Merenje snage po standardu IEEE 1459-2010 upotrebom rezonatorskih filterskih struktura

Liberalizacijom tržišta električne energije merenje električne snage i energije u nesinusoidalnim uslovima dobilo je veliki značaj. Ta tema je još uvek predmet aktivnih rasprava, tako da ne postoji neka generalizovana teorija koja se može uzeti kao osnova za potrebe obračuna, evaluacije kvaliteta energije, detekcije izvora harmonika i kompenzacije u energetskim sistemima. Kao posledica, postojeći standardi se odnose na sinusoidalne slučajeve i ne daju definiciju reaktivne energije (i/ili snage) u nesinusoidalnim uslovima. Slično, oni ne daju specifične zahteve za tačnost i odgovarajuće uslove testiranja u prisustvu harmonijskih izobličenja. Jedini standard koji se odnosi na ovu problematiku je IEEE Std. 1459-2010 koji ne daje definiciju reaktivne snage u nesinusoidalnim uslovima. Koncept ovog IEEE standarda je baziran na razdvajanju snage na fundamentalni i nefundamentalni deo. Ovaj prilaz separacije na fundamentalni i harmonijski deo može se primeniti na najbitnije veličine i može se iskoristiti kao indikator kvaliteta. U radu je prikazana jedna efikasna algoritamska struktura za računanje električnih veličina definisanih standardom IEEE 1459-2010. Struktura se sastoji od dva dekuplovana dela. Za estimaciju spektra napona i struje korišćena je efikasna metoda bazirana na paralelnoj strukturi rezonantnih filtera sa zajedničkom povratnom vezom. U drugom delu strukture se na osnovu poznatog spektra naponskog i strujnog signala računaju komponente snage i indikatori kvaliteta na osnovu definicija datih u standardu IEEE 1459-2010. Predloženi algoritam je pogodan za primene u realnom vremenu. Realizacijom virtualnog instrumenta baziranog na PC računaru i programskom paketu LabVIEW, u cilju procene performansi algoritma, izvršene su računarske simulacije i eksperimentalna merenja i dati njihovi rezultati.This paper proposes an accurate and computationally efficient implementation of the IEEE Std. 1459-2010 for power measurements. An implementation is based on digital resonators embedded in a feedback loop. In the first algorithm stage, the unknown signal harmonic parameters are estimated. By this, the voltage and current signals are processed independently of each other. In the second algorithm stage, the unknown power components are estimated (calculated) based on estimated spectra. To demonstrate the performance of the developed algorithm, computer-simulated data and laboratory testing records are processed. Simple LabView implementation, based on the point-by-point processing feature, demonstrates techniques modest computation requirements and confirms that the proposed algorithm is suitable for real-time applications

Merenje komponenti električne snage po standardu IEEE 1459-2010

Merenje u nesinusoidalnim uslovima je u centru istraživanja i mnogo se napora ulaže da se pojam reaktivne snage star više od sedamdeset godina definiše na nov način. Postoji niz pristupa rešavanju problema definisanja snaga i/ili pokušaja koncipiranja merne instrumentacije za merenje snaga u sistemima naizmenične struje pod nesinusoidalnim uslovima. Jedini standard koji se odnosi na specifične zahteve za tačnost i odgovarajuće uslove testiranja u prisustvu harmonijskih izobličenja je IEEE Std. 1459-2010, koji ne daje definiciju reaktivne snage u nesinusoidalnim uslovima. Koncept ovog IEEE standarda je baziran na raz-dvajanju snage na fundamentalni i nefundamentalni deo. U literaturi su prisutne različite tehnike za imple-mentaciju standarda IEEE Std. 1459-2010. Ovaj standard je implementiran pomoću dva osnovna prilaza: (1) dvostepeni algoritam sa estimacijom harmonijskih spektara naponskog i strujnog signala u prvom koraku i računanjem nepoznatih komponenti snage u drugom koraku i (2) filterska implementacija kombinovana sa Clarke-Park transformacijom u slučaju trofaznog sistema. U radu je prikazana nova metoda za merenje električnih veličina definisanih standardom IEEE 1459-2010 koristeći drugi pristup. Ključni elementi su adaptivni pojasni i niskopropusni FIR filteri koji izdvajaju fundamentalnu i jednosmernu komponentu. U radu su korišćene tehnike oversemplinga i decimacionih filtera, čime se izbegavaju problemi vezani za osetljivost na zaokruživanje koeficijenata FIR kaskadnih filtera velikog reda, smanjuje obim numeričkih računanja i povećava tačnost merenja. Estimacija simetričnih komponenti vrši se pomoću matrice adaptivnih faznih korektora. U cilju procene performansi algoritma izvršene su računarske simulacije i dati njihovi rezultati.In this paper, the design and implementation of a novel recursive method for the power measurement ac-cording to the IEEE Standard 1459-2010 have been described. The most important parts are adaptive band and low-pass FIR filters that extract fundamental and dc components, respectively. In addition, by using oversampling techniques and decimation filters, coefficient sensitivity problems of the large-order FIR comb cascade structure are overridden and the parameter estimation accuracy is improved. The symmetrical components are estimated through a transformation matrix of adaptive phase shifters. The effectiveness of the proposed techniques is demonstrated by simulation results

Channel selector for optimization of test and callibration procedures of ICTM pressure sensors

This paper presents channel selector developed for improvement of the efficiency of the test and callibration procedure of ICTM pressure sensors. So far, this procedure allowed testing of only one sensor at the time. The channel selector enables simultaneous testing of up to five pressure sensors. This implies many benefits, such as: reduction of power consumption, reduction of the amount of gas used in the measurement system, significant saving of time needed for testing of a small series of pressure transmitters. Realization of the channel selector is based on use of a reed relay which is driven by specially designed electronics. There are two modes of operation of this device. The first one is by manual channel selection, while the second one is based on PC control realized by using dedicated software and microcontroller which are incorporated in the device itself and connected via USB communication. During the test and callibration procedure pressure is generated by MENSOR APC-600 pressure calibrator, while temperature is controlled using temperature test chamber HERAEUS VÖTSCH VMT 08/140

The implementation of 5s tools in sustainable development enterprises with small-scale production

U ovom radu analiziran je Lean alat u analizi održivog razvoja preduzeća sa maloserijskim tipom proizvodnje. Kao polazna osnova upotrebljen je 5S model. Korišćen je primer u procesu finalizacije gotovog transmitera proizvodnje IHMT-CMT-a. Takođe, alalizirani su elementi unapređenja kvaliteta procesa i primene Kaizen filozofije. Značaj rada je samokontrola/samodisciplina zaposlenih na radnom mestu. Na taj način se proces finalizacije proizvoda odvija pravovrmeno, bez otpada i gubitaka, a zaposleni stalno održavaju radno mesto uredno, čisto i funkcionalno.In this paper we analyzed the Lean tool in the analysis of sustainable development of enterprises from smallscale production. 5S model was used as a primary model. It was used for example in the process of finalizing the final transmitter IHMT-CMT production. Also, elements of quality improvement process and implementation of Kaizen philosophy were analyzed. The significance of this work is self-control/self-discipline of employees in the workplace. In this way, the finalization process of the product takes place promptly, without waste and losses, and employees continuously maintain workplace neat, clean and functional

On Multiple-Resonator-based Implementation of IEC/IEEE Standard P-Class Compliant PMUs

This article deals with the implementation of the P-Class PMU compliant with IEC/IEEE Standard 60255-118-1:2018 by usage of a multiple-resonator (MR)-based approach for harmonic analysis having been proposed recently. In previously published articles, it has been shown that a trade-off between opposite requirements is possible by shifting a measurement time stamp along the filter window. Positioning the time stamp in a proximity of the time window center assures flat-top frequency responses. In this article, through simulation tests carried out under various conditions, it is shown that requirements of the IEC/IEEE Standard 60255-118-1:2018 can be satisfied by the second and third order MR structure for particular conditions of the time stamp location

Lean Concept in Transmitter Production

The algorithm for providing improvement of production processes in the company of small-batch type of production has been intrduced in this paper. Lean manufacturing or concept in the process of improving production is used increasingly. However, the concept is designed for large enterprises. The process of production transmitters or the possibility of implementing the concept according to the known principles has been analyzed in this paper. Credibility of the algorithm is reflected in giving recommendations on how to eliminate the short comings in the production process through transmitters: regular movement of employees, regular sequence of operations, products design, and cooperation with customers, reducing inventory and control introduction in all stages of the process. The production process with the implemented process of reproduction makes an integral part of Lean concept. The paper gives an example of how to save on material and other resources in the company arising as large losses in the production process

Prototype of the multichannel acquisition system developed for ICTM pressure transmitters

This paper presents a prototype of the multichannel acquisition unit AKV-100 developed for purposes of pressure and temperature measurements using proprietary ICTM pressure transmitters TPa-110 based on MEMS piezoresistive pressure sensors and thermocouples TMMU01. Details about the acquisition unit, dedicated software, measurement setup and test procedure are given. Measurements results are presented and the directions of future research activities are discussed

Značaj modularnog dizajna proizvoda u održivom razvoju preduzeća

In this paper is shown importance of modular architecture in the sustainable development of enterprises. The application of modular design enables the development of the production program based on the results of its own development. At the illustrated example, the production of transmitters it was concluded that modular architecture enables the production of independent entities, provides the realization of products in inaccessible places, enables to precisely defined technical documentation of modules, enabling easy maintenance, repair and improvement. This paper describes an algorithm for material reuse which indicates the importance of the customer in a closed material flow. In this connection, PLC includes protection of the environment as a strategic decision in the sustainable development of enterprises.U ovom radu je prikazan značaj modularne arhitekture u održivom razvoju preduzeća. Primena modularnog dizajna omogućava razvijanje proizvodnog programa koji se bazira na rezultatima sopstvenog razvoja. Na primeru, proizvodnje transmitera konstatovano je da modularna arhitektura omogućava proizvodnju nezavisnih entiteta, omogućava realizaciju proizvoda na nepristupačnim mestima, realizuje module prema tačno definisanoj tehničkoj dokumentaciji, omogućava lako servisiranje, popravke i unapređenje. U radu je opisan algoritam za ponovnu upotrebu materijala koji ukazuje na značaj kupca u zatvorenom toku materijala. S tim u vezi, ŽCP uključuje zaštitu životne sredine kao stratešku odluku u održivom razvoju preduzeća

Analytical modelling of the transient response of thermopile-based MEMS sensors

This work presents an analytical model dedicated to study of the transient response of multipurpose MEMS devices based on thermopile sensors. In general, thermopile sensors response depends on ambient temperature, thermal conductivity of the gas inside the housing and the pressure of the gas. The presented model takes into account all these parameters. This model was sucessfully implemented for the study of transient behaviour of our multifunctional sensors with p+Si/Al thermocouples and a bulk micromachined bilayered membrane. Simulations were performed for different gases of interest and conclusions were deduced regarding the influence of relevant parameters on the thermal time constant. This analytical approach is general and flexible enough to be implemented for analysis of the transient behaviour of thermopile-based sensors when used for different applications

Flowering period of hazel cultivars and dihogamy incidence in agro-ecological conditions of continental Croatia

Istraživanja su provedena u Orahovici na tri sorte lijeske: Istarski duguljasti, Rimski i Haleški. Pojedinačno je promatrana cvatnja muških i ženskih cvjetova prema čemu je izrađen fenogram cvatnje. Cilj istraživanja je utvrđivanje fenofaza cvatnje lijeske, pojave homogamije i dihogamije te ovisnost cvatnje o klimatskim prilikama. Pokazalo se da pojava protandrije, protoginije i homogamije nije isključivo sortno svojstvo već je ovisna o sezonskim klimatskim prilikama. Na području Orahovice najčešće se pojavljuje protoginija. Protandrija se pojavljuje rjeđe i to u godinama s većom sumom srednjih dnevnih temperatura u dekadi koja prethodi cvatnji. Na osnovi izrađenog fenograma cvatnje vidljivo je da se tri odabrane sorte dobro nadopunjuju i međusobno osiguravaju dobro oprašivanje bez obzira na nepovoljne klimatske prilike koje vladaju za vrijeme cvatnje.Research was conducted on three hazel cultivars: Istarski duguljasti, Romische Zellernuss and Hallesche Riesen in Orahovica. Flowering of male and female inflorescences was observed individually according to which flowering phenogramme was completed. The aim of this research was to determine the flowering pattern of hazel, occurrence of homogamy and dichogamy and influence of weather conditions on flowering. It was observed that appearance of protandry, protogyny and homogamy is not solely varietal characteristic, but depends on seasonal climatic conditions as well. In the Orahovica area protogyny mostly occurs. Protandry occurs rarely, mainly in the years with higher sum of average daily temperatures in a decade that precedes the flowering. Based on created flowering phenogramme it is visible that all three cultivars complement each other and guarantee good pollination irrespective of possible adverse climatic conditions that can occur during flowering