Noise in Electric Motors: A Comprehensive Review

Electric machines are important devices that convert electrical energy into mechanical energy and are extensively used in a wide range of applications. Recent years have seen an increase in applications where electric motors are used. The frequent use of electric motors in noise-sensitive environments increases the requirements placed on electric motors intended for these applications, especially when compared to electric motors commonly used in industrial applications. This paper provides a comprehensive review of electric motor noise. Firstly, a brief introduction to noise is given. Then, the sources of electromagnetic noise and vibration in electric machines, including mechanical, aerodynamic and electromagnetic factors, are presented. Different methods such as analytical, numerical and semi-analytical for calculating electromagnetic force, natural frequencies and noise are also analyzed. Various methods for noise reduction are presented, including skewing, stator and rotor notching and slot opening width. Finally, noise measurement standards and procedures are described.This work received financial support from the Basque Government through the Bikaintek program (Grant no. 016-B2/2021)

Uncertainties in the Testing of the Coefficient of Thermal Expansion of Overhead Conductors

Overhead lines can be replaced by high temperature low sag (HTLS) conductors in order to increase their capacity. The coe cients of thermal expansion (CTE) of the HTLS conductors are lower than the CTE of conventional conductors. The utilities and conductor manufacturers usually carry out the verification of the CTE of the overhead conductors in an actual size span. The verification is based on the observation of the change of the conductor length as a result of the conductor temperature change. This process is influenced by the coe cient of thermal expansion to be verified. However, there are other factors that also a ect it. This paper analyzes the e ect of some of the uncertainty sources in the testing of the coe cient of thermal expansion of the overhead conductors. Firstly, the thermal expansion process is described and the uncertainty sources related to the conductor and the line section are identified. Then, the uncertainty sources and their e ect on the CTE testing are quantified.This research was funded by the MINISTERIO DE ECONOMÍA, INDUSTRIA Y COMPETITIVIDAD, Spain, DPI2016-77215-R (AEI/FEDER, UE)

Sag-tension evaluation of high-temperature gap-type conductor in operation

[EN] Low-sag conductors are characterised by their ability to operate above the "knee-point temperature" (KPT). Sag-tension performance must be calculated while designing a new overhead line. The ampacity limit of the conductor is influenced by the sag and the temperature of the conductor. The maximum sag must be limited to a certain value to ensure a safe clearance between the conductor and ground. In this study, a gap-type conductor in operation was monitored to evaluate the actual KPT. The KPT in low-sag conductors is a crucial factor since it affects the sag of the conductor, which must be limited for safety reasons. The KPT was detected based on the change in the coefficient of thermal expansion value of the conductor. To perform this detection, the conductor tension and temperature were monitored. This study proposes a procedure to estimate the coefficient of thermal expansion (CTE) value. The results showed a gradual displacement in CTE. This procedure was used to perform measurements in a pilot line.This work is financially supported by the Ministerio deEconomía, Industria y Competitividad, under the project DPI2016-77215-R (AEI/FEDER, UE) and by the Universityof the Basque Country UPV/EHU (ELEKTRIKER researchgroup GIU20/034)

Photovoltaic Local Energy Communities—Design of New Energy Exchange Modalities—Case Study: Tolosa

Energy communities (ECs) can become a potential alternative to promote the fight against climate change. Technological progress and price reductions in recent years have made renewable energy-generation systems increasingly affordable and have generated economic benefits by reducing the value of electricity bills for community members, as well as reducing the growing environmental impact. In this context, the authors have taken Tolosa as a case study and conducted a technical and economic analysis of different possible structures of ECs (physical, virtual, with or without storage, participants with different types of consumption, etc.) by comparing them with each other. The generation capacity of the community and the optimal energy-management algorithms have been illustrated, from which the economic benefits for each member are extracted. A dynamic distribution factor is established as the basis of the algorithms, making the benefits fairer. The results obtained from this work, in addition to illustrating the economic benefits that each type of participant can receive, help to define the most appropriate community structure for each participant while highlighting the social and climate benefits that ECs can provide.This work is financially supported by the Basque Government under Grant IT1647-22 (ELEKTRIKER research group), and by the Ministerio de Ciencia e Innovación, the Agencia Estatal de Investigación. and the European Union under Grant TED2021-129930A-I00 funded by MCIN/AEI/10.13039/501100011033 and by the “European Union NextGenerationEU/PRTR”

A New Methodology to Manage FPGA Distributed Memory Content via Bitstream for Xilinx ZYNQ Devices

This paper proposes a methodology to access data and manage the content of distributed memories in FPGA designs through the configuration bitstream. Thanks to the methods proposed, it is possible to read and write the data content of registers without using the in/out ports of registers in a straightforward fashion. Hence, it offers the possibility of performing several operations, such as, to load, copy or compare the information stored in registers without the necessity of physical interconnections. This work includes two flows that simplify the designing process when using the proposed approach: while the first enables the protection or unprotection of writing on different partial regions through the bitstream, the second permits homogeneous instances of a design implemented in different reconfigurable regions to be obtained without losing efficiency. The approach is based and has been physically validated on the ZYNQ from Xilinx, and when using partially reconfigurable designs, it does not affect the hardware overhead nor the maximum operating frequency of the design.This work has been supported, within the fund for research groups of the Basque university system IT1440-22, by the Department of Education and, within PILAR ZE-2020/00022 and COMMUTE ZE-2021/00931 projects, by the Hazitek program, both of the Basque Government; the latter also by the Ministerio de Ciencia Innovación of Spain through the Centro para el Desarrollo Tecnológico Industrial (CDTI) within the projects IDI-20201264 and IDI-20220543, and through the Fondo Europeo de Desarrollo Regional 2014–2020 (FEDER funds)

Adaptive Static Line Rating for Systems with HTLS Conductors

Operation and planning of a power system are constrained by the rating of power lines. Usually, the static line rating is used for system operation and planning. The static line rating defined for an electric grid uses the same conservative weather assumptions for the whole grid regardless of the location of each line or its maximum-allowable conductor temperature. A separate analysis of the weather magnitudes measured in a pilot line shows how favorable air temperature and solar heating compensate for unfavorable wind speed. However, this compensation is limited for high maximum-allowable conductor temperatures. As a result, the risk of the static line rating exceeding this maximum temperature is higher for HTLS conductors. An adaptive static line rating is proposed to control the assumed risk. The wind speed assumption for the static rating is reduced for higher maximum-allowable conductor temperature.This study is financially supported by the Ministerio de Economía, Industria y Competitividad, under the project DPI2016-77215-R (AEI/FEDER, UE), and by the University of the Basque Country UPV/EHU under the project EHU16/19

Review of dynamic line rating systems for wind power integration

When a wind power system is connected to a network point there is a limit of power generation based on the characteristics of the network and the loads connected to it. Traditionally, transmission line limits are estimated conservatively assuming unfavourable weather conditions (high ambient temperature, full sun and low wind speed). However, the transmission capacity of an overhead line increases when wind speed is high, due to the cooling caused by wind in the distribution lines. Dynamic line rating (DLR) systems allow monitoring real weather conditions and calculating the real capacity of lines. Thus, when planning wind power integration, if dynamic line limits are considered instead of the conservative and static limits, estimated capacity increases. This article reviews all technologies developed for real-time monitoring during the last thirty years, as well as some case studies around the world, and brings out the benefits and technical limitations of employing dynamic line rating on overhead lines. Further, the use of these DLR systems in wind integration is reviewed.This work is financially supported by the Ministerio de Economía y Competitividad under the project DPI2013-44502-R and the Eusko Jaurlaritza under the project SAI12/103

System for ampacity monitoring and low sag overhead conductor evaluation

MELECON 2012 - 2012 16th IEEE Mediterranean Electrotechnical Conference, 25 Mar - 28 Mar 2012, TúnezAmong the different alternatives to achieve the uprating and better use of existing overhead power lines are the use of high temperature low sag conductors and the use of real time monitoring systems for knowing the ampacity of the lines. So far, the uprating of a power line through both alternatives have been considered separately. However, it is possible to combine both solutions and obtain greater benefit in terms of achievable uprating, and a better control of the reliability of the conductor. This paper presents a system for monitoring the ampacity and for the evaluation of the low sag behavior of the overhead power lines. This system allows knowing the power flow of the lines in order to optimize their use and evaluating the conductor monitored in order to validate their behavior in operating condition.This work is financially supported by the Ministerio de Ciencia e Innovación under the project DPI2009-08454, the University of the Basque Country UPV/EHU under the project EHU09/18 and the financial assistance UFI 11/28, and the Eusko Jaurlaritzako Hezkuntza, Unibertsitate eta Ikerketa Saila (Euskal unibertsitate-sistemako ikerketa-taldeak Ref. IT532-10)

Tenperatura altuko eta gezi txikiko eroaleen gezi-tenperatura erlazioa

Aireko lineen eroalea tenperatura altuko eta gezi txikiko eroale baten ordez jartzen bada, lineak eraman dezakeen potentzia elektrikoa handiagotu egiten da. Lorturiko handitzea eroalearen araberakoa da. Artikulu honetan, tenperatura altuko eta gezi txikiko eroaleen portaera mekaniko eta termikoa azaldu eta aztertuko dira. Azterketak kontuan hartzen ditu eroaleen ezaugarriak eta bere gezi-tenperatura erlazioan eragiten duten zenbait faktore: instalazio prozesuan garaturiko isurpena eta tenperatura altuko isurpena