battery of both detectors additional assumptions taken are, (a) battery life is 10 years with constant failure rate, (b) battery life follows Weibull distribution. In this paper the reliability and failure rate of two types of smoke alarms have been calculated based on failure rates of their electronic parts like resistors, capacitors, Integrated Circuits etc. These failure rates have been subsequently used for reliability assessment of a non-addressable FACP containing four PESDs and four ISDs as notification device. A comparison of failure rates was also performed on the basis of two quality factors of electronic components – military specific and lower than military specific. Mean Time To Failure (MTTF) of PESD and ISD have been calculated in all the cases. Subsequently, MTTF values obtained in case III were used to approximate failure rates for case I case II.

Electromigration and Electrochemical Reaction Mixed Failure Mechanism in Gold Interconnection System

1999 ◽  
Author(s):  
Hide Murayama ◽  
Makoto Yamazaki ◽  
Shigeru Nakajima
Keyword(s):  
Failure Mechanism ◽  
Failure Rate ◽  
Electrochemical Reaction ◽  
Dielectric Films ◽  
Failure Rates ◽  
Interlayer Dielectric ◽  
Bipolar Devices ◽  
Gold Metallization

Abstract Power bipolar devices with gold metallization experience high failure rates. The failures are characterized as shorts, detected during LSI testing at burn-in. Many of these shorted locations are the same for the failed devices. From a statistical lot analysis, it is found that the short failure rate is higher for devices with thinner interlayer dielectric films. Based upon these results, a new electromigration and electrochemical reaction mixed failure mechanism is proposed for the failure.

scholarly journals Erratic electric power challenges in Africa and the way forward via the adoption of human biogas resources

2021 ◽  
pp. 014459872110036
Author(s):  
Moses E Emetere ◽  
O Agubo ◽  
L Chikwendu
Keyword(s):  
Renewable Energy ◽  
Electric Power ◽  
Technological Innovations ◽  
Government Agencies ◽  
Electric Power Supply ◽  
Energy Devices ◽  
Gas Generators ◽  
Financial Base ◽  
Energy Companies ◽  
The Way

This paper examines a broad spectrum of challenges plaguing electric power supply in Africa. The challenges have lingered very long that policymakers, energy companies, and government agencies have shown docility in tackling the problem headlong. The increasing human population and technological innovations are evidence that the more the problem lingers, the more it becomes insurmountable. In this paper, it was proposed the lingering challenges can be solved using the standalone system of power generation. The renewable energy option and its adaptability were highlighted to guide standalone users on the way forward. The growing population in Africa can be advantageous in generating biogas from human feaces. It was discovered that renewable energy devices are quite expensive; hence, the biogas option for cooking and powering gas generators seem to be sustainable as its technology can be modified to suit the users' financial base. Therefore, it is projected that if the human excretal biogas can be adopted, Africa will soon overcome its energy crisis through the doggedness of its standalone users.

Outcomes of Inside-out Meniscal Repair in the Setting of Multiligament Reconstruction in the Knee

2017 ◽  
Vol 45 (9) ◽  
pp. 2098-2104 ◽  
Author(s):  
Jorge Chahla ◽  
Chase S. Dean ◽  
Lauren M. Matheny ◽  
Justin J. Mitchell ◽  
Mark E. Cinque ◽  
...  
Keyword(s):  
Failure Rate ◽  
Meniscal Repair ◽  
Postoperative Outcome ◽  
Control Group ◽  
Failure Rates ◽  
Significant Difference ◽  
Outcome Scores ◽  
Inside Out ◽  
Repair Group

Background: Limited evidence exists for meniscal repair outcomes in a multiligament reconstruction setting. Purpose/Hypothesis: The purpose of this study was to assess outcomes and failure rates of meniscal repair in patients who underwent multiligament reconstruction compared with patients who underwent multiligament reconstruction but lacked meniscal tears. The authors hypothesized that the outcomes of meniscal repair associated with concomitant multiligament reconstruction would significantly improve from preoperatively to postoperatively at a minimum of 2 years after the index surgery. Secondarily, they hypothesized that this cohort would demonstrate similar outcomes and failure rates compared with the cohort that did not have meniscal lesions at the time of multiligament reconstruction. Study Design: Cohort study; Level of evidence, 3. Methods: Inclusion criteria for the study included radiographically confirmed skeletally mature patients of at least 16 years of age who underwent multiligamentous reconstruction of the knee without previous ipsilateral osteotomy, intra-articular infections, or intra-articular fractures. Patients were included in the experimental group if they underwent inside-out meniscal suture repair with concurrent multiligament reconstruction. Those included in the control group (multiligament reconstruction without a meniscal tear) underwent multiligament reconstruction but did not undergo any type of meniscal surgery. Lysholm, Western Ontario and McMaster Universities Osteoarthritis Index, Short Form–12 physical component summary and mental component summary, Tegner activity scale, and patient satisfaction scores were recorded preoperatively and postoperatively. The failure of meniscal repair was defined as a retear of the meniscus that was confirmed arthroscopically. Results: There were 43 patients (16 female, 27 male) in the meniscal repair group and 62 patients (25 female, 37 male) in the control group. Follow-up was obtained in 93% of patients with a mean of 3.0 years (range, 2.0-4.7 years). There was a significant improvement between all preoperative and postoperative outcome scores ( P < .05) for both groups. The meniscal repair group had significantly lower preoperative Lysholm and Tegner scores ( P = .009 and P = .02, respectively). There were no significant differences between any other outcome scores preoperatively. The failure rate of the meniscal repair group was 2.7%, consisting of 1 symptomatic meniscal retear. There was no significant difference in any postoperative outcome score at a minimum 2-year follow-up between the 2 groups. Conclusion: Good to excellent patient-reported outcomes were reported for both groups with no significant differences in outcomes between the cohorts. Additionally, the failure rate for inside-out meniscal repair with concomitant multiligament reconstruction was low, regardless of meniscus laterality and tear characteristics. The use of multiple vertical mattress sutures and the biological augmentation resulting from intra-articular cruciate ligament reconstruction tunnel reaming may be partially responsible for the stability of the meniscal repair construct and thereby contribute to the overall improved outcomes and the low failure rate of meniscal repair, despite lower preoperative Lysholm and Tegner scores in the meniscal repair group.

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