scholarly journals Are Inductive Current Transformers Performance Really Affected by Actual Distorted Network Conditions? An Experimental Case Study

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 927 ◽  
Author(s):  
Alessandro Mingotti ◽  
Lorenzo Peretto ◽  
Lorenzo Bartolomei ◽  
Diego Cavaliere ◽  
Roberto Tinarelli
Keyword(s):  
Operating Conditions ◽  
Accuracy Evaluation ◽  
Current Transformers ◽  
Need To Evaluate ◽  
Instrument Transformers ◽  
Instrument Transformer ◽  
Secondary Result ◽  
Error Index ◽  
Accuracy Performance

The aim of this work is to assess whether actual distorted conditions of the network are really affecting the accuracy of inductive current transformers. The study started from the need to evaluate the accuracy performance of inductive current transformers in off-nominal conditions, and to improve the related standards. In fact, standards do not provide a uniform set of distorted waveforms to be applied on inductive or low-power instrument transformers. Moreover, there is no agreement yet, among the experts, about how to evaluate the uncertainty of the instrument transformer when the operating conditions are different from the rated ones. To this purpose, the authors collected currents from the power network and injected them into two off-the-shelf current transformers. Then, their accuracy performances have been evaluated by means of the well-known composite error index and an approximated version of it. The obtained results show that under realistic non-rated conditions of the network, the tested transformers show a very good behavior considering their nonlinear nature, arising the question in the title. A secondary result is that the use of the composite error should be more and more supported by the standards, considering its effectiveness in the accuracy evaluation of instrument transformers for measuring purposes.

scholarly journals On the Long-Period Accuracy Behavior of Inductive and Low-Power Instrument Transformers

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5810
Author(s):  
Alessandro Mingotti ◽  
Lorenzo Bartolomei ◽  
Lorenzo Peretto ◽  
Roberto Tinarelli
Keyword(s):  
Low Power ◽  
Accuracy Evaluation ◽  
Power Network ◽  
Critical Aspect ◽  
Long Period ◽  
Instrument Transformers ◽  
Instrument Transformer ◽  
Control And Management

The accuracy evaluation of instrument transformers is always a key task when proper control and management of the power network is required. In particular, accuracy becomes a critical aspect when the grid or the instrumentation itself is operating at conditions different from the rated ones. However, before focusing on the above non-rated conditions, it is important to fully understand the instrument transformer behavior at rated conditions. To this end, this work analyzed the accuracy behavior of legacy, inductive, and low-power voltage transformers over long periods of time. The aim was to find patterns and correlations that may be of help during the modelling or the output prediction of voltage transformers. From the results, the main differences between low-power and inductive voltage transformers were pointed out and described in detail.

scholarly journals Optimised calibration programmes for comparators for instrument transformers

2021 ◽  
Vol 88 (2) ◽  
pp. 122-131
Author(s):  
Christian Mester
Keyword(s):  
Experimental Study ◽  
Operating Principle ◽  
Device Under Test ◽  
Operating Range ◽  
Ratio Error ◽  
Phase Displacement ◽  
Instrument Transformers ◽  
Instrument Transformer ◽  
Method Of Measurement

Abstract Traditionally, instrument transformers are calibrated using bridges. By definition, bridges use the null method of measurement. The traditional calibration programme for instrument transformer bridges characterise namely this null measurement. Many new commercial comparators for instrument transformer use a very different method. They sample the secondary signals of reference and device under test (dut) transformer independently. Based on the samples, magnitude and phase of both signals are determined. Ratio error and phase displacement are calculated. Consequently, the significance of their calibration using the traditional calibration programme is limited. Moreover, the operating range of modern comparators is much larger than that of bridges. The additional versatility cannot be used without an adapted calibration programme. This article analyses the calibration programmes for both technologies. An experimental study confirms both the suitability of the new calibration programme and the need to chose the calibration programme depending on the technology of the device to be calibrated. The conclusion is very general and applies to all measurement problems where an operating principle is replaced by another – when changing the operating principle, it is important to check the calibration programme and adapt it if necessary.

Comparative study of i-SENS glucometers in neonates using capillary blood samples

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ha Nui Kim ◽  
Soo-Young Yoon
Keyword(s):  
Reference Values ◽  
Point Of Care ◽  
Evaluation Process ◽  
Capillary Blood ◽  
Performance Criteria ◽  
Accuracy Evaluation ◽  
Blood Samples ◽  
Average Reference ◽  
Error Grid ◽  
Accuracy Performance

Abstract Objectives The accuracy of point-of-care blood glucometers in the detection and evaluation of neonatal hypoglycemia is a concern. This study compared the performance of three i-SENS glucometers with that of the YSI 2300 STAT Plus Analyzer, which was used as a reference. Methods The leftover neonatal capillary blood samples of 319 patients were used in this study. The evaluation process and accuracy performance criteria were based on the International Organization for Standardization 15197:2013 guidelines. The evaluation involved three i-SENS glucometers (BAROzen H Expert plus, CareSens PRO, and CareSens H Beat) and the ACCU-CHEK® Inform II glucometer. Results The accuracy evaluation yielded acceptable results as follows: a) 100 and 100% for BAROzen H Expert plus; 99.8 and 100% for CareSens PRO; 98.7%, and 97.2% for CareSens H Beat glucometers were within the range of ±0.8 mmol/L (15 mg/dL) and ±15% of the average reference values at glucose concentrations <5.55 mmol/L (100 mg/dL) and ≥5.55 mmol/L (100 mg/dL), respectively, and b) all estimated glucose values (100%) were within the zones A and B of Consensus Error Grid for all three i-SENS glucometers. There was good correlation between the glucose values estimated by the glucometers and the reference values (R>0.990). Conclusions This study demonstrated that i-SENS glucometers exhibit acceptable performance and can be used as effective point-of-care devices in neonates.

A Practical Approach to Expedite a Pore to Process Simulation Model for a Rich Gas Condensate Reservoir – Case Study

2021 ◽  
Author(s):  
Mohamed Ibrahim Mohamed ◽  
Ahmed Mahmoud El-Menoufi ◽  
Eman Abed Ezz El-Regal ◽  
Ahmed Mohamed Ali ◽  
Khaled Mohamed Mansour ◽  
...  
Keyword(s):  
Simulation Model ◽  
Production Optimization ◽  
Operating Conditions ◽  
Gas Condensate ◽  
Western Desert ◽  
Design Parameters ◽  
Compositional Approach ◽  
Process Plant ◽  
Black Oil

Abstract Field development planning of gas condensate fields using numerical simulation has many aspects to consider that may lead to a significant impact on production optimization. An important aspect is to account for the effects of network constraints and process plant operating conditions through an integrated asset model. This model should honor proper representation of the fluid within the reservoir, through the wells and up to the network and facility. Obaiyed is one of the biggest onshore gas field in Egypt, it is a highly heterogeneous gas condensate field located in the western desert of Egypt with more than 100 wells. Three initial condensate gas ratios are existing based on early PVT samples and production testing. The initial CGRs as follows;160, 115 and 42 STB/MMSCF. With continuous pressure depletion, the produced hydrocarbon composition stream changes, causing a deviation between the design parameters and the operating parameters of the equipment within the process plant, resulting in a decrease in the recovery of liquid condensate. Therefore, the facility engineers demand a dynamic update of a detailed composition stream to optimize the system and achieve greater economic value. The best way to obtain this compositional stream is by using a fully compositional integrated asset model. Utilizing a fully compositional model in Obaiyed is challenging, computationally expensive, and impractical, especially during the history match of the reservoir numerical model. In this paper, a case study for Obaiyed field is presented in which we used an alternative integrated asset modeling approach comprising a modified black-oil (MBO) that results in significant timesaving in the full-field reservoir simulation model. We then used a proper de-lumping scheme to convert the modified black oil tables into as many components as required by the surface network and process plant facility. The results of proposed approach are compared with a fully compositional approach for validity check. The results clearly identified the system bottlenecks. The model can be used to propose the best tie-in location of future wells in addition to providing first-pass flow assurance indications throughout the field's life and under different network configurations. The model enabled the facility engineers to keep the conditions of the surface facility within the optimized operating envelope throughout the field's lifetime.

scholarly journals A Participatory Action Research Method in a Rural Community of Mexico

2016 ◽  
Vol 14 (4) ◽  
pp. 1197 ◽  
Author(s):  
Rubi Arellano ◽  
Fabricio Balcazar ◽  
Sergio Suarez ◽  
Francisco Alvarado
Keyword(s):  
Action Research ◽  
Participatory Action Research ◽  
Social Services ◽  
Community Interventions ◽  
Participatory Action ◽  
Community Members ◽  
Need To Evaluate ◽  
Community Issues ◽  
To Come

For several decades, community interventions have promoted community development with strategies involving capacity building, advocacy, social change, and empowerment. Although community interventions intend to ameliorate social and economic inequalities, there is still a need to evaluate the outcomes of Participatory Action Research (PAR). PAR approaches have demonstrated to be a helpful tool for addressing and identifying community issues and strengths, while leading community members into action. The PAR approach described in this case study of “Ciudad Renace” (Town Reborn)—the Concerns Report Method (CRM)—provided a process for the community to come together and identify main issues, organize, and take actions. The findings suggest multiple activities and outcomes in areas like environmental contamination, social services, and education. Participatory methodologies like the Concerns report Method provided opportunities for community members to become engaged in pursing issues and addressing their own needs. The implications for community psychology research and practice are discussed.

scholarly journals Thermo-economic analysis and optimization of the steam absorption chiller network plant

2021 ◽  
pp. 58-58
Author(s):  
Farshad Panahizadeh ◽  
Mahdi Hamzehei ◽  
Mahmood Farzaneh-Gord ◽  
Villa Ochoa
Keyword(s):  
Economic Analysis ◽  
Working Condition ◽  
Search Algorithm ◽  
Deep Understanding ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Absorption Chiller ◽  
Absorption Chillers ◽  
Optimization Search

Absorption chillers are one of the most used equipment in industrial, commercial, and domestic applications. For the places where high cooling is required, they are utilized in a network to perform the cooling demand. The main objective of the current study was to find the optimum operating conditions of a network of steam absorption chillers according to energy and economic viewpoints. Firstly, energy and economic analysis and modeling of the absorption chiller network were carried out to have a deep understanding of the network and investigate the effects of operating conditions. Finally, the particle swarm optimization search algorithm was employed to find an optimum levelized total costs of the plant. The absorption chiller network plant of the Marun Petrochemical Complex in Iran was selected as a case study. To verify the simulation results, the outputs of energy modeling were compared with the measured values. The comparison with experimental results indicated that the developed model could predict the working condition of the absorption chiller network with high accuracy. The economic analysis results revealed that the levelized total costs of the plant is 1730 $/kW and the payback period is three years. The optimization findings indicated that working at optimal conditions reduces the levelized total costs of the plant by 8.5%, compared to the design condition.

Implementing a Website Portal Using PortfolioVillage.com to Evaluate Professional Credentials

2012 ◽  
pp. 308-317 ◽  
Author(s):  
John DiMarco
Keyword(s):  
Professional Development ◽  
Job Applicants ◽  
Web Portal ◽  
Technology Leaders ◽  
Need To Evaluate

This chapter offers suggestions and discussion on implementing a website portal to create e-portfolios and Web portfolios. The need to evaluate professional credentials is evident in academia and business, especially for technology leaders assessing whether learning has occurred through professional development. The e-portfolio/Web portfolio has promise as a platform for assessment of students, employees, faculty, and job applicants. Navigating decisions on Web portal solutions and systems can be difficult due to the varying needs of administrative and academic stakeholders. This chapter includes a brief case study discussion of a portfolio portal project and an overview of the various tools available, which is focused on providing insight to technology leaders.

scholarly journals PQ and Harmonic Assessment Issues on Low-Cost Smart Metering Platforms: A Case Study

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6361
Author(s):  
Giovanni Artale ◽  
Giuseppe Caravello ◽  
Antonio Cataliotti ◽  
Valentina Cosentino ◽  
Dario Di Cara ◽  
...  
Keyword(s):  
Power Quality ◽  
Feasibility Study ◽  
Low Voltage ◽  
Low Cost ◽  
Distribution Networks ◽  
Smart Metering ◽  
Energy Metering ◽  
Instrument Transformers ◽  
The Impact

This paper presents a feasibility study on how to implement power quality (PQ) metrics in a low-cost smart metering platform. The study is aimed at verifying the possibility of implementing PQ monitoring in distribution networks without replacing existing smart metering devices or adding new modules for PQ measurements, thus zeroing the installation costs. To this aim, an electronic board, currently used for remote energy metering, was chosen as a case study, specifically the STCOMET platform. Starting from the specifications of this device, the possibility of implementing power quality metrics is investigated in order to verify if compliance with standard requirements for PQ instruments can be obtained. Issues related to device features constraints are discussed; possible solutions and correction algorithms are presented and experimentally verified for different PQ metrics with a particular focus on harmonic analysis. The feasibility study takes into account both the use of on-board voltage and current transducers for low voltage applications and also the impact of external instrument transformers on measurement results.

Sign in / Sign up

Export Citation Format

Share Document