Power quality and electromagnetic compatibility: special report, session 2

The scope of Session 2 (S2) has been defined as follows by the Session Advisory Group and the Technical Committee: Power Quality (PQ), with the more general concept of electromagnetic compatibility (EMC) and with some related safety problems in electricity distribution systems. Special focus is put on voltage continuity (supply reliability, problem of outages) and voltage quality (voltage level, flicker, unbalance, harmonics). This session will also look at electromagnetic compatibility (mains frequency to 150 kHz), electromagnetic interferences and electric and magnetic fields issues. Also addressed in this session are electrical safety and immunity concerns (lightning issues, step, touch and transferred voltages). The aim of this special report is to present a synthesis of the present concerns in PQ&EMC, based on all selected papers of session 2 and related papers from other sessions, (152 papers in total). The report is divided in the following 4 blocks: Block 1: Electric and Magnetic Fields, EMC, Earthing systems Block 2: Harmonics Block 3: Voltage Variation Block 4: Power Quality Monitoring Two Round Tables will be organised: - Power quality and EMC in the Future Grid (CIGRE/CIRED WG C4.24, RT 13) - Reliability Benchmarking - why we should do it? What should be done in future? (RT 15

International White Book on DER Protection : Review and Testing Procedures

This white book provides an insight into the issues surrounding the impact of increasing levels of DER on the generator and network protection and the resulting necessary improvements in protection testing practices. Particular focus is placed on ever increasing inverter-interfaced DER installations and the challenges of utility network integration. This white book should also serve as a starting point for specifying DER protection testing requirements and procedures. A comprehensive review of international DER protection practices, standards and recommendations is presented. This is accompanied by the identifi cation of the main performance challenges related to these protection schemes under varied network operational conditions and the nature of DER generator and interface technologies. Emphasis is placed on the importance of dynamic testing that can only be delivered through laboratory-based platforms such as real-time simulators, integrated substation automation infrastructure and fl exible, inverter-equipped testing microgrids. To this end, the combination of fl exible network operation and new DER technologies underlines the importance of utilising the laboratory testing facilities available within the DERlab Network of Excellence. This not only informs the shaping of new protection testing and network integration practices by end users but also enables the process of de-risking new DER protection technologies. In order to support the issues discussed in the white paper, a comparative case study between UK and German DER protection and scheme testing practices is presented. This also highlights the level of complexity associated with standardisation and approval mechanisms adopted by different countries

UC Berkeley's Cory Hall: Evaluation of Challenges and Potential Applications of Building-to-Grid Implementation

From September 2009 through June 2010, a team of researchers developed, installed, and tested instrumentation on the energy flows in Cory Hall on the UC Berkeley campus to create a Building-to-Grid testbed. The UC Berkeley team was headed by Professor David Culler, and assisted by members from EnerNex, Lawrence Berkeley National Laboratory, California State University Sacramento, and the California Institute for Energy & Environment. While the Berkeley team mapped the load tree of the building, EnerNex researched types of meters, submeters, monitors, and sensors to be used (Task 1). Next the UC Berkeley team analyzed building needs and designed the network of metering components and data storage/visualization software (Task 2). After meeting with vendors in January, the UCB team procured and installed the components starting in late March (Task 3). Next, the UCB team tested and demonstrated the system (Task 4). Meanwhile, the CSUS team documented the methodology and steps necessary to implement a testbed (Task 5) and Harold Galicer developed a roadmap for the CSUS Smart Grid Center with results from the testbed (Task 5a) and evaluated the Cory Hall implementation process (Task 5b). The CSUS team also worked with local utilities to develop an approach to the energy information communication link between buildings and the utility (Task 6). The UC Berkeley team then prepared a roadmap to outline necessary technology development for Building-to-Grid, and presented the results of the project in early July (Task 7). Finally, CIEE evaluated the implementation, noting challenges and potential applications of Building-to-Grid (Task 8). These deliverables are available at the i4Energy site: http://i4energy.org/

3D Signal Strength Mapping of 2.4GHz WiFi Networks

Many commercial businesses operate out of multi-story office buildings. These companies often use many Wi-Fi access points to set up their own wireless network. IT personnel determine proper Wi-Fi access point placement using Wi-Fi strength maps. Conventional Wi-Fi strength maps only provide a two-dimensional view representing the wireless access point\u27s effective range. The signal quality and strength measurements do not include changing vertical elevation. Efficient network layout in a multi-story building requires a system calculating signal quality metrics in three dimensions. This project involves designing and prototyping a system to achieve 2.4GHz Wi-Fi signal quality measurements in a three-dimensional reference plane. The instrument continuously monitors its location and the 2.4GHz Wi-Fi network’s received signal strength. The user generates a 3D model of the 2.4GHz Wi-Fi network coverage using the collected signal metrics

Network Infrastructure Essentials Course Development

Voice and data cabling enable people around the world to communicate by phone, fax, and computer. Cabling is the basis for virtually every network. Today\u27s voice and data cabling is engineered to balance high performance with cost efficiency. The quality of the service provided by the cabling is directly related to the quality of the installation. Properly installed cabling can provide years of service for networks, in most cases outlasting every device connected to the network. Experience has taught us that too many people don\u27t realize the importance of cable infrastructure. At Alfred State College, in the Computer Engineering Technology curriculum there is not a course specifically targeted at the cable infrastructure. This project was to develop a new course aimed at the cable infrastructure to be implemented into the curriculum. This paper is about the entire course development process from project inception to course implementation. Although this project was to design a network infrastructure course, the process used could be applied to develop a new course for any curriculum

IoT-teknologian hyödyntäminen sähköverkko-omaisuuden hallinnassa

Objective of this thesis is to define and assess changes in energy sector, which will directly or indirectly affect distribution grid operation and management in Finland, and to determine measurable events or variables, which enable identification and monitoring of the recognized changes. Based on assessment of the upcoming changes, possibilities for utilizing IoT technologies in management and monitoring applications of the identified changes, are assessed. In the assessment of upcoming changes, total of eight subjects were covered and microgeneration, electric vehicles and heat pumps were identified to be the most probable changes to realistically penetrate Finnish energy sector within a time scope of approximately 10 years. However, none of the assessed, changes, were found to have significant and wide-scale effects in terms of performance of Finnish distribution networks. For utilization of IoT technologies in distribution networks one application for operational grid monitoring of power quality problems derived from residential photovoltaic generation, and three cases for IoT based asset health and condition monitoring were assessed. Furthermore, requirements and architecture for data storage and analysis platform of IoT based system were discussed. From the evaluated applications condition monitoring scheme of circuit breakers was determined to be the most promising alternative.Diplomityön tavoitteena on määritellä ja arvioida energiasektoriin vaikuttavien tulevien muutosten suoria tai epäsuoria vaikutuksia jakeluverkon toimintaan ja hallintaan. Havaittujen muutosten vaikutuksista on tarkoitus tunnistaa mitattavia ilmiöitä tai suureita, jotka mahdollistavat muutosten tunnistamisen sekä seurannan. Muutosanalyysiin pohjautuen tavoitteena on tunnistaa ja arvioida mahdollisuuksia IoT-teknologian hyödyntämiseksi havaittujen muutosten aiheuttamien ongelmakohtien tai mahdollisuuksien tunnistamisessa, seurannassa sekä hallinnassa. Energiasektoriin vaikuttavien muutosten analyysissä arvoitiin kokonaisuudessaan kahdeksaa eri aihealuetta ja lopputuloksena pientuotannon, sähköautojen sekä lämpöpumppujen todettiin olevan todennäköisimmät teknologiat, jotka yleistyvät merkittävissä määrin suomalaisessa sähköverkossa seuraavan kymmenen vuoden aikana. Minkään käsitellyn muutoskohdan ei kuitenkaan todettu aiheuttavan laajamittaisia ja merkittäviä ongelmia jakeluverkon toimintaan. IoT-teknologian hyödyntämiseen jakeluverkkotoiminnassa käsiteltiin yhtä verkon käyttöön ja sähkön laatuun liittyvää sovellusta, jonka avulla hajautetun pienaurinkotuotannon vaikutuksia pystytään seuraamaan, sekä lisäksi kolmeen eri verkkokomponenttiin kohdistuvaa jatkuvan kunnon seurannan sovellusta. Tämän lisäksi IoT-järjestelmän toteuttamiseksi vaadittavalle analyysi- ja tietojärjestelmäalustalle määriteltiin rakenteellisia ja toiminnallisia tarpeita. Työssä käsitellyistä IoT-sovelluksista lupaavimmaksi todettiin katkaisijoihin kohdistuva jatkuvan kunnonhallinnan sovellus

Communications

The communications sector of an economy comprises a range of technologies, physical media, and institutions/rules that facilitate the storage of information through means other than a society\u27s oral tradition and the transmission of that information over distances beyond the normal reach of human conversation. This chapter provides data on the historical evolution of a disparate range of industries and institutions contributing to the movement and storage of information in the United States over the past two centuries. These include the U.S. Postal Service, the newspaper industry, book publishing, the telegraph, wired and cellular telephone service, radio and television, and the Internet

Overcoming obstacles to electrification in Congo (DRC)

Includes bibliographical references.The contrast between the very low rate of electricity access (about 6% of households) and the significant energy resources existing in Congo justified an investigation into the obstacles to electrification and ways to overcome them. Basically electricity is generated from hydroelectric plants; the most important located in the western tip of the country (including Inga I and Inga II) and in the copper mining area in the southeast. Only the copper mining area, the area around the capital city Kinshasa and some other towns are connected to the grid or to isolated hydro plants, leaving vast parts of the country unserved. Description and analysis of existing electricity systems, their current problems and the sector master plans led to the identification of the following major obstacles to electricity expansion: [* Poor and declining performance of the electricity sector in terms of plant availability, overall losses, non-payment, and poor collection; depriving the national utility of the necessary capacity and resources to undertake electrification. * High cost of expansion programs under the approach of extending networks by transmission and three-phase distribution lines in a vast country. Limited electricity demands in most areas, lack of standardization of voltages and network equipment, and high standards of connection equipment also contributed to increase electrification costs.] A review of literature showed that, where already applied, the recommendation of international organisations to restructure and ultimately privatise electricity utilities has yielded limited results on the particular issue of electricity expansion towards low-load areas. As electrification of such areas is a major objective in Congo, this justifies that we do not recommend this route as a key strategy in solving the electrification problem in Congo. In other words the objective of expanding electricity throughout the country is not likely to be met by private operators that prefer large-scale electricity production for urban and industrial markets and emphasize the profitability of every project. However possible ways to improve utility's performance were identified in the literature. These include: the use of prepaid meters to improve collection, transferring the management of distribution networks in some areas to local organisations, attribution of more authority to the utility to enforce non-payment and staff training under a more experienced utility in the field. The liberalization of small-scale production that allows small operators such as missionaries, NGOs, or agro-processing industries to generate and possibly distribute electricity in remote areas may also contribute to expanding electricity in the country. The literature review also revealed that alternative MV distribution technologies and connection practices tested and successfully applied in other countries for low-cost electrification were available. Despite minor inconveniences such as their capacity restriction, and the inability to provide three-phase power for motors, single-phase technologies result in cost-effective networks as far as rural electrification is concerned. This is attractive for rural electrification in Congo. Applying single-phase MV technologies with adapted SASS and PIESA guidelines and standards to the design of an isolated rural network in eastern Congo, the following results were obtained: • When loads to be served are small (about 100-200kVA) phase-phase and SWER lines are cheaper to build than three-phase lines. As loads encountered in most rural areas in Congo are generally smaller than 100kVA and can reach 100-200kVA in the medium or long run, single-phase networks can adequately supply these areas from existing networks or from local plants. • The low cost of these networks in rural areas is a result of using a reduced number of components (conductors, poles, insulators and pole-top hardware), conductors of small size and of higher ratio strength to weight (T/wc), such as ACSR, that result in long spanning lengths. • If three-phase systems were systematically used, the cost of individual connection would be higher and the capacity in the networks would have been much greater than needed. Besides, given the limited financial resources other communities could not be connected owing to the high cost of three-phase lines to connect them. In addition, in order to reach the viability of the electrification project a higher tariff should be used. This is the main finding of the financial analysis carried out to investigate the viability of the electrification project in eastern Congo. As a result of high connection costs and tariffs, electricity would become unaffordable to most rural customers. This contradicts the primary objective of providing electricity to most possible customers. In practice, as shown by the case study, the pattern of electrification should be as follows. From existing networks with sufficient capacity or from a nearby plant, an optimised three-phase line towards a main center is built. Single-phase feeders of adequate rating (taking into account present demands and future growth) derive from the backbone towards various load centers. This pattern can be applied to most rural areas in Congo. At the customer level, ready boards that include isolators, protection, sockets, switches and possibly lights are installed. The cost reduction at the network and at the customer level should result in more affordable connection costs for customers. In addition to the introduction of lower cost technologies, planning approaches should be adapted. The extent to which electricity contributes to socio economic development should be the main consideration in planning electricity expansion. In other words emphasis should be put on economic and socio economic electrification. The productive uses of electricity in economic and socio economic projects bring sustainability and may attract funding for other projects from development organisations. However some social electrification to gain political support for the economic and socio economic projects are necessary. The traditional planning policy that justifies building three-phase lines as a precaution to avoid costlier upgrading at a later stage, is not adequate when financial resources and plant capacity are limited and when uncertainty exists about load growth. In other words, three-phase networks, with capacity high enough to meet years of demand that can sometimes not grow as expected, deprive other customers of connections while capacity is idle in the existing tri-phase networks. The study has shown that there is substantial scope for the application of lower cost distribution technologies than the present standards in Congo. Applying low-cost electrification technologies such as single-phase MV distribution systems to expand electricity from existing networks and from small-scale hydro plants (as a measure to postpone the construction of more costly transmission lines), after the utility has improved its performance and skills, should significantly contribute to expand electricity in Congo. In this process, utility's efforts can be shared and complemented by small operators such as missions, NGOs, and agro-processing companies in isolated areas and at small-scale level