scholarly journals Study and Implementation of a Cost-Effective 3L-Active Rectifier for DC Collection in WECS

2019 ◽  
Vol 118 ◽  
pp. 02065
Author(s):  
Muhammad Luqman ◽  
Gang Yao ◽  
Lidan Zhou ◽  
Di Yang ◽  
Anil Lamichhane
Keyword(s):  
Low Cost ◽  
Cost Effective ◽  
Cost Comparison ◽  
Multilevel Converters ◽  
Wind Generators ◽  
Active Rectifier ◽  
Vienna Rectifier ◽  
Three Phase ◽  
Control Scheme ◽  
Parallel Configuration

Power electronic converters are widely used in wind energy conversion system (WECS) applications. Therefore, with the increasing manufacturing capacity of multi-MW wind generators, multi-level converters, or parallel configuration of converters are becoming more attractive solutions towards DC collection from the wind generator. Among the multilevel converters, three-level full-scale neutral point diode clamped (3L-NPC) converter are using extensively for such applications in order to reduce the voltage stress on the semiconductor devices. In this article, a comparative study based on several devices used by NPC, capacitor clamped (CC) as well as Vienna rectifier has been done. Furthermore, their estimated cost comparison and complexity of control switches have been debated. By keeping in view the merits and demerits of these rectifiers, a low cost three-level active rectifier having a smaller number of active switches with a simple control scheme have been implemented. Considering a three-phase electric grid as a generated source, a 2.2KW low-cost three-level Vienna rectifier is simulated using MATLAB/Simulink. DSP (TMS320F28335) based experimental results ratify the simulated circuit with THD<5%.

scholarly journals Application of Simplified Neutral Point Clamped Multilevel Converter in a Small Wind Turbine

2014 ◽  
Vol 5 (1) ◽  
pp. 5-10 ◽  
Author(s):  
Pawel Mlodzikowski ◽  
Adam Milczarek ◽  
Mariusz Malinowski
Keyword(s):  
Low Cost ◽  
Direct Torque Control ◽  
Synchronous Generator ◽  
Neutral Point ◽  
Torque Control ◽  
Multilevel Converters ◽  
Laboratory Setup ◽  
Power Modules ◽  
Control Scheme ◽  
Clamped Converter

Abstract In low power distributed generation systems low cost together with the energy quality requirements are a key element. It is known that quality of voltage waveforms generated from multilevel converters is better in comparison with those from two-level. Due to advancements in power electronics and microcontrollers, multilevel converters are being built with the use of integrated power modules thus this type of converters are getting more compact in size. This paper investigates performance of a derivation from the most popular multilevel topology - a neutral point clamped converter (NPC). Applying the idea for simplifying the topology by reducing the number of switches (what came from drives) this NPC converter is capable of bidirectional AC/DC/AC operation. For the AC/DC part two schemes are tested: Direct Torque Control Space Vector Modulated and Field Oriented Control but for the DC/AC part a control scheme utilizing the proportional-resonant controller was chosen. Laboratory setup was based on a permanent magnet synchronous generator with control and acquisition completed with the help of dSpace 1005 control box. Experimental verification shows that system operates properly.

scholarly journals Cost comparison of different treatment approaches of dacryocystitis and dacrocystocele

2020 ◽  
Vol 12 ◽  
pp. 251584142092628
Author(s):  
Erin G. Sieck ◽  
Leonid Zukin ◽  
Jennifer L. Patnaik ◽  
Anne M. Lynch ◽  
Peggy Kelley ◽  
...  
Keyword(s):  
Chart Review ◽  
Low Cost ◽  
Operating Time ◽  
Cost Benefit ◽  
Retrospective Chart Review ◽  
Cost Effective ◽  
Nasolacrimal Duct ◽  
Cost Comparison ◽  
Nasal Endoscopy ◽  
Surgical Approaches

Purpose: Congenital dacrocystocele with potential for dacryocystitis are common ophthalmic findings in children. There are multiple surgical approaches to open the mucocele. In this study, we look at the financial impact of these different approaches. Methods: A retrospective chart review of 17 patients with dacrocystocele or dacryocystitis was performed. We examined four approaches: (1) bedside nasal endoscopy with marsupialization of nasolacrimal duct (NLD) cyst, (2) surgically performed nasal endoscopy with marsupialization of NLD cyst, (3) NLD probe, and (4) a combination of procedures. Cost of the procedure and length of anesthesia were collected. Reoccurrence of symptoms and disease post-procedure were also collected. Results: The lowest cost billed procedure was bedside nasal endoscopy performed by an otolaryngologist (US$435; n = 1). A nasal endoscopy ( n = 2) performed in the operating room (OR) had an average OR fee of US$14,557 [standard deviation (SD): US$7598] for 108.5 (SD: 87.0) min of operating time. An NLD probe ( n = 5) performed by pediatric ophthalmologists resulted in an average OR fee of US$5540 (SD: US$1752) for 31.0 min (SD: 8.6 min) of operating time. A combination of both nasal endoscopy and NLD probing ( n = 9) had an average OR fee US$10,325 (SD: US$4137) for 69 min (SD: 34.5 min) of operating time. Conclusion: This is the first study looking at cost benefit of four different approaches to treating dacrocystoceles/dacryocystitis. A NLD probe was a low-cost OR intervention and had the shortest operating time. The combination procedure was more cost-effective than nasal endoscopy or NLD probing alone.

scholarly journals Cost-Effective Power Converters for Small Wind Turbines

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5906
Author(s):  
Sławomir Karyś ◽  
Paweł Stawczyk
Keyword(s):  
Wind Turbines ◽  
Power Converters ◽  
Low Cost ◽  
Cost Effective ◽  
Control Methods ◽  
Three Phase ◽  
Small Wind Turbines ◽  
Simulation Results ◽  
And Control ◽  
First Time

This paper presents AC/DC converters for cost-effective small wind turbine systems. The analysis focuses on reliable, sensor-less, and low-cost solutions. A recently developed type of the three phase AC/DC two-switch converter is compared, for the first time, using simulations and experiments, with two other converters. The operating principles and control methods are discussed. Simulation results are verified experimentally and interesting conclusions are drawn. It is shown that less known converters are also attractive solutions for use in small wind turbines.

ASSESSMENT OF THE PLATELET COUNT IN THE PREGNANT WOMEN IN IGIMS, PATNA, BIHAR

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Tanwi Singh ◽  
Anshuman Sinha
Keyword(s):  
Platelet Count ◽  
Pregnant Women ◽  
Screening Test ◽  
Low Cost ◽  
Medical Science ◽  
Cost Effective ◽  
Platelet Indices ◽  
Increased Risk ◽  
Low Platelet Count ◽  
Severity Of The Disease

The major risk associated with low platelet count in pregnancy is the increased risk of bleeding during the childbirth or post that. There is an increased blood supply to the uterus during pregnancy and the surgical procedure requires cutting of major blood vessels. Women with thrombocytopenia are at increased risk of losing excessive blood. The risk is more in case of caesarean delivery as compared to vaginal delivery. Hence based on above findings the present study was planned for Assessment of the Platelet Count in the Pregnant Women in IGIMS, Patna, Bihar. The present study was planned in Department of Pathology, Indira Gandhi Institute of Medical Science, Patna, Bihar, India. The present study was planned from duration of January 2019 to June 2019. In the present study 200 pregnant females samples received for the platelet estimation were enrolled in the present study. Clinically platelet indices can be a useful screening test for early identification of preeclampsia and eclampsia. Also platelet indices can assess the prognosis of this disease in pregnant women and can be used as an effective prognostic marker because it correlates with severity of the disease. Platelet count is a simple, low cost, and rapid routine screening test. Hence the data generated from the present study concludes that platelet count can be used as a simple and cost effective tool to monitor the progression of preeclampsia, thereby preventing complications to develop during the gestational period. Keywords: Platelet Count, Pregnant Women, IGIMS, Patna, Bihar, etc.

Advance Protection for Three Phase Induction Motor using Microcontroller Atmega32

2018 ◽  
Vol 8 (1) ◽  
pp. 172
Author(s):  
Karan S Belsare ◽  
Gajanan D Patil
Keyword(s):  
Induction Motor ◽  
Low Cost ◽  
Short Circuit ◽  
Cost Factor ◽  
Protection Scheme ◽  
Three Phase ◽  
The Cost

A low cost and reliable protection scheme has been designed for a three phase induction motor against unbalance voltages, under voltage, over voltage, short circuit and overheating protection. Taking the cost factor into consideration the design has been proposed using microcontroller Atmega32, MOSFETs, relays, small CTs and PTs. However the sensitivity of the protection scheme has been not compromised. The design has been tested online in the laboratory for small motors and the same can be implemented for larger motors by replacing the i-v converters and relays of suitable ratings.

Janus – A New Approach to Air Combat Pilot Training

2019 ◽  
Vol 2019 (4) ◽  
pp. 7-22
Author(s):  
Georges Bridel ◽  
Zdobyslaw Goraj ◽  
Lukasz Kiszkowiak ◽  
Jean-Georges Brévot ◽  
Jean-Pierre Devaux ◽  
...  
Keyword(s):  
Low Cost ◽  
Cost Effective ◽  
High Energy ◽  
Training System ◽  
Embedded Sensors ◽  
Pilot Training ◽  
New Approach ◽  
Combat Aircraft ◽  
Air Combat ◽  
The Cost

Abstract Advanced jet training still relies on old concepts and solutions that are no longer efficient when considering the current and forthcoming changes in air combat. The cost of those old solutions to develop and maintain combat pilot skills are important, adding even more constraints to the training limitations. The requirement of having a trainer aircraft able to perform also light combat aircraft operational mission is adding unnecessary complexity and cost without any real operational advantages to air combat mission training. Thanks to emerging technologies, the JANUS project will study the feasibility of a brand-new concept of agile manoeuvrable training aircraft and an integrated training system, able to provide a live, virtual and constructive environment. The JANUS concept is based on a lightweight, low-cost, high energy aircraft associated to a ground based Integrated Training System providing simulated and emulated signals, simulated and real opponents, combined with real-time feedback on pilot’s physiological characteristics: traditionally embedded sensors are replaced with emulated signals, simulated opponents are proposed to the pilot, enabling out of sight engagement. JANUS is also providing new cost effective and more realistic solutions for “Red air aircraft” missions, organised in so-called “Aggressor Squadrons”.

Identificación de polaridad de los devanados en un motor trifásico de 6 terminales

2019 ◽  
pp. 13-19
Author(s):  
José Luis Viramontes-Reyna ◽  
Josafat Moreno-Silva ◽  
José Guadalupe Montelongo-Sierra ◽  
Erasmo Velazquez-Leyva
Keyword(s):  
Low Cost ◽  
Voltage Reference ◽  
Three Phase ◽  
Voltage Phase ◽  
The Law ◽  
And Control

This document presents the results obtained from the application of the law of Lens to correctly identify the polarity of the windings in a three-phase motor with 6 exposed terminals, when the corresponding labeling is not in any situation; Prior to identifying the polarity, it should be considered to have the pairs of the three windings located. For the polarity, it is proposed to feed with a voltage of 12 Vrms to one of the windings, which are identified randomly as W1 and W2, where W1 is connected to the voltage phase of 12 Vrms of the signal and W2 to the voltage reference to 0V; by means of voltage induction and considering the law of Lens, the remaining 4 terminals can be identified and labeled as V1, V2, U1 and U2. For this process a microcontroller and control elements with low cost are used.

Motivating Compliance: Firm Response to Mandatory Disclosure Policies

2018 ◽  
Vol 32 (2) ◽  
pp. 103-119
Author(s):  
Colleen M. Boland ◽  
Chris E. Hogan ◽  
Marilyn F. Johnson
Keyword(s):  
Conflict Of Interest ◽  
Low Cost ◽  
Cost Effective ◽  
Data Availability ◽  
Policy Adoption ◽  
Future Research ◽  
Regulated Firms ◽  
Firm Response ◽  
Disclosure Rules ◽  
The Impact

SYNOPSIS Mandatory existence disclosure rules require an organization to disclose a policy's existence, but not its content. We examine policy adoption frequencies in the year immediately after the IRS required mandatory existence disclosure by nonprofits of various governance policies. We also examine adoption frequencies in the year of the subsequent change from mandatory existence disclosure to a disclose-and-explain regime that required supplemental disclosures about the content and implementation of conflict of interest policies. Our results suggest that in areas where there is unclear regulatory authority, mandatory existence disclosure is an effective and low cost regulatory device for encouraging the adoption of policies desired by regulators, provided those policies are cost-effective for regulated firms to implement. In addition, we find that disclose-and-explain regulatory regimes provide stronger incentives for policy adoption than do mandatory existence disclosure regimes and also discourage “check the box” behavior. Future research should examine the impact of mandatory existence disclosure rules in the year that the regulation is implemented. Data Availability: Data are available from sources cited in the text.

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