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eng New developments in dry-type technology
Köseoğlu, Ahmet Kerem
Transformers Magazine Vol. 8, No. SE2, 2021
Today, dry-type transformers ratings could go up to 63 MVA, and voltage levels of 145 kV are achieved. This article will share some new trends in dry-type transformers and some challenges that technology faces. Technology is developed with new demands of the market, and manufacturers are racing with each other to find optimization points for both manufacturing and design. Dry-type technology is mostly quartzfilled, or glass-fibre reinforced, but recently, VPI became a popular solution for some specific applications. The size of the transformer...
Hrčak ID: 267208

eng Corrosion protection of core steel in dry-type transformers - Anticorrosion coating: some dos and don’ts
Sakr, Aiman
Transformers Magazine Vol. 7, No. 1, 2020
This article demonstrates how corrosion of core steel starts, presents its negative effect on transformer's efficiency, talks about the types of coating used on core steel material as well as the methods used in applying those layers of coating. It also provides a collection of data and best practices useful to identify the proper method for anticorrosion painting of the stacked iron core in dry type distribution transformers including the difficulties that may be encountered during this operation and the measures to be taken to eliminate the m...
Hrčak ID: 232088

eng The pluggable transformer: flexibility for future grids
Mertens, Carmen; Grund, Ruben; Spaeth, Christian
Transformers Magazine Vol. 3, No. 4, 2016
Transformers are becoming more and more space-saving, but they also need to be flexible, perhaps even mobile. All components must offer highest operational reliability, allowing quick installation as well as long-term flexibility. This is the reason why separable connecting systems are the next step in connecting transformers. As they are making progress toward replacing conventional connection methods, the importance of an entire pluggable product portfolio is increasing. This portfolio includes pluggable surge arresters as they are a vital co...
Hrčak ID: 167113

eng FEM-based Modeling and Optimization of Dry-Type Transformers with Metaheuristic Algorithms
Kul, Seda; Tezcan, Suleyman Sungur; Duysak, Huseyin; Celtek, Seyit Alperen
Tehnički vjesnik Vol. 29, No. 5, 2022
Transformer optimization is a programming problem with an objective function for calculating the characteristics of a transformer in detail according to user requirements. Especially in recent years, efficient and optimum design of the transformer has become increasingly important. This study presents a comparative analysis of the application of metaheuristic optimization algorithms in transformer design for maximum efficiency of a three-phase dry-type transformer. In addition, transformer modeling was done using FEM analysis, and its magnetic...
Hrčak ID: 281684

eng A dry type HV insulation system for extreme environments
Middleton, Robert; Euvrard, Eric
Transformers Magazine Vol. 6, No. 2, 2019
The aim of this article is to make readers aware of a dry type, paperless insulation technology that offers a safer and cost-effective alternative to traditional oil-filled current transformers. The design concepts and advantages of this unique HV dry type current transformer technology have been delivering verifiable improvements to the power grid over the past 20 years from 35 kV to 600 kV. The example of the implementation of this technology in Canada is a good case in point. Multiple evolutions of the technology have been continuously expan...
Hrčak ID: 218841

eng Distribution transformers market
Saeed, Saqib; Sheppard, Shirin
Transformers Magazine Vol. 6, No. 5, 2019
Global distribution transformers market reached around $5.5 billion in 2018 (up to 600 kVA and below 40 kV). The majority of this demand, around 74 %, came from distribution utilities globally, followed by 19 % from industry and around 7 % from power generation. As a general trend, market in emerging countries is mostly driven by new additions along with replacements, while in developed markets, including western Europe and North America, most of the demand is due to end-of-life replacements. Distributed generation and electric vehicle supply i...
Hrčak ID: 228364

eng The circularity of medium-power electrical transformers
De Wachter, Bruno; Jezdinsky, Tomas
Transformers Magazine Vol. 9, No. 1, 2022
The Design-for-recycling of mediumpower transformers is complicated by their long lifetimes. What will the recycling markets and technologies look like 50 years from now? We must be content with basing longterm predictions on the presentday situation. The Copper Alliance conducted an in-depth survey of the current state of transformer recycling. With their high metal content and straightforward disassembly, liquidfilled transformers score highly in terms of circularity. This can be further enhanced by using copper for transformers are a differ...
Hrčak ID: 270808

hrv Kavitacija u centrifugalnim crpkama
eng Cavitation in centrifugal pumps
Vuković, Živko; Halkijević, Ivan
Građevinar Vol. 63, No. 01., 2011
Dan je pregled aktualnih znanstvenih istraživanja fenomena kavitacije kod centrifugalnih crpki suhe izvedbe. Kao temeljni parametar pri opisu pojave i razvoja kavitacije rabljena je koncepcija raspoložive i potrebne neto pozitivne usisne visine. Iznesene su spoznaje kojima se osigurava beskavitacijski rad crpki, čime se otklanja mogućnost pojavljivanja u praksi značajnih problema pri redovitom pogonu i održavanju. Na primjeru je prikazan proračun neto pozitivne usisne visine.
Hrčak ID: 64219