Simulation and calculation of reliability performance and maintenance costs

2007 ◽  
Author(s):  
P.-E. Hagmark ◽  
S. Virtanen
Keyword(s):  
Maintenance Costs ◽  
Reliability Performance

scholarly journals Assessing Factors Impacting on Reliability of Wind Turbines by Use of Survival Analysis – A Case Study

2018 ◽  
Author(s):  
Samet Ozturk ◽  
Vasilis Fthenakis ◽  
Stefan Faulstich
Keyword(s):  
Survival Analysis ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Direct Drive ◽  
Maintenance Costs ◽  
Electrical Systems ◽  
History Of ◽  
Risk Rate ◽  
Reliability Performance

Failure of wind turbines is a multi-faceted problem and its monetary impact is often unpredicted. In this study, we present a novel application of survival analysis on wind turbine reliability performance that includes accounting of previous failures and history of scheduled maintenance. We investigate the operational, climatic and geographical factors which affect wind turbine failures and model the risk rate of wind turbine failures based on data from 109 turbines in Germany operating during a period of 19 years.  Our analysis showed that adequately scheduled maintenance can increase the survivorship of wind turbine systems and electric subsystems up to 2.8 and 3.8 times, respectively compared to the ones without scheduled maintenance. Geared-drive wind turbines and their electrical systems were observed to have 1.2- and 1.4-times higher survivorship, respectively, compared to direct-drive turbines and their electrical systems. It is also found that survivorship of frequently-failed wind turbine components, such as switches, is worse in geared-drive than in direct-drive wind turbines. We show that survival analysis is a useful tool for guiding the reduction of operating and maintenance costs of wind turbines.

2016 Planting and Annual Cultural Maintenance Costs for Reset-Replacement Trees in a Florida Citrus Grove

EDIS ◽  
2016 ◽  
Vol 2016 (7) ◽  
Author(s):  
Marina Burani Arouca ◽  
Stephen Hubbard Futch ◽  
Ariel Singerman
Keyword(s):  
Citrus Grove ◽  
Maintenance Costs ◽  
Cultural Maintenance ◽  
Florida Citrus ◽  
Citrus Trees

We provide estimates for the costs of planting and maintaining reset citrus trees in Florida in the era of HLB, The estimates are useful as a benchmark but also to inform industry stakeholders and policymakers regarding the costs growers have to incur in when planting new trees.

Saskatchewan Highways and Transportation Reduced Tire Pressure Initiative

1997 ◽  
Vol 1589 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Thomas L. Davies ◽  
Tami F. Wall ◽  
Allan Carpentier
Keyword(s):  
High Speed ◽  
Membrane Surface ◽  
Vehicle Stability ◽  
Road Maintenance ◽  
Long Term Effects ◽  
Tire Pressure ◽  
Reduced Pressure ◽  
Maintenance Costs ◽  
Short And Long Term

After examination of the research carried out by other agencies, Saskatchewan Highways and Transportation (SHT) embarked on an initiative to adapt low tire pressure technologies to the province's needs and environment. The focus of the initiative was to explore several technical questions from SHT's perspective: (a) Can low tire pressures be used to increase truck weights from secondary to primary without increasing road maintenance costs on thin membrane surface roads? (b) What are the short- and long-term effects of tire heating under high-speed/high-deflection constant reduced pressure (CRP) operations in a Saskatchewan environment? (c) What effects do lower tire pressures have on vehicle stability at highway speeds? To date, significant opportunities have been noted on local hauls (less than 30 min loaded at highway speeds) for CRP operation and long primary highway hauls that begin or end in relatively short secondary highway sections that limit vehicle weight allowed for the whole trip for central tire inflation technology. The background and environment for the initiative and the investigations and demonstrations envisioned and undertaken are briefly outlined.

Automated system for work preparation of parts production by sheet stamping

2020 ◽  
pp. 108-114
Author(s):  
L.R. Kashapova ◽  
D.L. Pankratov ◽  
V.G. Shibakov
Keyword(s):  
Deformation Process ◽  
Automated System ◽  
Tool Performance ◽  
Sheet Stamping ◽  
Mechanical And Physical Properties ◽  
Preparation Stage ◽  
Process Reliability ◽  
Recurrent Defects ◽  
Automated Process ◽  
Reliability Performance

The procedure of automated process reliability evaluation is developed in order to prevent recurrent defects in parts manufactured by die stamping. The procedure is based on the analysis of such factors as part design, material, its mechanical and physical properties; equipment parameters, tool performance, etc. The list of reliability factors may vary according to type of operation as deformation process is different for each group of operations. The adjustment of stamping process reliability performance prevents any defects emerging during production of critical parts as early as the work preparation stage.

Research Concerning the Identification of Some Parameters of a Sucker Rod Pumping Unit

2017 ◽  
Vol 68 (10) ◽  
pp. 2289-2292
Author(s):  
Dorin Badoiu ◽  
Georgeta Toma
Keyword(s):  
Computer Program ◽  
Essential Role ◽  
Automated Systems ◽  
Maintenance Costs ◽  
Motor Torque ◽  
Unit Process ◽  
Sucker Rod ◽  
Pumping Unit

One of the solutions to reduce the production and maintenance costs of the sucker rod pumping installations is to develop automated systems for regulating and controlling their operations. The development of these automated systems requires an attentive modeling of the dynamics of the mechanism of the pumping unit, process in which the identification of the values of the parameters involved in the calculations plays an essential role. The paper presents the manner of determining the values of some parameters of the mechanism of a C-320D-256-100 pumping unit starting from the variation on a cinematic cycle of the motor torque at the crank shaft. Simulations were performed with a computer program developed by the authors, and the experimental records were processed with the program Total Well Management.

scholarly journals Improving the Strategy of Maintaining Offshore Wind Turbines through Petri Net Modelling

2021 ◽  
Vol 11 (2) ◽  
pp. 574
Author(s):  
Rundong Yan ◽  
Sarah Dunnett
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Petri Net ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Maintenance Costs ◽  
Offshore Wind Turbines ◽  
Major Repair ◽  
Wind Turbine System ◽  
Periodic Maintenance

In order to improve the operation and maintenance (O&M) of offshore wind turbines, a new Petri net (PN)-based offshore wind turbine maintenance model is developed in this paper to simulate the O&M activities in an offshore wind farm. With the aid of the PN model developed, three new potential wind turbine maintenance strategies are studied. They are (1) carrying out periodic maintenance of the wind turbine components at different frequencies according to their specific reliability features; (2) conducting a full inspection of the entire wind turbine system following a major repair; and (3) equipping the wind turbine with a condition monitoring system (CMS) that has powerful fault detection capability. From the research results, it is found that periodic maintenance is essential, but in order to ensure that the turbine is operated economically, this maintenance needs to be carried out at an optimal frequency. Conducting a full inspection of the entire wind turbine system following a major repair enables efficient utilisation of the maintenance resources. If periodic maintenance is performed infrequently, this measure leads to less unexpected shutdowns, lower downtime, and lower maintenance costs. It has been shown that to install the wind turbine with a CMS is helpful to relieve the burden of periodic maintenance. Moreover, the higher the quality of the CMS, the more the downtime and maintenance costs can be reduced. However, the cost of the CMS needs to be considered, as a high cost may make the operation of the offshore wind turbine uneconomical.

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