Zasnova, izdelava in testiranje SEPIC pretvornika

NOVINŠEK, BLAŽ (author), Petkovšek, Marko (mentor)

Hella Saturnus Slovenija je podjetje, ki se ukvarja z razvojem in proizvodnjo svetlobne opreme za avtomobilsko industrijo, zato imajo opravka z različnimi napetostnimi pretvorniki, saj razni elektronski sklopi (npr. žarometi) za svoje delovanje potrebujejo drugačno napetost od tiste, ki jo zagotovi avtomobilski akumulator. Za svojo diplomsko nalogo sem se odločil izdelati enega izmed takšnih pretvornikov, in sicer SEPIC (single-ended primary-inductor converter) pretvornik, ki se ga bo lahko v prihodnosti uporabljalo tudi za testiranje v podjetju. SEPIC pretvornik je vrsta stikalnega enosmernega pretvornika (ang. DC/DC converter), ki transformira vhodno napetost navzgor ali navzdol, odvisno od aplikacije. Deluje po principu izmenjave energije med dušilkami in kondenzatorji v vezju. Pretvornik sem zasnoval s krmilnim vezjem LM51571-Q1 podjetja Texas Instruments. Izdelan pretvornik omogoča pretvorbo spreminjajoče vhodne napetosti v konstantno izbrano izhodno napetost. Z izračuni sem določil ustrezne komponente za delovanje pretvornika, izris električne sheme in načrt postavitve elementov na tiskanino (ang. layout) pa sta bila narejena v programu KiCad. Med testiranjem izdelanega tiskanega vezja se je izkazalo, da je bilo delovanje v skladu s pričakovanji. Izhodna napetost je bila konstanta, brez valovitosti. Elektromagnetna kompatibilnost vezja (ang. electromagnetic compatibility - EMC) je ustrezala IEC standardu CISPR 25:2021 razreda 4, kar pomeni, da vezje še ne dosega zahtevanega 5 razreda, ki ga narekuje standard za avtomobilsko industrijo.

• Language: Slovenian
• Keywords: enosmerna napetost, SEPIC pretvornik, krmilno vezje, enosmerni pretvornik (DC/DC), avtomobilska industrija, elektromagnetna kompatibilnost
• Work type: Bachelor thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2023
• PID: 20.500.12556/RUL-146817
• COBISS.SI-ID: 156707843
• Publication date in RUL: 14.06.2023

Secondary language

• Language: English
• Title: Design, manufacture and testing of a SEPIC converter

Abstract

Hella Saturnus Slovenia is a company that develops and manufactures lighting equipment for the automotive industry, and therefore deals with different voltage converters, as various electronic assemblies (e.g. headlights) require a different voltage to that provided by the car battery. For my diploma, I decided to build one of these converters, a SEPIC (single-ended primary-inductor converter) converter, which can also be used for in-house testing in the future. SEPIC is a type of switching DC/DC converter that transforms the input voltage to a higher or lower level, depending on the application. It works on the principle of energy exchange between the inductors and capacitors in the circuit. I have designed the converter with the LM51571-Q1 controller from Texas Instruments. The converter I have designed allows the conversion of a varying input voltage to a constant selected output voltage. I used calculations to determine the appropriate components for the operation of the converter. The schematic and the layout of the circuit were drawn in KiCad. During testing of the PCB, the performance was as expected. The output voltage was constant, without fluctuations. The electromagnetic compatibility (EMC) of the circuit was in accordance with the IEC standard CISPR 25:2021 class 4, which means that the circuit does not yet meet the required class 5 of the automotive standard. Despite the performance of the circuit, improvements could be made, particularly in the area of EMC. The circuit complies with the IEC CISPR 25:2021 class 4 standard, but for use in vehicles it is necessary to achieve a class 5, which has certain stricter maximum EMI values. Electromagnetic interference could possibly be limited by the use of a shield can or a ferrite bead.

• Keywords: DC voltage, SEPIC converter, controller, DC-to-DC converter, automotive industry, electromagnetic compatibility