scholarly journals Reliability and Economic Efficiency Analysis of 4-Leg Inverter Compared with 3-Leg Inverters

Electronics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 87
Author(s):  
Yun-gi Kwak ◽  
Dae-ho Heo ◽  
Sun-Pil Kim ◽  
Sung-Geun Song ◽  
Sung-Jun Park ◽  
...  
Keyword(s):  
Failure Rate ◽  
Cost Model ◽  
Fault Tree Analysis ◽  
Mean Time Between Failures ◽  
Reliability Improvement ◽  
Time Between Failures ◽  
Unbalanced Load ◽  
Circuit Components ◽  
The Cost ◽  
Mean Time

The 4-leg inverter can adjust the load current or output voltage even under unbalanced load conditions, but it is known that the additional switch arm to the 3-leg inverter can increase the overall cost and the failure rate. This paper aims to analyze the failure rate and mean time between failures (MTBF) of 3-leg inverters and 4-leg inverters using part count failure analysis (PCA) and fault-tree analysis (FTA), and to compare the price of the inverters. The FTA can analyze the failure rate, including the type, number and connection status of the circuit components, and moreover the redundancy effect of the 4-leg inverter. For more accurate failure-rate prediction, the failure rate and MTBF of the 4-leg inverter according to the lifecycle of the controller are analyzed. Finally, by comparing the price of 3-leg inverters and 4-leg inverters using the cost model of major parts, the degree of reliability improvement against price increase is quantitatively analyzed.

scholarly journals Emphasis on Maintenance as Traffic Increasing Every Years -Ports

2020 ◽  
Vol 6 (5) ◽  
pp. 18-20
Keyword(s):  
Early Stage ◽  
Working Hours ◽  
Site Conditions ◽  
Operational Effectiveness ◽  
Mean Time Between Failures ◽  
Time Between Failures ◽  
Useful Life ◽  
Maintenance Schedules ◽  
The Cost ◽  
Mean Time

Maintenance plays a very pivotal role in the availability of the equipment’s, by eliminating of failure defects, forestall rapid wear of components, enhance performance level, reduce idle hours due to component malfunctioning, reduces the cost factor by identifying the fatigue in the early stage, by the early stage of detection the wear out can be drastically reduced and maximising the operational efficiency and prevent break down during operational working hours. The proper maintenance schedules yields minimisation of downtime by which the availability of the system improves and extends the useful life of the equipment and safety of the personnel working in the site conditions be secured optimistically. As the loose cargo and container shipments increasing in every years progressively the emphasis in the availability and probability of restoration of a failed equipment to operational effectiveness within a specified period of time, mean time to repair, mean time between failures parameters will certainly increases the customer satisfaction.

scholarly journals Retrofitting in Fabric Finishing Machine - Sanforizadeira

2021 ◽  
Vol 4 (2) ◽  
pp. 19-30
Author(s):  
Madson do Nascimento Araújo ◽  
Josias Guimarães Batista ◽  
André Pimentel Moreira ◽  
Danielle Alves Barbosa ◽  
Linconl Lobo Da Silva
Keyword(s):  
Failure Rate ◽  
Industrial Sector ◽  
Automation System ◽  
Mean Time Between Failures ◽  
Time Between Failures ◽  
Before And After ◽  
Long Time ◽  
Electronic Parts ◽  
Mean Time ◽  
Fabric Finishing

With the advancement of technology in all fields, mainly in the industrial sector, which is manifested in more modern and self-contained equipment. Many equipment in the industry are obsolete with the electrical and electronic parts, but the mechanical parts are in perfect condition and can often be used for a long time. This paper demonstrates the retrofitting of a fabric finishing machine (Sanforizadeira) in the textile process thet was obsolete. In these conditions, it became necessary to retrofit the automation system. Through the study of the machine and the process, involving the fields of production and mechanical maintenance, the critical points and the improvements that should be implemented were found, thus raising the materials needed to carry out the work. The automation system was modernized, the control panels were replaced and improvements were implemented. The final result was achieved through the objectives outlined in this work, guaranteeing the company a system with considerable improvements, with a reduction in the number of stops and time spent for maintenance. The results were demonstrated by the graphs of the maintenance indicators. Comparing the before and after retrofitting, the following indicators were analyzed for six months: Failure rate, with an average reduction of 50\% in the failure rate per hour; Mean time between failures, showed an average increase of 140 hours in the prediction of the next failures; Average time to repair, presented an average reduction of thirteen minutes in the resolution of the failures; Availability, there was a 16\% increase in the availability of the machine, leaving the indicator above 90\% where the ideal is 100\%. Finally, the total cost of the project represented only 9.5\% of the total value of a new machine, being also considered a positive result for the work.

Reliability Characteristics of a Safety Instrumented System via Markov Analysis

2004 ◽  
Author(s):  
Alejandro Di´az-Herna´dez ◽  
Mari´a Eloi´sa Pe´rez Medina
Keyword(s):  
Fault Tree Analysis ◽  
Markov Analysis ◽  
Mean Time Between Failures ◽  
Common Cause Failure ◽  
Time Between Failures ◽  
Reliability Characteristics ◽  
Hazard And Risk ◽  
Quantitative Results ◽  
Fail Safe ◽  
Mean Time

The Markov technique for determining the Reliability Characteristics (Probability of Failure on Demand, availability, Mean time to repair and Mean time between failures) of the Safety Instrumented System (SIS) on Offshore Metering and Custody Transfer Facility in Campeche Bay Mexico is presented in this work. Two important factors were considered based on the ISA TR84.0.02, Part 4: a) Common Cause Failure and b) the diagnostics capabilities were taking into account. The Markov technique methodology employed in order to assess and determine the Reliability characteristics of SIS was compared with Fault Tree Analysis previously analyzed, Part 3 of ISA TR84.0.02; for which the hazard and risk analysis mandated a SIL 2 for the SIS with two sets of sensors where each individual sensor can shut down the operation of the facility. Aspects like voting, redundancy or diversity bring about a full Markov model of a SIS, but it usually consists of intermediates states not significant for the assessment of the reliability characteristics. The quantitative results will mostly depend on the direct transitions to the fail-safe and fail-dangerous states. As a result, in most cases it was not necessary to present a fully developed model.

Review of Technological Advancements and HSE-Based Safety Model for Deep-Water Human Occupied Vehicles

2014 ◽  
Vol 48 (3) ◽  
pp. 25-42 ◽  
Author(s):  
Narayanaswamy Vedachalam ◽  
Gidugu Ananada Ramadass ◽  
Malayath Aravindakshan Atmanand
Keyword(s):  
Deep Water ◽  
Capital Expenditure ◽  
Mean Time Between Failures ◽  
Safety Integrity Level ◽  
Geological Surveys ◽  
Time Between Failures ◽  
High Resolution Bathymetry ◽  
Safety Systems ◽  
Mean Time ◽  
Safety And Environment

AbstractThis paper reviews the latest advancements in subsea technologies associated with the safety of deep-water human occupied vehicles. Human occupied submersible operations are required for deep-water activities, such as high-resolution bathymetry, biological and geological surveys, search activities, salvage operations, and engineering support for underwater operations. As this involves direct human presence, the system has to be extremely safe and reliable. Based on applicable IEC 61508 Standards for health, safety, and environment (HSE), the safety integrity level requirements for the submersible safety systems are estimated. Safety analyses are done on 10 critical submersible safety systems with the assumption that the submersible is utilized for 10 deep-water missions per year. The results of the analyses are compared with the estimated target HSE requirements, and it is found that, with the present technological maturity and safety-centered design, it is possible to meet the required safety integrity levels. By proper maintenance, it is possible to keep the mean time between failures to more than 9 years. The results presented shall serve as a model for designers to arrive at the required trade-off between the capital expenditure, operating expenditure, and required safety levels.

scholarly journals A Statistical State Analysis of a Marine Gas Turbine

Actuators ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 54 ◽  
Author(s):  
Suzana Lampreia ◽  
Valter Vairinhos ◽  
Victor Lobo ◽  
José Requeijo
Keyword(s):  
Gas Turbine ◽  
Point Of View ◽  
Operating Conditions ◽  
Environmental Data ◽  
Statistical Point ◽  
Mean Time Between Failures ◽  
Time Between Failures ◽  
Intervention Plan ◽  
Mean Time

This paper describes the analysis, from a statistical point of view, of a maritime gas turbine, under various operating conditions, so as to determine its state. The data used concerns several functioning parameters of the turbines, such as temperatures and vibrations, environmental data, such as surrounding temperature, and past failures or quasi-failures of the equipment. The determination of the Mean Time Between Failures (MTBF) gives a rough estimate of the state of the turbine, but in this paper we show that it can be greatly improved with graphical and statistical analysis of data measured during operation. We apply the Laplace Test and calculate the gas turbine reliability using that data, to define the gas turbine failure tendency. Using these techniques, we can have a better estimate of the turbine’s state, and design a preventive observation, inspection and intervention plan.

Comparison of the Mean Time Between Failures for Two Systems Under Short Tests

2009 ◽  
Vol 58 (4) ◽  
pp. 589-596 ◽  
Author(s):  
Y.H. Michlin ◽  
G.Y. Grabarnik ◽  
E. Leshchenko
Keyword(s):  
Mean Time Between Failures ◽  
Time Between Failures ◽  
Two Systems ◽  
The Mean ◽  
Mean Time

A warranty based bilateral multi-issue negotiation approach

2015 ◽  
Vol 22 (7) ◽  
pp. 1247-1280 ◽  
Author(s):  
Prashant M. Ambad ◽  
Makarand S. Kulkarni
Keyword(s):  
Real Life ◽  
Spare Parts ◽  
Negotiation Process ◽  
Design Stage ◽  
Automated Negotiation ◽  
Content Type ◽  
Mean Time Between Failures ◽  
Time Between Failures ◽  
Target Values ◽  
Mean Time

Purpose – The purpose of this paper is to propose a warranty-based bilateral automated multi-issue negotiation approach. Design/methodology/approach – A methodology for bilateral automated negotiation process is developed considering the targets such as warranty attractiveness, warranty cost, mean time between failures, spare parts cost to the end user over the useful life of the life. The negotiation methodology is explained using different cases of negotiation. The optimization for each negotiation step is carried out using genetic algorithm with elitism strategy. Findings – The result after optimization indicates that the desired target values are achieved and manufacturer obtained desired profit margin. Practical implications – Application of automated negotiation model is illustrated using a real life case of an automobile engine manufacturer. The proposed approach helps the manufacturer of any product to develop a methodology for carrying out the negotiation process. The approach also results into taking warranty-related decisions at the design stage. Originality/value – This paper contributes in proposing a generalized methodology for warranty-based negotiation in which the negotiation is carried out between the manufacturer and the customer.

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