Protection Coordination and Anti Islanding Protection Solution for Biomass Power Plant Connected on Distribution Network

Protection coordination as well as anti-island protection play significant role in the process of biomass power plant connection on the distribution network. Distribution generation island operation in Croatia is unacceptable according to the existing National grid code Paper presents a protection coordination of all passive protections used in the real biomass power plant and connected distriubution network feeder. Short-circuits three phase, two phase and single line to ground faults and generator islanding simulations have been performed and simulated in the time domain at the different network  locations using DIgSILENT Power Factory software. The time-current plots coordination of protective devices are made using Smart PDC module in Easy Power Protector software tool

MRI reconstruction using Markov random field and total variation as composite prior

Reconstruction of magnetic resonance images (MRI) benefits from incorporating a priori knowledge about statistical dependencies among the representation coefficients. Recent results demonstrate that modeling intraband dependencies with Markov Random Field (MRF) models enable superior reconstructions compared to inter-scale models. In this paper, we develop a novel reconstruction method, which includes a composite prior based on an MRF model and Total Variation (TV). We use an anisotropic MRF model and propose an original data-driven method for the adaptive estimation of its parameters. From a Bayesian perspective, we define a new position-dependent type of regularization and derive a compact reconstruction algorithm with a novel soft-thresholding rule. Experimental results show the effectiveness of this method compared to the state of the art in the field

Cost-benefit comparison of on-grid photovoltaic systems in Pannonian parts of Croatia and Serbia

Rad predstavlja detaljnu analizu potencijala sunčeve energije i analizu isplativosti instaliranja fotonaponskih sustava u Panonskim dijelovima Hrvatske i Srbije. Uspoređeni su tarifni sustavi za poticanje proizvodnje iz električne energije pomoću mrežnih fotonaponskih sustava i time rezultirajućom dobiti s jedne strane s trenutnim investicijskim i pretpostavljenim troškovima održavanja i pogona tijekom životnog vijeka s druge strane. PVGIS – PhotoVoltaic Geographical Information System korišten je za podatke o sunčevom zračenju i proračunu očekivane proizvodnje električne energije iz fotonaponskih sustava nazivne snage do 10 kW, 30 kW, 300 kW i preko 300 kW (prema različitim poticajnim tarifama u Hrvatskoj) Rezultati pokazuju značajne razlike u razvoju fotonaponskog tržišta u Hrvatskoj i Srbiji i potrebu daljnjeg poboljšanja sustava poticaja i legislative u Srbiji kako bi se instaliranje fotonaponskih sustava učinilo izvodivim.The paper presents detailed comparison of solar energy potentials and cost-benefit analysis of installing photovoltaic power systems in Pannonian parts of Croatia and Serbia. Feed-in tariff systems for incitement of the electricity production from on-grid photovoltaic power systems and the resulting benefits on one side and the current investment and the projected life-time operation and maintenance cost on the other side, have been compared. PVGIS – PhotoVoltaic Geographical Information System have been used for data on solar irradiation and calculation of expected electricity production from PV systems with rated power up to 10 kW, 30 kW, 300 kW and over 300 kW (according to the different feed-in tariffs in Croatia). The results indicate substantial differences in PV markets development in Croatia and Serbia and the necessity to improve feed-in tariffs and legislation in Serbia in order to make the installation of PV systems feasible

Improving the Conditions in a Radial Distribution Feeder by Implementing Distributed Generation

Distribution feeder is the final stage in the delivery of electricity to consumers. The feeder can be radial or networked. Radial feeders leave the power station towards the consumers without any connection to other power supply. Networked feeders have multiple connections to other supply points. It is common for long radial feeders for voltage to drop along the way and for losses to increase with increasing consumer’s power or the number of consumers. In order to minimize feeder losses and improve voltage profile distributed generation (DG) can be implemented. It is important to define the optimal location and power of distributed generation in a specific feeder to obtain its maximum potential benefits. This paper presents a solution for optimal DG placement by selecting the right terminal and power of DG using the Genetic Algorithm (GA) and the Artificial Neural Network (ANN) hybrid method. The method is tested on a part of Croatian distribution network and verified by DIgSILENT PowerFactory software and the analytical approach. The results and comparison thereof and presented in clear and legible form

The Applications of Blockchain Technologies to Electricity Markets

This paper is a summary of the CIGRE Technical Brochure 824 The Role of Blockchain Technologies in Power Markets [17]. The work of the contributors to the Technical Brochure is recognised. It is proposed to follow up this work in a new working group with a more in-depth look at the potential applications for blockchain in the area of energy trading

Solar Energy Potential in Pannonian Part of Serbia and Croatia

Renewable energy sources have their share in the energy balance of almost every country, but not as much as they should compared to the given energy potential, although they allow the application of clean technologies and pollution reduction, reduce energy dependence on fossil fuel markets and enable the development of new technologies and supporting infrastructure that create new jobs. The primary interest of society as a whole is a rational energy use. With increasing population and growing demands for energy production and consumption, as well as the fact of the limited fossil fuel resources whose utilization leads to environmental pollution (the emergence of the greenhouse effect and global warming) there is an interest in increasing the participation of renewable energy sources (RES ) in energy sector. The total potential of RES in Vojvodina Province is 1293 ktoe/a, 34 ktoe/a of which (i.e. 2.6% of the total potential) lies in solar energy utilization. Possible thermal energy production from RES in Vojvodina Province is around 44.890 TJ/a, where 1400 TJ/a can be obtained from solar energy. Possible electricity production from RES in Vojvodina Province is around 2266 GWh/a, and solar energy has no participation in this production according to the Energy balance of Vojvodina Province. Total possible energy production from RES in Croatia is estimated to 1046 ktoe/a in 2010, 12 ktoe/a of which (i.e. 1.2% of total possible potential) with expected growth to 2112 ktoe/a in 2020, 126 ktoe/a of which (i.e. 6.0% of total possible potential) and around 3502 ktoe/a in 2030, 331 ktoe/a of which (i.e. 9.4% of total possible potential). Due to the incentive scheme for RES electricity production in Croatia, this market is growing rapidly and the expected installed electrical RES capacities in Croatia in 2030 are 3055 MW mainly in wind power plants (2000 MW) due to the limited wind potentials mainly not located in Slavonia. Although there are no local data available in Slavonia, we can expect at least 50% of biomass and biogas power plants planned capacities in Croatia and around 20% of waste, geothermal and photovoltaic power plants summing up to over 1850 GWh/a with minimal participation of solar energy of not more than 3%. A share of RES in the energy balance of the country has its own energy, socio-economic and environmental benefits. RES provides application development and deployment of new technologies and supporting infrastructure, and therefore enables possibilities for new jobs, which directly contributes to economic development at local, regional and national level

Solar Energy Potential in Pannonian Part of Serbia and Croatia

Renewable energy sources have their share in the energy balance of almost every country, but not as much as they should compared to the given energy potential, although they allow the application of clean technologies and pollution reduction, reduce energy dependence on fossil fuel markets and enable the development of new technologies and supporting infrastructure that create new jobs. The primary interest of society as a whole is a rational energy use. With increasing population and growing demands for energy production and consumption, as well as the fact of the limited fossil fuel resources whose utilization leads to environmental pollution (the emergence of the greenhouse effect and global warming) there is an interest in increasing the participation of renewable energy sources (RES ) in energy sector. The total potential of RES in Vojvodina Province is 1293 ktoe/a, 34 ktoe/a of which (i.e. 2.6% of the total potential) lies in solar energy utilization. Possible thermal energy production from RES in Vojvodina Province is around 44.890 TJ/a, where 1400 TJ/a can be obtained from solar energy. Possible electricity production from RES in Vojvodina Province is around 2266 GWh/a, and solar energy has no participation in this production according to the Energy balance of Vojvodina Province. Total possible energy production from RES in Croatia is estimated to 1046 ktoe/a in 2010, 12 ktoe/a of which (i.e. 1.2% of total possible potential) with expected growth to 2112 ktoe/a in 2020, 126 ktoe/a of which (i.e. 6.0% of total possible potential) and around 3502 ktoe/a in 2030, 331 ktoe/a of which (i.e. 9.4% of total possible potential). Due to the incentive scheme for RES electricity production in Croatia, this market is growing rapidly and the expected installed electrical RES capacities in Croatia in 2030 are 3055 MW mainly in wind power plants (2000 MW) due to the limited wind potentials mainly not located in Slavonia. Although there are no local data available in Slavonia, we can expect at least 50% of biomass and biogas power plants planned capacities in Croatia and around 20% of waste, geothermal and photovoltaic power plants summing up to over 1850 GWh/a with minimal participation of solar energy of not more than 3%. A share of RES in the energy balance of the country has its own energy, socio-economic and environmental benefits. RES provides application development and deployment of new technologies and supporting infrastructure, and therefore enables possibilities for new jobs, which directly contributes to economic development at local, regional and national level

Ponovno izrisovanje meja: transformacije identitet in redefiniranje kulturnih regij v novih političnih okoliščinah

Zbornik Ponovno iscrtavanje granica: transformacije identiteta i redefiniranje kulturnih regija u novim političkim okolnostima izrastao je iz znanstveno-stručnog skupa 12. hrvatsko-slovenske etnološke paralele, održanog 23. – 25. rujna 2012. godine u Dugoj Resi. Hrvatsko-slovenske etnološke paralele oblik su regionalne suradnje koji kroz susret i predavanja etnologa iz Hrvatske i Slovenije tematizira regionalne znanstvene i kulturne veze i interkulturni dijalog u međunarodnom okružju. Riječ je o događanju koje ima kontinuitet od 1981. godine a kojemu su cilj nove znanstvene spoznaje i ujedno problematizacija i valorizacija značenja općepoznatih činjenica iz i o tradicijskoj i suvremenoj kulturi u regiji. Ovaj zbornik, kao proizvod regionalne znanstvene suradnje, propituje (re)definiranje kulturnih regija i transformacije kulturnog identiteta u novim političkim okolnostima (završetak pristupnih pregovora s EU i članstvo u EU). Jedno od temeljnih pitanja s kojim se bave pojedini autori u zborniku odnosi se na koncepcije vezanih uz (re-/de-) kreiranje kulturnih regija i granica u tradiciji i u suvremenosti. Tu se propituju politike, prakse i uloge koje koncepti o pojedinim europskim regijama i područjima („srednja Europa“, „jugoistočna Europa“, „Balkan“, „Mediteran“ i dr.) imaju u stvaranju predodžbi o sebi i drugima. Nadalje, autore zanima kako se podržava interkulturni dijalog unutar regija i preko njih. Pritom propituju kulturno uvjetovane prakse i predodžbe putem kojih se uspostavljaju, nadilaze ili brišu kulturne i političke granice i ujedno putem kojih se podržava interkulturni dijalog ili konflikt. Važno je pitanje i kako različiti markeri kulturnog identiteta potvrđuju ili raslojavaju simboličke granice. Tu je naglasak na analizi različitih markera identiteta kojima se potvrđuju ili raslojavaju simboličke granice te na procesima identifikacije na različitim razinama. Konačno, propituje se i mijena kulturnih fenomena u kontekstu “europeizacije” kulture. Radovi okupljeni u ovom zborniku ujedno osvjetljavaju promjene etnološkog predmeta bavljenja i nove etnološke izazove uslijed novih političkih okolnosti

Brašno - Kruh '15

Proceedings contains 28 original research articles presented at 8th International Congress Flour – Bread ’15 and 10th Croatian Congress of Cereal Technologists Brašno – Kruh ’1

Planning of Distributed Generation Optimal Operation using Hybrid Method

U doktorskom radu predstavljen je algoritam kratkoročnog planiranja pogona distribuiranih izvora koji ima za cilj smanjenje tehničkih gubitaka radne snage u aktivnoj distributivnoj mreži. Predloženi algoritam se sastoji od tri cjeline realizirane metodama računalne inteligencije: predviđanja proizvodnje sunčanih elektrana, planiranja optimalnog pogona hibridnih distribuiranih izvora i ocjenjivanja optimizacijskih rješenja. Predviđanje proizvodnje sunčanih elektrana realizirano je modeliranjem višeslojne umjetne neuronske mreže koja temeljem ulaznih podataka o temperaturi zraka, intenzitetu sunčevog zračenja, relativnoj vlažnosti zraka i brzini vjetra pruža podataka o očekivanoj proizvodnji sunčane elektrane. Planiranje optimalnog pogona najsloženiji je dio predloženog algoritma jer podrazumijeva jedinstvenu hibridnu optimizacijsku metodu zasnivanu na inteligenciji roja čestica uz uvažavanje načela elitizma iz genetskog algoritma. Sa optimizacijskom metodom hibridiziran je simulacijski paket MATPOWER koji se koristi za modeliranje ispitnih elektroenergetskih sustava, proračune tokova snaga i tehničko određivanje distribuirane proizvodnje prema parametrima čestica optimizacijske metode. Ocjenjivanje optimizacijskih rješenja treća je cjelina predloženog algoritma, realizirana sustavom neizrazite logike, a pruža ocjenu troškovne učinkovitosti planiranog pogona distribuiranih izvora s obzirom na uštede postignute smanjenjem gubitaka radne snage. Predloženi algoritam kratkoročnog planiranja uspješno je primijenjen u postupcima optimizacije i planiranja pogona distribuiranih izvora na tri ispitna elektroenergetska sustava te potpunu primjenjivost dokazuje visokom razinom učinkovitosti optimizacije aktivnih radijalnih i prstenasto-povezanih elektroenergetskih mreža.The doctoral thesis presents an algorithm for distributed generation short-term planning aimed at reducing the active power technical losses in the distribution network. The proposed algorithm consists of three parts: prediction of solar power plants energy production, optimal operation planning of multiple hybrid distributed generation units, and evaluation of optimization results. Prediction of solar power plants energy production is achieved by modelling multilayer artificial neural network capable of providing the information on expected solar power generation based on input data on air temperature, solar irradiation, relative air humidity, and wind speed. Optimal operation planning of distributed generation is the most complex part of the proposed algorithm because it implies a unique hybrid optimization method based on particle swarm optimization with respect to the elitism principle of the genetic algorithm. The MATPOWER simulation package, which is used for test power systems modelling, power flow calculations, and the technical determination of distributed generation according to the particle parameters, has been hybridized within the optimization method. Evaluation of optimal solutions is a third part of the proposed algorithm, achieved by fuzzy logic system, which provides the evaluation of cost efficiency for the planned operation of distributed generation with respect to savings achieved by active power losses reduction. The proposed short-term planning algorithm has been successfully applied in the optimization and planning of distributed generation in three test power systems, and full applicability is proved by a high level of optimization efficiency of active radial and meshed power networks