Primjena PLC uređaja za modeliranje elektromotornog pogona

In complex industrial processes the simplification of work is ensured using complex automation solutions. In such systems it is crucial to provide as much automated tasks as possible in order to reduce possibility of human error and ensure high level of excellence for final product. Complex automation solutions require high level of excellence in design, production and commissioning. In this paper the use of PLC application for testing single part of automated system is presented. The results of testing are described in several specific steps recorded during the actual testing. This will ensure determination of errors without connection of actual electrical machine drive.Olakšavanje rada u složenim industrijskim procesima osigurava se korištenjem složenih sustava automatizacije. U takvim sustavima cilj je što više poslova odraditi automatizirano da bi se smanjila mogućnost ljudske pogreške i da bi se osigurala visoka produktivnost. Složeni sustavi automatizacije zahtijevaju visok stupanj kvalitete u projektiranju, izradi i puštanju u rad. U ovom radu prikazana je primjena PLC uređaja u ispitivanju jednog dijela automatiziranog sustava. Rezultati ispitivanja opisani su u nekoliko specifičnih koraka snimljenih tijekom ispitivanja. Na takav način omogućeno je utvrđivanje pogrešaka bez spajanja konkretnog elektromotornog pogona

Dynamical stability of the one-dimensional rigid Brownian rotator: The role of the rotator's spatial size and shape

We investigate dynamical stability of a single propeller-like shaped molecular cogwheel modelled as the fixed-axis rigid rotator. In the realistic situations, rotation of the finite-size cogwheel is subject of the envi- ronmentally-induced Brownian-motion effect that we describe by utilizing the quantum Caldeira-Leggett master equation, in the weak-coupling limit. Assuming the initially narrow (classical-like) standard deviations for the an- gle and the angular momentum of the rotator, we investigate dynamics of the first and second moments depending on the size, i.e., on the number of blades of both the free rotator as well as of the rotator in the external har- monic field. The larger the standard deviations, the less stable (i.e. less pre- dictable) rotation. We detect the absence of the simple and straightforward rules for utilizing the rotator's stability. Instead, a number of the size-related criteria appear whose combinations may provide the optimal rules for the ro- tator dynamical stability and possibly control. In the realistic situations, the quantum-mechanical corrections, albeit individually small, may effectively prove non-negligible, and also revealing subtlety of the transition from the quantum to the classical dynamics of the rotator. As to the latter, we detect a strong size-dependence of the transition to the classical dynamics beyond the quantum decoherence process.Comment: Corrections made in accordance to the Corrigendum to the published pape

Korištenje i prednosti Profinet komunikacijskog protokola u industriji

In complex industrial production processes it is necessary to introduce automation system with special consideration to process supervision. High number of automation devices in system will require great resources in quantity and speed of data transfer. The protocols such as Profibus or similar obviously will not satisfy all demands of these production processes since the high number of devices are used. The possibilities of combining standard methods of communication with industrial protocols are available by introducing the devices for supervision and eventually process management placed outside the industrial plant, such as engineers or plant manager offices, etc. One of the most popular such protocols are Profinet which uses Ethernet standard for industrial purposes, and is described in this paper.U složenim industrijskim procesima proizvodnje potrebno je ugraditi sustav automatizacije sa posebnim naglaskom na nadzor procesa. Veliki broj uređaja u automatizacijskom sustavu traži velike resurse u količini i brzini protoka podataka unutar sustava. Ukoliko se radi o velikom broju uređaja protokoli kao što su Profibus i slični očito ne mogu zadovoljiti sve potrebe takvog pogona. Uvođenje uređaja za nadzor i eventualno upravljanje pogonom u prostore koji nisu nužno vezani za samu proizvodnju, kao što su uredi inženjera, voditelja pogona, i slično, otvara se mogućnost kombinacije standardnih metoda komunikacije sa industrijskim protokolima. Jedan od najprihvaćenijih je Profinet koji koristi Ethernet standard u industrijske svrhe, i opisan je u ovom radu

Korištenje i prednosti Profibus komunikacijskog protokola u industriji

In communication standards of high and middle level it can be easy to define demands on such networks and quality of data flow. Primarily high speed of data flow is demanded, and then also demands on quality of data at the end of transmission channel. Due to such demands industrial communication in one part always follows development of communication network systems for everyday usage, but must also produce better results in terms of bad environment conditions in which the data transfer is performed. The Profibus standard was developed as a result of great project for industry and process environment. The Profibus became one of most applicable communication standards for automation systems with high complexity, and is accepted by almost all significant vendors of automation system equipment.U komunikacijskim standardima visoke i srednje razine može se vrlo jednostavno definirati zahtjeve na takve mreže i kvalitetu protoka podataka. U prvom redu traže se komunikacije na visokim brzinama prijenosa podataka, a zatim i zahtjev na kvalitetu podataka prilikom stizanja na odrediše. Zbog takvih zahtjeva industrijska komunikacija jednim svojim dijelom prati i razvoj komunikacijskih mreža koje se koriste u svakodnevnom životu, no uvijek mora garantirati bolju kvalitetu zbog lošijih uvjeta u kojima se odvija prijenos podataka. Profibus standard razvijen je kao rezultat velikog projekta upravo za industrijsku i procesnu okolinu. Njegova primjena je postala jedna od najprisutnijih u automatizacijskim sustavima veće složenosti, a prihvaćen je od strane gotovo svih značajnih proizvođača automatizacijskih sustava

Širokopojasni prijenos podataka elektroenergetskom mrežom

The paper presents an overview to broadband over powe lines. Over the past few years advances in signal processing technology have enabled the advent of modem chips that are able to overcome the transmission difficulties associated with sending communications signals over electrical power lines. There are two predominant types of BPL communications configurations: Access BPL and In-Home BPL. One of the largest commercial markets for BPL is the ability to provide Internet Services by means of the Transmission Control Protocol/Internet Protocol (TCP/IP) protocols. Another significant benefit of BPL is the ability to employ “intelligent” power line networks that make use of SCADA devices.U radu je opisan pregled širokopojasnog prijenosa podataka elektroenergetskom mrežom. Razvoj tehnologije prijenosa signala omogućio je prevladavanje problema prijenosa komunikacijskih signala putem elektroenergetske mreže. Time je omogućen širokopojasni prijenos podataka kojim se osigurava pristup Internetu koristeći postojeću infrastrukturu. Ovakva komunikacija dijeli se na: pristupnu i kućnu. Najveći ekonomski značaj ove tehnologije je mogućnost pružanja pristupa Internetu TCP/IP protokolom. Osim pristupa Internetu omogućava i implementaciju pametne elektroenergetske mreže (SCADA)

Mogućnosti korištenja European Solar Radiation Atlasa na primjeru analize dnevnog kretanja Sunca

The application of the European Solar Radiation Atlas (ESRA) in daily Sun motion in sky analysis and its effects is widely spread in all engineering professions. Mathematical relations for Sun azimuth and height in specified moment, defined by date and time, can, for instance, be used in electrical engineering calculations of energy production and control of photovoltaic plants. The results obtained at measuring stations across Europe produce empirical relations between irradiation, time and electrical energy production. In this research a model of ostensible Sun movement trough daily analysis of its height and azimuth, and the analysis of production of integrated photovoltaic plant on the roof of the Technical College in Bjelovar with the web interface implementation of ESRA model for specified application – PVGIS (Photovoltaic Geographical Information Systems) are presented.Primjena European Solar Radiation Atlasa (ESRA) u analizama dnevnih kretanja Sunca po nebu i njegovih učinaka je rasprostranjena u svim inženjerskim strukama. Matematički odnosi visine i azimuta Sunca u određenom trenutku, defniranom datumom i vremenom, mogu se npr. u elektrotehnici koristiti za proračune proizvodnje i upravljanje fotonaponskim postrojenjem. Rezultati na mjernim stanicama širom Europe daju empirijske odnose zračenja, vremena i proizvodnje električne energije. U ovom radu je dan pregled modela za prividno kretanje Sunca kroz dnevnu analizu visine i azimuta Sunca, te analiza proizvodnje fotonaponskog postrojenja na krovu zgrade Visoke tehničke škole u Bjelovaru pomoću web sučelja implementacije ESRA modela za spomenutu primjenu – PVGIS (Photovoltaic Geographical Information Systems)

Projektiranje fotonaponskih sustava za potrošače u otočnom radu

All present product suppliers use website with product data, analysis and solutions in order to gain trust from their consumers. In this paper a case study is presented where electrical energy consumption measurement system is used in order to provide design results of minimal isolated PV plant necessary for electrical energy supply system. Measured results are available on-line for registered users. This kind of history data set is sufficient to determine minimal technical demands for future PV plant. Methodology presented in this paper can also be used in design any similar electrical or other energy supply, both in isolated of grid connected operation.Danas svi dobavljači proizvoda koriste mrežne stranice s podacima o svojim proizvodima, analizama i primjerima korištenja kako bi stekli povjerenje svojih kupaca. U ovom radu prikazan je način korištenja sustava za daljinsko očitanje brojila električne energije u svrhu projektiranja minimalnih zahtjeva na fotonaponski sustav u otočnom režimu rada za pokrivanje potrebne proizvodnje električne energije za tog potrošača. Rezultati takvih mjerenja potrošnje mrežno su dostupni za svakog registriranog korisnika. Ovako dobivena baza podataka dovoljna je za određivanje minimalnih tehničkih zahtjeva na buduće fotonaponsko postrojenje. Također, metodologija prikazana u ovom radu može se primijeniti u projektiranju bilo kojeg sličnog sustava za napajanje električnom energijom, jednako u otočnom ili mrežnom radu

Mogućnosti korištenja European Solar Radiation Atlasa na primjeru analize dnevnog kretanja Sunca

The application of the European Solar Radiation Atlas (ESRA) in daily Sun motion in sky analysis and its effects is widely spread in all engineering professions. Mathematical relations for Sun azimuth and height in specified moment, defined by date and time, can, for instance, be used in electrical engineering calculations of energy production and control of photovoltaic plants. The results obtained at measuring stations across Europe produce empirical relations between irradiation, time and electrical energy production. In this research a model of ostensible Sun movement trough daily analysis of its height and azimuth, and the analysis of production of integrated photovoltaic plant on the roof of the Technical College in Bjelovar with the web interface implementation of ESRA model for specified application – PVGIS (Photovoltaic Geographical Information Systems) are presented.Primjena European Solar Radiation Atlasa (ESRA) u analizama dnevnih kretanja Sunca po nebu i njegovih učinaka je rasprostranjena u svim inženjerskim strukama. Matematički odnosi visine i azimuta Sunca u određenom trenutku, defniranom datumom i vremenom, mogu se npr. u elektrotehnici koristiti za proračune proizvodnje i upravljanje fotonaponskim postrojenjem. Rezultati na mjernim stanicama širom Europe daju empirijske odnose zračenja, vremena i proizvodnje električne energije. U ovom radu je dan pregled modela za prividno kretanje Sunca kroz dnevnu analizu visine i azimuta Sunca, te analiza proizvodnje fotonaponskog postrojenja na krovu zgrade Visoke tehničke škole u Bjelovaru pomoću web sučelja implementacije ESRA modela za spomenutu primjenu – PVGIS (Photovoltaic Geographical Information Systems)

Uloga veličine i oblika molekulskih propelera u njihovoj dinamičnoj stabilnosti u modelu kvantnog Braunovog rotatora

The subject of this doctoral dissertation research is the rotational dynamics of molecules of a specific shape, the so-called molecular propellers. The main task of the dissertation is to consider the influence of the size and shape of the mentioned molecules upon their dynamic stability. The model used is based on the application of the theory of open quantum systems and the master equations of Caldeira and Leget, as a quantum model of Brownian motion. The size of molecular propellers was introduced into the model through the dependence of the moment of inertia and the strength of the interaction with the environment on the number of blades. Dynamic stability is examined by analysis of standard deviations of the angle and momentum and by the method of quantum first time passage. The obtained results indicate a strict and complex dependence of dynamic stability on the number of blades, temperature and strength of interaction with the environment. The results also show that to achieve the desired level of dynamic stability, it is not possible to apply simple rules but a combination of different stability criteria and a procedure similar to engineering optimization is necessary

Kvaliteta određivanja osnovnih parametara električnog modela fotonaponskog modula iz nazivnih podataka

In this research the results of most commonly used mathematical model for description of electrical values in PV modules are compared to measured results. This model is usable in most of advanced systems for PV system energy production utility improvement. In order for these models to be used it is necessary to provide the correct values of model parameters. In this paper the method for determining basic parameters of serial and parallel resistances, equivalent diode and current source entirely using PV module nominal data. The results of this method are compared for with specific operating point of maximum power.U ovom istraživanju se rezultati najčešće korištenog matematičkog modela za opis stanja električnih veličina u fotonaponskim modulima uspoređuju sa rezultatima mjerenja. Korištenje ovog modela primjenjivo je u većini naprednih sustava za poboljšanje korisnosti fotonaponskih sustava. Da bi mogli koristiti model fotonaponskog modula potrebno je poznavati njegove parametre. Ovdje je prikazano određivanje osnovnih parametara serijskog i paralelnog otpora, ekvivalentne diode i strujnog izvora isključivo pomoću nazivnih podataka fotonaponskog modula. Rezultati ovog proračuna uspoređeni su sa konkretnom radnom točkom maksimalne radne snage