AMR System Research Articles

A numerical comparison of Gd, Pr0.65Sr0.35MnO3 and single LaFeCoSi for use in a magnetic refrigeration.

Abstract One of the most significant scientific difficulties to achieving excellent performance for room-temperature magnetic cooling devices is finding suitable magnetocaloric refrigerants. To contribute to this research field, three kinds of magnetocaloric materials (Gd, Pr0.65Sr0.35MnO3 and single LaFeCoSi) in the same conditions (Curie temperature, applied magnetic field) have been considered to evaluate their potential in the magnetic refrigeration application using a 1D-AMRR (Active-Magnetic-Refrigeration-Regenerator) cycle with a parallel plate regenerator. In this way, four cooling performance parameters were investigated, namely the temperature span, the cooling power, the exergy, and the coefficient of performance. The temperature span was found to be 11.79K for Gd , 8K for LaFeCoSi and 4.47 K for Pr0.65Sr0.35MnO3. The obtained numerical results reveal that the Gd-based AMR system displays a higher efficiency, while the Pr0.65Sr0.35MnO3-based AMR system exhibits a smaller one. The magnetocaloric effect (MCE) in the magnetic refrigerants was considered to explain the result obtained and can be considered as one of the main factors to enhance the magnetic refrigeration performance.

Numerical analysis for smaller entropy generation of micro-unit magnetic refrigerator at room temperature

Magnetic refrigeration (MR) is earning global attention for being a promising alternative for vapor compression refrigeration, due to its characteristic of being energy efficient and environmentally benign. Currently, the widely accepted active magnetic regeneration refrigeration (AMRR) technology is facing some inherent problems caused by using heat transfer fluid, thus fully solid-state MR is proposed to avoid those problems. Micro-unit regeneration (MUR) magnetic refrigeration is a typical kind of it. To compare those MR systems from a perspective of energy utilization efficiency, we combine entropy generation theory with MR theory to establish a new performance evaluation standard of irreversible energy loss. And we constructed the numerical models of both AMR (parallel-plate) and MUR systems for entropy generation comparison analysis. The results show that micro-unit regeneration magnetic refrigeration system owns a smaller systematic entropy generation rate than the AMR system under the selected working conditions. When those two systems provide a temperature span of 8 K, the MUR system's entropy generation rate S˙MUR,tot is 52% smaller than AMR, thus, the performance of MUR system is better. Subsequently, the optimized condition for MUR system is found (for heat regeneration time tlattice=9s and the number of units Nunit=72), the largest temperature span is acquired exactly when S˙MUR,tot is the smallest. The results of MUR system's partial entropy generation rate show that entropy generation caused by heat transfer between MCM units from different heat regenerators takes 60% of S˙MUR,tot, which can provide theoretical guidance for the subsequent optimization for heat transfer enhancement.

Comparative Study between precooled Claude Liquefaction Cycle and an Active Magnetic Regeneration Cycle applied to Hydrogen Liquefaction

The present work aims at performing a comparative study between precooled Claude cycle and an Active Magnetic Regeneration Cycle (AMR cycle) applied to hydrogen liquefaction. It deals with a comparison between performances and energy consumption evaluated for the two systems at similar operating conditions. For Claude system, energy and material balances have been performed by using Aspen Hysys simulator. Thus, liquefaction power, energy consumption and coefficient of performance (COP) have been calculated. While, the AMR system considered is constituted of 6 stages operating in cascade. Each stage contains two regenerator beds, composed of a typical magnetic material, through which a carrier fluid is forced to follow alternatively between two heat reservoirs. Thermal analysis and evaluation of performances have been performed at once by a numerical model, developed on the basis of energy equations for fluid and solid within the regenerator bed, and Aspen Hysys simulator. Using the following magnetic materials (Gd, Dy, Tb and Ho), the COP found for the AMR system is 0.096. This value is higher than Claude cycle efficiency for which a COP of 0.094 was found. In terms of energy consumption, the value found for the AMR cycle is 0.053 kW which can be neglected compared to the Claude cycle consumption (14.5 kW).

Analysis of Measurement Results on AMR to Determine P2TL Operation Targets at PT PLN (Persero) UP3 Indramayu

The Kwh Meter Automatic Meter Reading (Kwh Meter AMR) system is a system for recording electricity meters that is carried out automatically and remotely. Data communication sent by the AMR kWH meter at PT PLN (Persero) UP3 Indramayu uses an AMR modem as an electronic kWH meter interfacing with a wireless telecommunications network. The AMR kWh meter has a feature that besides recording the use of electrical energy used, it also records voltage, electric current, power factor, and the recording time of the customer's electricity usage meter is faster. PT PLN (Persero) UP3 Indramayu can carry out distribution network management which makes it easier in terms of distributing energy to customers and monitoring the use of electrical energy by customers. In operating the kWh meter AMR system can reduce losses caused by abnormal use of electrical energy by customers. These abnormalities include incorrect Wiring, errors in wiring on the Kwh Meter, Unbalance Current, unbalanced electricity usage by customers, Blank Kwh and AMR modem hangs/damages so that the communication signal is unstable and fails to retrieve data on electricity consumption by customers. To overcome these abnormalities, a check is carried out on the customer according to the findings of abnormal deviations in the AMR application. The use of unmeasured electrical energy during the Kwh Blank abnormality is 4,619 kWh with a total follow-up billing fee of Rp. 6,936,537.-. The results of the abnormality category of Incorrect Wiring were carried out by normalizing wiring errors in the Kwh Meter phase S and Phase T. The results of the Unbalance Current abnormality category, the electricity consumption at the customer at that time was not balanced, that is, the T phase was not used by the customer. The results of the AMR Modem abnormality category are replaced by the AMR Modem so that the customer's electricity consumption is again disabled in the AMR application.

Characterizing social-ecological context and success factors of antimicrobial resistance interventions across the One Health spectrum: analysis of 42 interventions targeting E. coli

BackgroundAntimicrobial resistance (AMR) is among the most pressing One Health issues. While interventions and policies with various targets and goals have been implemented, evidence about factors underpinning success and failure of interventions in different sectors is lacking. The objective of this study is to identify characteristics of AMR interventions that increase their capacity to impact AMR. This study focuses on AMR interventions targeting E. coli.MethodsWe used the AMR-Intervene framework to extract descriptions of the social and ecological systems of interventions to determine factors contributing to their success.ResultsWe identified 52 scientific publications referring to 42 unique E. coli AMR interventions. We mainly identified interventions implemented in high-income countries (36/42), at the national level (16/42), targeting primarily one sector of society (37/42) that was mainly the human sector (25/42). Interventions were primarily funded by governments (38/42). Most intervention targeted a low leverage point in the AMR system, (36/42), and aimed to change the epidemiology of AMR (14/42). Among all included publications, 55% (29/52) described at least one success factor or obstacle (29/52) and 19% (10/52) identified at least one success factor and one obstacle. Most reported success factors related to communication between the actors and stakeholders and the role of media, and stressed the importance of collaboration between disciplines and external partners. Described obstacles covered data quality, access to data and statistical analyses, and the validity of the results.ConclusionsOverall, we identified a lack of diversity regarding interventions. In addition, most published E. coli interventions were poorly described with limited evidence of the factors that contributed to the intervention success or failure. Design and reporting guidelines would help to improve reporting quality and provide a valuable tool for improving the science of AMR interventions.

Magnetic properties, magnetocaloric effect and cooling performance of AlFe[formula omitted]B[formula omitted] compound: Ab initio, Monte Carlo and numerical modeling study

The structural and electronic properties of AlFe2B2 compound have been investigated using ab initio calculations based on the Density Functional Theory (DFT) as implemented in the WIEN2k code. The magnetic exchange couplings have been calculated using SPRKKR code. Then, the magnetic and magnetocaloric properties have been studied using Monte Carlo simulation. The results confirm that the AlFe2B2 compound is ferromagnetic. In addition, AlFe2B2 exhibits a second-order magnetic phase transition at 290 K. For the magnetic field change of 0–5 T, the maximum values of the magnetic entropy change (-ΔSm), the adiabatic temperature change (ΔTad) and the relative cooling power (RCP) for AlFe2B2 are 7.65 J.kg−1, 3.84 K and 210 J.K−1 respectively. A 1D model of the AMR system has been developed. The model has been used to access the performance of AlFe2B2 in a packed-bed AMR. The results confirm that, the AlFe2B2 compound could be a promising candidate for magnetic refrigeration applications.

Идентификация утечек тока в распределительных сетях по данным АСКУЭ

An electric distribution network (EDN), functioning during the implementation of an AMR system is considered. It is assumed that the EDN operates in an asymmetric mode and is subject to the actions of random external factors. The latter includes, among others, the leakage currents, including unauthorized power outages in the network. An increase in the frequency of these disturbances leads to significant energy losses. The task to identify the leakage current in a three-phase network is set using the AMR data obtained from customer electri­city meters. A solution method is suggested, it is based on mathematical modeling of the disturbed and desired conditions of EDN. At the same time, the actual and potentially possible voltage increments are identified at the inter-customer sites of the three-phase network which are caused by current leakage. The mathematics, describing the functional connections between specified voltage increments and network parameters that are used to localize the current leakage coordinates has been obtained. The computational scheme of the proposed method is aimed to develop the algorithmic and special software for the subsystem of diagnostics of EDN in the structure of AMR.

Three-Meter AMR System with Grid Demand-Side Energy Management in Smart Home System

A remote AMR system based on a STC90C52AD microcontroller and wireless network technology is presented in this paper to solve the problems in existing AMR system. Based on Smart Home system with grid demand side energy management, the automatic meter reading system centralizes electric power, water, gas meters, provides remote real-time automatic meter reading services and give instruction suggestions which contribute to energy management. Through the Web application platform, the users can use the Internet, mobile phones and other means to achieve the remote monitoring of the household appliances, energy-saving and saving house electricity costs. This AMR system has been implemented successfully by the State Grid Corporation Shandong Electric Power Group Corporation and the department of Automation of Wuhan University in collaboration.

스마트 그리드를 위한 원격검침 표준 프로토콜 인증 시스템 구축과 표준화에 관한 연구

본 논문에서는 스마트 그리드의 대표적 서비스인 원격검침을 위한 국제 표준 프로토콜 DLMS(Device Language Message Specifications)의 도입에서부터 정착까지 한국전력공사의 원격검침 인증 시스템 구축내용과 연구개발의 현황을 살펴보고자 한다. 현재 운용 중인 55만 저압고객에 대한 고속 PLC를 활용한 원격검침 시스템은 전력회사의 자체 통신 인프라를 활용하여 고속 데이터 전송이 가능한 시스템으로써, 전 세계적으로도 사업화에 빠르게 적용한 케이스이다. 여기에는 국제 표준 기반 원격검침 프로토콜을 탑재한 전자식 전력량계와 원격검침 핵심 기기 간 프로토콜의 적합성을 평가하기 위한 인증 시스템의 적기 구축이 큰 성공요인으로 볼 수 있다. 이처럼 한국전력공사에서는 DLMS 표준 기반 인증 시스템의 구축을 통하여 국내의 원격검침 서비스와 관련된 장비의 품질을 높이고, 시장의 확장을 선도하였으며, 스마트 그리드의 초창기 사업화 안착에도 많은 기여를 하였다. 또한, 전력선통신 분야 원천기술 개발의 지속 추진을 통한 각종 IPR의 확보 및 표준화 활동을 통하여 스마트 그리드 기술을 고도화하기 위해 많은 노력을 기울이고 있다. In this paper, we introduce the case study on the certificate system for Auto Meter Reading protocol, Device Language Message Specification which is a common language between metering devices and protocol with compatibility and conformance to the IEC 62056 standards. KEPCO has contributed to improve interoperability between different devices of multi vendors through the DLMS standard tests and led the smart metering industry in Korea. KEPCO has AMR system and successful business model for 550 thousands of households based on 24Mbps broadband powerline communications using its infrastructure. We have plan to continue on standardization activities stratagemically by participating in IEC working groups for the purpose of occupying the core technology of Smart Gird.

스마트그리드 AMI환경에서의 ID기반 인증기법에 관한 연구

최근 기존의 단 방향 전력망 시스템에 정보통신기술을 접목한 스마트그리드 기술의 개발이 활발하게 이루어지고 있다. 스마트그리드의 핵심 인프라로 원격검침시스템인 AMI는 스마트미터에서 측정한 전력량을 상위 데이터 저장소인 MDMS에 전송한다. 스마트미터는 정보통신기술을 활용하여 전력데이터를 전송하고 있기 때문에 기존 보안위협을 포함한 추가적인 보안위협이 예상된다. 이는 소비자의 개인정보노출 및 산업시스템 마비 등의 손실이 발생할 가능성이 있다. 따라서 본 논문은 이러한 보안위협에 대응하기 위해 스마트그리드 환경에서 스마트미터와 MDMS간 그리고 각 가정의 디바이스와 MDMS간의 상호인증과 전력량 데이터 전송방식에 관하여 제안하였다. Recently the existing one-way electricity system that combines information and communications technology to develop smart grid technology is made active. The core infrastructure of the smart grid, AMI smart meters to AMR system, the amount of power measured at the top to MDMS transmits data store. Smart meters utilizing information and communication technology to transfer data and power because of the existing security threats are expected, including the additional security threats. It exposes the privacy of consumers and industrial systems, such as paralysis is likely to result in the loss. In this paper to respond to these security threats in the environment smart grid. Also, We propose data transfer methods between smartmeter and MDMS and between home device and MDMS.

A numerical analysis of an active magnetic regenerative cascade system

Magnetic refrigeration is an emerging green technology based on the magnetocaloric effect (MCE) in solid-state refrigerants with environmentally desirable characteristics. The active magnetic regenerator is a special kind of regenerator for the active magnetic regenerative cycle (AMR), in which the magnetic material matrix works both as a refrigerating medium and as a heat regenerating medium, while the fluid flowing in the porous matrix works as a heat transfer medium. The MCE is maximal at the Curie temperature, and is large only in the temperature interval around this temperature. It is therefore advantageous that the operating point of the refrigeration plant and this temperature interval of optimal MCE coincide. Therefore a good solution is to work with a cascade system, where each unit has its own optimally adapted working temperature. In the present paper, a practical model for predicting the performance and efficiency of an AMRC (Active Magnetic Regenerative Cascade cycle) system has been developed. The model simulates both the ferromagnetic material and the entire cycle of an AMRC operating in conformity with a Brayton regenerative cycle. In addition, the model simulates a two-stage cascade systems with each stage operating at its optimal point. The program simulates a cascade system working with the Gd−x Tb1−x alloys as constituent materials for the regenerator of the first and of the second stage, varying the composition of the alloy. The heat transfer medium is a water–glycol mixture (50% by weight). With this model, the refrigeration capacity, the power consumption and consequently the coefficient of performance can be predicted. The aim of this paper is to provide some useful indications for the design of an AMR prototype. In this simulation attention is paid on both the temperature span enlargement and the compactness of the AMR system. Copyright © 2010 John Wiley & Sons, Ltd.

AMR과 DAS의 인터페이스 구현

본 논문에서는 IT 기술기반의 통신 및 컴퓨터를 이용하여 약 20-30[㎞] 떨어진 곳에 설치된 자동화 개폐기, 리클로져를 원격으로 제어, 감시, 계측하고 있는 DAS와 고압수용가의 원격검침, 요금 등의 업무를 수행하는 AMR과의 인터페이스를 구현하여 배전선로의 전체 고장 중 16[%]를 차지하는 고압수용가 구내 전기설비 고장에 의한 배전선로 파급고장에 대해 신속하고 정확하게 찾을 수 있는 방법을 제시하기 위해 DAS와 AMR의 인터페이스를 구현하는 것이다.

Experimental investigation on refrigeration performance of a reciprocating active magnetic regenerator of room temperature magnetic refrigeration

Room temperature magnetic refrigeration has been proved to be a feasible refrigerating technology and has a prosperous application potential. In this research, magnetocaloric effect (MCE) of metal gadolinium is measured and the metal is prepared from ingot to granular state by method of hydriding–ball milling–dehydriding. The other compound, Gd 5Si 2Ge 2 alloy, is also prepared into grains by mechanical comminuting and its magnetocaloric property is obtained. An experimental system of room temperature magnetic refrigeration is established, and three kinds of magnetic refrigerant (MR I: 0.3 mm mean diameter gadolinium particle, MR II: 0.55 mm mean diameter gadolinium particle and MR III: 0.3–0.75 mm Gd 5Si 2Ge 2 alloy particle) are employed in AMR. Performance experiments of AMR system under various temperature range, temperature span, flow rate, and flow period conditions are investigated. The results indicate that AMR adopting MR I, II, III can generate a maximum refrigerating capacity of 18.7 W, 17.8 W, and 10.3 W, respectively, under a 3 K temperature span. With the increasing temperature span, the capacity decreases. MR I and MR II have an equivalent refrigerating ability higher than MR III.

Urban utilities warm up to the idea of wireless automatic meter reading

While Italy's ENEL SpA heralds in the new world of automatic meter reading, the colossal utility service provider is not alone in this massive endeavour. Literally hundreds of AMR projects are being deployed worldwide from as far away as Australia and Argentina to as close as Germany and Greece. The advent of deregulation in the utility market and the technological advances in control communications has made it possible for utility service providers all over the world to take advantage of the benefits of AMR. In addition to automated meter reading, AMR systems enable load balancing and distribution, rapid identification of power faults, and remote service activation or deactivation. An AMR system can save a utility service provider million of euros per year in efficiency and maintenance fees. The key to successful wireless AMR deployment is to carefully consider the wireless technology and to put into place a long-lasting, intelligent system that meet the challenges of the residential urban metering environment by addressing interference and data reliability, and by providing long battery life.

Wireless gas [automatic meter reading

Apart from bringing automation to meter reading, AMR systems enable load balancing and distribution, rapid identification of power faults and remote service activation. An AMR system can save a utility service provider millions of dollars per year in efficiency and maintenance fees.

Automated Meter Reading a Boon for North Carolina City

This article describes how the Public Works Department of the City of Conover, North Carolina, converted their meter‐reading system to an automated system (AMR). They also replaced all 3/4 inch meters with new positive displacement meters, which would be beneficial in the continued evaluation of the new AMR system and possibly increase sales revenues by providing more accurate readings.