scholarly journals Estimation of Parasitic Resistance of Electrolytic Capacitor and Filter Inductor and Prediction of Input Filter Induced Oscillations in a Switch-Mode Magnet Power Supply

2016 ◽  
Vol 2016 ◽  
pp. 1-9
Author(s):  
Rajul Lal Gour ◽  
Mangesh Borage ◽  
Alok Singh ◽  
Sunil Tiwari
Keyword(s):  
Closed Loop ◽  
Electrolytic Capacitor ◽  
Design Stage ◽  
Equivalent Series Resistance ◽  
Parasitic Resistance ◽  
Input Filter ◽  
Switch Mode ◽  
Actual Design ◽  
Converter Design ◽  
The Cost

In switch-mode power converters with large ratings, it is important to be able to predict the parasitic resistances associated with circuit elements such as electrolytic capacitor and filter inductor in the initial converter design stage itself to avoid the cost and time associated with actual design, prototype fabrication, and testing of these components. Knowing the values of parasitic elements is also important as they decide the possibility of closed-loop instability, besides affecting the other circuit parameters. In this paper, a way to estimate the equivalent series resistance of electrolytic capacitor and the winding resistance of filter inductor is proposed leading to their closed form expressions in terms of system parameters. Using these, procedure to predict the closed-loop instability induced due to the input filter is exemplified with illustrative calculations.

scholarly journals A METHODOLOGY TO SUPPORT COMPANIES IN THE FIRST STEPS TOWARDS DE-MANUFACTURING

2021 ◽  
Vol 1 ◽  
pp. 131-140
Author(s):  
Federica Cappelletti ◽  
Marta Rossi ◽  
Michele Germani ◽  
Mohammad Shadman Hanif
Keyword(s):  
Environmental Impact ◽  
End Of Life ◽  
Design Stage ◽  
Life Strategies ◽  
Disassembly Sequence ◽  
The Status ◽  
The Cost ◽  
Technical Solutions ◽  
First Time ◽  
Complex Activities

AbstractDe-manufacturing and re-manufacturing are fundamental technical solutions to efficiently recover value from post-use products. Disassembly in one of the most complex activities in de-manufacturing because i) the more manual it is the higher is its cost, ii) disassembly times are variable due to uncertainty of conditions of products reaching their EoL, and iii) because it is necessary to know which components to disassemble to balance the cost of disassembly. The paper proposes a methodology that finds ways of applications: it can be applied at the design stage to detect space for product design improvements, and it also represents a baseline from organizations approaching de-manufacturing for the first time. The methodology consists of four main steps, in which firstly targets components are identified, according to their environmental impact; secondly their disassembly sequence is qualitatively evaluated, and successively it is quantitatively determined via disassembly times, predicting also the status of the component at their End of Life. The aim of the methodology is reached at the fourth phase when alternative, eco-friendlier End of Life strategies are proposed, verified, and chosen.

scholarly journals A Constrained Markovian Diffusion Model for Controlling the Pollution Accumulation

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1466
Author(s):  
Beatris Adriana Escobedo-Trujillo ◽  
José Daniel López-Barrientos ◽  
Javier Garrido-Meléndez
Keyword(s):  
Dynamic Programming ◽  
Dirichlet Problem ◽  
Stochastic Control ◽  
Finite Time ◽  
Time Horizon ◽  
Closed Loop ◽  
Programming Techniques ◽  
Pollution Accumulation ◽  
Finite Time Horizon ◽  
The Cost

This work presents a study of a finite-time horizon stochastic control problem with restrictions on both the reward and the cost functions. To this end, it uses standard dynamic programming techniques, and an extension of the classic Lagrange multipliers approach. The coefficients considered here are supposed to be unbounded, and the obtained strategies are of non-stationary closed-loop type. The driving thread of the paper is a sequence of examples on a pollution accumulation model, which is used for the purpose of showing three algorithms for the purpose of replicating the results. There, the reader can find a result on the interchangeability of limits in a Dirichlet problem.

scholarly journals Hospital Construction Cost Affecting Their Lifecycle: An Italian Overview

Healthcare ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 888
Author(s):  
Leopoldo Sdino ◽  
Andrea Brambilla ◽  
Marta Dell’Ovo ◽  
Benedetta Sdino ◽  
Stefano Capolongo
Keyword(s):  
Healthcare Services ◽  
Construction Cost ◽  
Design Stage ◽  
Quality Healthcare ◽  
Healthcare Facilities ◽  
Early Design Stage ◽  
Hospital Facility ◽  
Italian Context ◽  
The Cost ◽  
Cost Components

The need for 24/7 operation, and the increasing requests of high-quality healthcare services contribute to framing healthcare facilities as a complex topic, also due to the changing and challenging environment and huge impact on the community. Due to its complexity, it is difficult to properly estimate the construction cost in a preliminary phase where easy-to-use parameters are often necessary. Therefore, this paper aims to provide an overview of the issue with reference to the Italian context and proposes an estimation framework for analyzing hospital facilities’ construction cost. First, contributions from literature reviews and 14 case studies were analyzed to identify specific cost components. Then, a questionnaire was administered to construction companies and experts in the field to obtain data coming from practical and real cases. The results obtained from all of the contributions are an overview of the construction cost components. Starting from the data collected and analyzed, a preliminary estimation tool is proposed to identify the minimum and maximum variation in the cost when programming the construction of a hospital, starting from the feasibility phase or the early design stage. The framework involves different factors, such as the number of beds, complexity, typology, localization, technology degree and the type of maintenance and management techniques. This study explores the several elements that compose the cost of a hospital facility and highlights future developments including maintenance and management costs during hospital facilities’ lifecycle.

scholarly journals Development of Filters with Minimal Hydraulic Resistance for Underground Water Intakes

2020 ◽  
Vol 6 (5) ◽  
pp. 919-927
Author(s):  
A. A. Akulshin ◽  
N. V. Bredikhina ◽  
An. A. Akulshin ◽  
I. Y. Aksenteva ◽  
N. P. Ermakova
Keyword(s):  
Hydraulic Resistance ◽  
Cross Section ◽  
High Performance ◽  
Underground Water ◽  
Performance Characteristics ◽  
Design Stage ◽  
Performance Loss ◽  
Filter Performance ◽  
Optimal Section ◽  
The Cost

The development of modern structures of water wells filtering equipment with enhanced performance characteristics is a vital task. The purpose of this work was to create filters for taking water from underground sources that have high performance, long service life, quickly and economically replace or repair in case of performance loss. The selection of the filter device must be made taking into account all the geological features of the aquifers, the performance characteristics of the filter devices and the size of the future structure. Filter equipment designs for water intake wells have been developed in this study. These filters have low hydraulic resistance, high performance and are easy to repair. This article presents the dependency of flow inside the receiving part of the well, the dependence of filter resistance at various forms of the cross section of the filter wire and the selected optimal section. The paper proposes a method for selecting the optimal cross-section of the filter wire used in the manufacture of a water well filter. The proposed structures of easy-to-remove well filters with increased productivity allow replacing the sealed well filter with a new one easily, reducing capital and operating costs, and increasing the inter-repair periods of their operation. Based on the presented method, examples are given for selecting the parameters of the filter wire cross-section. The above calculations showed that the use of the hydraulic resistance criterion at the design stage of underground water intakes can significantly reduce the cost of well construction. Studies have found that the minimum hydraulic resistance to ensure maximum filter performance is achieved when using filter wire teardrop and elliptical shapes.

scholarly journals Design of Multiple Mailboxes

2020 ◽  
Vol 318 ◽  
pp. 01041
Author(s):  
Athena Baronos ◽  
Odysseas Manoliadis ◽  
Aristeidis Pavlidis
Keyword(s):  
3D Visualization ◽  
Building Blocks ◽  
Design Stage ◽  
Extensive Literature ◽  
3D Design ◽  
3D Cad ◽  
Domestic Use ◽  
The Right ◽  
The Cost ◽  
Apartment Complexes

In today’s world the design of multiple mailboxes comes to cover the evolution of logistics in delivering mail where the postman is not required to visit every user. In this research the 3D visualization is used for the design of multiple mailboxes for domestic use. It concerns the design of mailboxes in ergonomic building blocks and apartment complexes in 3D design so that they can be easily manufactured. Between the advantages of this design will be rapid production of ready-made products production of prototypes that enables testing at the design stage and reduces the time and the cost of production. The design when done with 3D CAD can be manufactured with modern machine tooling methods. In this paper after an extensive Literature Review the postal multiple mailboxes is used as a case study in the use of 3D CAD for 3D printing. A methodology is proposed that enables the examination of prototypes at the design stage according to specifications and allows the manufacturing department of a company to prepare the right tools and begin installing production lines. Conclusively this method gives the advantage of designing the product and supporting the production of scaffolds that can be functionally and ergonomically tested before finalizing the production.

Design to First Deployment: Pressure-Activated Sliding Sleeve for Single-Trip Completion

2021 ◽  
pp. 1-14
Author(s):  
Ashutosh Dikshit ◽  
Amrendra Kumar ◽  
Glenn Woiceshyn
Keyword(s):  
Computer Aided Design ◽  
Failure Modes ◽  
Cost Savings ◽  
Lessons Learned ◽  
Design Stage ◽  
Coiled Tubing ◽  
Side Door ◽  
Safety Risks ◽  
Sand Control ◽  
The Cost

Summary Interest is high in a method to reliably run single-trip completions without involving complex/expensive technologies (Robertson et al. 2019). The reward for such a design would be reduced rig time, safety risks, and completion costs. As described herein, a unique pressure-activated sliding side door (PSSD) valve was developed and field tested to open without intervention after completion is circulated to total depth (TD) and a liner hanger and openhole isolation packers are set. A field-provensliding-sleeve door (SSD) valve that required shifting via a shifting tool run on coiled tubing, slickline (SL), or wireline was upgraded to open automatically after relieving tubing pressure once packers (and/or a liner hanger) are set. This PSSD technology, which is integrable to almost any type of sand control screen, is equipped with a backup contingency should the primary mechanism fail to open. Once opened, the installed PSSDs can be shifted mechanically with unlimited frequency. The two- or three-position valve can be integrated with inflow control devices (ICDs) (includes autonomous ICDs/autonomous inflow control valves) and allows mechanical shifting at any time after installation to close, stimulate or adjust ICD settings. After a computer-aided design stage to achieve all the operational/mechanical requirements, prototypes were built and tested, followed by field installations. The design stage provided some challenges even though the pressure-activation feature was being added to a mature/proven SSD technology. Prototype testing in a full-scale vertical test well proved valuable because it revealed failure modes that could not have appeared in the smaller-scale laboratory test facilities. Lessons learned from the first field trial helped improve onsite handling procedures. The production logging tool run on first installation confirmed the PSSDs with ICDs opened as designed. The second field installation involved a different size and configuration, in which PSSDs with ICDs performed as designed. The unique two- or three-position PSSD accommodates any type of sand control or debris screen and any type of ICD for production/injection. The PSSD allows the flexibility to change ICD size easily at the wellsite. Therefore, this technology can be used in carbonate as well as sandstone wells. Wells that normally could not justify the expense of existing single-trip completion technologies can now benefit from the cost savings of single-trip completions, including ones that require ICD and stimulation options.

Closed-loop Stability Analysis of DC / DC Converter with Input Filter

2020 ◽  
Author(s):  
Zhisong Lin ◽  
Yong Liu ◽  
Xiaobin He ◽  
Wei Xie ◽  
Mengxue Dong ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Closed Loop ◽  
Input Filter ◽  
Loop Stability

Model Predictive Control and Controller Parameter Optimisation of Combustion Instabilities

2019 ◽  
Vol 36 (2) ◽  
pp. 185-194 ◽  
Author(s):  
I. Yazar ◽  
F. Caliskan ◽  
R. Vepa
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Closed Loop ◽  
Combustion Process ◽  
Open Loop ◽  
Loop Model ◽  
Parameter Optimisation ◽  
Direct Adaptive Control ◽  
The Cost ◽  
Adaptive Control Algorithm

Abstract In this paper the application of model predictive control (MPC) to a two-mode model of the dynamics of the combustion process is considered. It is shown that the MPC by itself does not stabilize the combustor and the control gains obtained by applying the MPC algorithms need to be optimized further to ensure that the phase difference between the two modes is also stable. The results of applying the algorithm are compared with the open loop model amplitude responses and to the closed loop responses obtained by the application of a direct adaptive control algorithm. It is shown that the MPC coupled with the cost parameter optimisation proposed in the paper, always guarantees the closed loop stability, a feature that may not always be possible with an adaptive implementations.

Automatic Geometric Recognition of Weld Beads for Supporting Virtual Prototyping and Cost Estimation of Welding

2012 ◽  
Author(s):  
Roberto Raffaeli ◽  
Marco Malatesta ◽  
Marco Mandolini ◽  
Michele Germani
Keyword(s):  
Cost Estimation ◽  
Virtual Prototyping ◽  
Design Stage ◽  
Sheet Metal Parts ◽  
Geometric Size ◽  
Cad Models ◽  
Time Savings ◽  
Definition Of ◽  
The Cost ◽  
3D Solid

Welding is widely used in industry for products made of joined sheet metal parts and beams. The virtual prototyping process of welds in standard CAD systems relies on functionalities to manually add weld beads to the assembly models. Weld beads can be in the form of symbolic annotations or 3D solid representations. The size of products in terms of number of parts and required weld beads makes this process cumbersome and time consuming. This paper presents a method to analyze CAD models of product assemblies in order to automatically identify possible welds among the parts using geometric recognition rules. Adjacent faces are detected and Boolean operators on planar loops are used to identify bead paths. Beads are then split in homogeneous portions based on the topology of the connected parts. The geometrical analysis of the connected parts also allows a bead to be characterized in terms of thickness, type, length and accessibility. Finally, the user is provided with functionalities to edit manufacturing properties or exclude unwanted welds. The approach is applied at the design stage to rapidly come to the definition of the welds. If integrated with a CAD tool, this can be used as input for an efficient detailing phase. Moreover, the paper presents an application for the cost estimation of the designed welded product. Weld beads are given a realization time, and hence a cost, based on their geometric size and employed welding technology. Some examples from the industry are presented to show benefits in terms of time savings and accuracy of the cost estimation process.

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