Development of Fixed Frequency High Efficiency Flyback Converter for Satellite Power Supply
Authors
Lambæk, Victor Daugård ; Olsen, Anton Hviid ; Pham, Khoi Minh Cao
Term
4. term
Education
Publication year
2026
Submitted on
2026-05-28
Pages
98
Abstract
Satellites rely on efficient power supplies. This project studies flyback converter variants to improve efficiency over a conventional flyback. A bidirectional flyback converter is chosen because it can enable soft switching (turning devices on/off at low voltage or current), reducing switching losses; however, large peak currents are a key challenge that must be solved. The transformer turns ratio is selected to minimize the combined RMS current in all windings, but this requires a large air gap that increases leakage inductance. Using the extended cantilever model, the effective turns ratio and leakage inductances are estimated, and clamps and snubber circuits are designed to absorb the energy stored in leakage inductance. Compared to theoretical data for a conventional flyback, the prototype developed here achieved only 60–70% efficiency. To improve performance, the transformer’s leakage inductance should be reduced to lower losses in snubbers and clamps. These improvements are needed before deciding whether the bidirectional flyback converter is suitable as a replacement for the conventional flyback.
Satellitter er afhængige af effektive strømforsyninger. Dette projekt undersøger varianter af flyback-konvertere for at øge effektiviteten i forhold til den konventionelle flyback. En bidirektionel flyback-konverter vælges, fordi den kan muliggøre soft-switching (tænd/sluk ved lave spændinger/strømme), som reducerer koblingstab; men store spidstrømme er et centralt problem, der skal løses. Transformatorens vindingstalforhold vælges for at minimere den samlede effektivstrøm (RMS) i alle viklinger, men det kræver en stor luftspalte, som øger lækinduktansen. Med den udvidede cantilever-model estimeres det effektive vindingstalforhold og lækinduktansen, og der designes klemmer og snubber-kredsløb til at absorbere den energi, der lagres i lækinduktansen. Sammenlignet med teoretiske data for en konventionel flyback-konverter opnår prototypen i projektet kun 60–70% effektivitet. For at forbedre ydelsen bør transformatorens lækinduktans reduceres for at mindske tabene i snubbere og klemmer. Disse forbedringer er nødvendige, før man kan afgøre, om den bidirektionelle flyback-konverter er egnet som erstatning for den konventionelle flyback.
[This apstract has been rewritten with the help of AI based on the project's original abstract]
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Olsen, Anton Hviid: