Ewa Krain-Dudek, Janusz Sobota, Daniel Pawłowski, Waldemar Olech
Distribution transformers. New designs and acceptance tests in Schneider Electric Transformers Poland Sp. z o.o.
Described are present problems connected with construction and acceptance tests of distribution transformers. Discussed are new technologies and production plans of Schneider Electric Transformers Poland Sp. z o.o. in Mikołów and especially the changes applied in new constructions of distribution transformers. Presented are the produced now three-winding transformers and units filled with biodegradable and difficult to ignite fluids as well as projects concerning the construction of units equipped with on-load voltage control. Discussed are the measurement and control works, the range of performed systematically and specialized investigations as well as acceptance tests carried on by ZPBE Energopomiar-Elektryka Gliwice.
Keywords: construction of distribution transformers, acceptance tests, new technologies, Schneider Electric Transformers Poland Sp. z o.o. w Mikołowie, ZPBE Energopomiar-Elektryka Gliwice
Tadeusz Glinka, Janusz Sobota, Tomasz Mnich
Voltage regulation in transformers
Voltage regulation of a power transformer under load enables stabilisation of a power grid voltage, thereby improving its quality that is very important for electricity consumers. The energy supplier is obliged to ensure an adequate quality of the voltage for every customer regardless of the distance from the feed point.Voltage parametres have to be within the limits described by the binding regulations. Presented are here three ways to regulate transformers voltage: with tap-changers, contactors and a power electronics system. Voltage regulation with tap-changers is widely used in high power transformers. The tap-changer system was built on a 400 kVA transformer and its operational reliability is now under verification. Voltage regulation power electronics systems are under development.
Keywords: transformer, voltage regulation, tap-changer, inverter
Fire protection switch – design methodology
The function that is performed by a fire protection switch (FPS) in building objects was specified in the Regulation of the Minister for Infrastructure of 12 April 2002 on technical conditions to be met by buildings and their location. There is an ongoing debate on FPS technical solutions in which compete the views presented by professional environments of firemen and electricians. The Regulation of the Minister for Infrastructure and Construction of 17 November 2016 defined the way of declaring the performance of building products and marking them with construction mark. Despite the passage of 3 years no guidance concerning FPS design methodology has been developed – only the date limit of marking the set of products composing FPS has been prolonged until 1 January 2021.
Keywords: fire protection switch (FPS), building objects, FPS technical solutions
Zbigniew Robak, Roksana Muzyka, Małgorzata Wojtaszek
The use of products from coal tar processing to obtain anode material for Li-ion battery
The results confirming the usefulness of coal tar for obtaining the mesophase microbeads (MCMB), material for production of Li-ion battery anodes, were presented. Coal tar pitch, obtained from distillation of coal tar, that meets the specific criteria, processed thermally in specified conditions, creates anisotropic structures of mesophase that can be extracted from the isotropic mass of pitch to obtain a mesocarbon microbeads. Mesocarbon microbeads after graphitization and modification of properties are a valuable, cheap material for mass production of anodes of lithium-ion batteries. Graphitized mesocarbon microbeads used in Li-ion battery technology, in place of natural graphite, give a real possibility for significant increase of the production scale as well as for reduction of costs.
Keywords: coke-tar, coal-tar pitch, mesophase microbeads (MCMB), Li-ion batteries
Małgorzata Wojtaszek, Jarosław Zuwała, Zbigniew Robak, Roksana Muzyka
Review of the possible use of carbon materials in thermal energy storage for building construction technologies
The paper presents information on the application of carbon materials in heat energy storage technology. Phase-change materials (PCM) used in the production of heat storage systems have certain limitations in their application like thermal conductivity. Heat transport in the energy storage system based on PCM takes place by heat convection process which clearly determines the efficiency of heat storage system effectiveness. Parameters of the thermal conductivity of energy storage systems can be improved by the use of additional conductive materials. The use of a PCM-carbon composite can induce that high-performance warehouses become available in many different applications, including i.e. domestic construction. Carbon materials, of natural and synthetic origin, can be concluded as a heat conduction additive being competitive for a typical metallic conductors. Natural graphite among all the presented materials is the most optimal additive in terms of both economic and logistic approach to be a heat conductor in energy storage systems. Although, available synthetic carbon forms have better conduction parameters so that their availability and test methods are still insufficient. Among other things, for this reason, it is worth to study the possibility of using by-products or even waste materials from the electrode industry to be considered as the cheaper or/and more available heat conductors in PCM based TES systems.
Keywords: carbon materials, heat storage systems in construction industry, natural and synthetic graphite