Avtomatizacija meritve U-I karakteristike varistorja

Rus, Tomaž (author), Beguš, Samo (mentor)

V pričujočem delu je predstavljena posodobitev merilnega mesta in programiranje aplikacije za avtomatizacijo meritev U-I karakteristike varistorja. Posodobljeno merilno mesto vključuje osebni računalnik in inštrument, ki je povezan nanj, ter nadomešča stari, analogni inštrument, kateri ni imel možnosti povezave z računalnikom. Projekt se je začel zaradi zahtev kupcev po bolj točnih in računalniško obdelanih meritvah in merilnih rezultatih ter zaradi boljše sledljivosti in analize preteklih rezultatov. Za programiranje aplikacije sem uporabil programsko opremo National Instruments Labview, za izvedbo meritev pa inštrument Keithley 2410 SourceMeter, ki je priključen na osebni računalnik in v celoti voden preko napisane aplikacije. V delu je opisan varistor, opis obstoječega merilnega sistema, predstavljen je novi merilni sistem, na kratko je opisana primerjava podatkovnega vodila po standardu RS-232 in IEEE-488 vodila (GPIB, General Purpose Interface Bus), načrtovanje programa, zahteve, programiranje in opis programa, potek izvedbe meritve, rešitve problemov in zaključek z možnimi posodobitvami. V poglavju o varistorju je opisana osnovna naloga varistorjev, različne izvedbe le teh in karakteristike. Poglavje o obstoječem merilnem sistemu vsebuje stari merilni postopek in razloge za zamenjavo z novejšim sistemom. Omenjene so tudi druge možnosti glede implementacije merilnega mesta in obrazloženo je, zakaj je izbrana rešitev najbolj optimalna izbira. Opis novega sistema je samostojno poglavje, v katerem je opisan merilni postopek, podatkovne povezave med računalnikom in inštrumentom in razlogi za izbiro le teh. Opis delovanja programa nam pove, kako je program sestavljen ter kakšni ukazi so potrebni za komunikacijo z inštrumentom. Načrtovanje, potek in zahteve za program so opisane v poglavju Potek načrtovanja in programiranja. Opisani so tudi primeri neuresničenih zahtev in obrazloženo je, zakaj je temu tako. V poglavju o programiranju teče beseda o programskem okolju Labview, komponentah in dodatnih programskih paketih, ki sem jih uporabil pri programiranju. V opisu programa je razloženo, kakšne metode so uporabljene za najboljši prikaz merilnih rezultatov, ter kakšna je struktura programskega projekta. Potek testiranja elementa zahteva svoje poglavje in opisuje vse številke in kode, ki se prenesejo iz podatkovne baze, ki so potrebne za izvedbo meritve in za obdelavo rezultatov. Opisani so stresni testi za varistorje, primerjava karakteristik in izračuni koeficientov. Pri programiranju sem naletel na težave. Rešitve težav so opisane v poglavju rešitve problemov. V poglavju, kjer je opisano izvajanje programa, je diagram poteka in opis celotnega postopka ter slikovni prikaz zaslonskih slik po korakih. Zaključek je namenjen pregledu celotnega stanja in pogledu v prihodnost ter morebitne možne posodobitve programa.

• Language: Slovenian
• Keywords: labview, avtomatizacija, varistor
• Work type: Bachelor thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2015
• PID: 20.500.12556/RUL-30506
• Publication date in RUL: 14.01.2015

Secondary language

• Language: English
• Title: Measurement automatization of the varistor U-I characteristics

Abstract

In the following work an update of the measurment site and programming of the aplication for measurement automatization of UI varistor characteristics is presented. The updated measuring site includes a personal computer and the high voltage testing instrument and replaces the old analog instrument, which did not have the possibility for connecting to a computer. The project started because of the demands of customers for a more accurate and computer aided measurements and also to achieve better traceability and analysis of measured data. For aplication programming the software Labview (by National Instruments) and 2410 SourceMeter (by Keithley) were used. The sourceMeter is fully managed by the computer. In the thesis I have described the varistor element, current measuring system, the new measuring system, short description of RS-232 and IEEE-488 (GPIB, General Purpose Interface Bus) data buses, program planning, customer demands, program code writting and code description, problem solving and cocnlusion with possible fututre upgrades. Chapter about the varistor element containes a description of its basic operation, various versions of varistors and their charateristics. The chapter on the current measuring system contains the old measurement procedure and the reasons for replacement with a new system. There are other options regarding the implementation of the measuring point and I have explained why the chosen solution is the most optimal. Description of the new system is an independent chapter, which describes the measurement procedure, the data connection between the computer and the instrument and the reasons for choosing these. Description of the program tells us what the program consists of and commands needed to communicate with the instrument. The design, development course and requirements for the program are described in this chapter. It also describes examples of unfulfilled requirements and explains the reasons for them. In the chapter on programming, Labview programming environment is discussed and also components and additional software packages which I used in programming. In the description of the program I have explained methods used to present the measurement results and the structure of the software project. Testing procedure for individual elements under test requires a seperate chapter in which I have described all of the needed numbers and codes that are transferred from the database and are essential for performing the measurement and processing of the results. Stress tests for varistors are also described as well as their U-I characteristics comparison and coeffcient calulations. During the programming, I have encountered some problems. Troubleshooting of them is described in the chapter about problem solving. The next chapter contains the program flow chart and the description of measuring procedure and step by step graphical screenshots. Conclusion chapter is dedicated for review of overall project status and future plans to find any possbile updates for the program.

• Keywords: labview, automation, varistor