Zaščitni stikali nizkonapetostnega enosmernega presmernika

PERUŠKO, LUKA (author), Zajec, Peter (mentor)

Magistrska naloga podaja zasnovo, teoretično obravnavo, načrtovanje, izdelavo in testiranje polprevodniških odklopnikov za varno sklopitev dveh virov na dvosmerni pretvornik. Na začetku je predstavljena topologija sistema s poudarkom na konfiguraciji priklopa virov. S simulacijo je dokazano, da se s spremenjenim priklopom virov občutno zmanjšajo izgube na enem od odklopnikov. Zaradi tega sem se odločil nižje napetostno stikalo premakniti na ničelno GND vez, kjer ima manjše izgube. Osrednji del magistrske naloge podaja načrtovanje vezja s programskim orodjem Altium. Predstavljeni so posamezni deli vezja in njihove komponente v logičnem zaporedju. Vezje mora varno sklopiti dva vira in zagotoviti hiter odklop v primeru napak. Od ostalih sistemov, ki opravljajo enako funkcijo se predlagana rešitev razlikuje po lokaciji stikal (''low side'') in bolj kompleksnem sistemu mehkega zagona v primeru kapacitivnih bremen. Ena izmed omejitev te rešitve je nezmožno delovanje zaščitnih stikal, ko je prisoten le vir višje napetosti. Na koncu so še predstavljene meritve sistema, s čimer se prepričamo, da naprava opravlja zastavljene funkcije.

• Language: Slovenian
• Keywords: nizkonapetostni DC odklopnik, varnostno stikalo, sistem dveh napetosti, topologija sistema dveh napetosti
• Work type: Master's thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2019
• PID: 20.500.12556/RUL-106868
• Publication date in RUL: 22.03.2019

Secondary language

• Language: English
• Title: Safety switches of low-voltage DC-DC converter

Abstract

This master's thesis explains theoretical operation, schematic design, production and testing of bidirectional mosfet load switch, implemented for protecting system's with two voltage levels. In the beggining, the topology of the system is presented with emphasis on different connection configurations of the DC/DC converter. As a consequence of a different topology, there is a lower current running through the GND link, therefore we have decided to locate a load switch to this link. A big part of the thesis is describing the board design in Altium. Each part of the board is presented apart from each other in a logical flow. The board had to fulfil the folowing functions: overvoltage protection, undervoltage protection, bidirectional overcurrent protection and soft start of highly capacitive loads. From other system's on the market our system differs with the location of the load switch and a more complicated approach to soft starting of capacitive loads and is unable to work with only an high voltage source present. At the end of this document, the results of the functionality testing are presented, to prove that the system works as intended.

• Keywords: low voltage DC circuit breaker, load switch, two voltage level systems, DC/DC converter connection topology