Razvoj AC-DC pretvornika z razponom vhodne napetosti od 85 V do 550 V : diplomsko delo

Fortuna, Žiga (author), Pirc, Matija (mentor)

Cilj diplomskega dela je bilo razviti zaporni stikalni napajalnik, ki ustreza varnostni kategoriji CAT III po IEC 60664. Napajalnik mora poleg običajnega napajanja z enofazno napetostjo 110 V ali 230 V, 50/60 HZ, omogočati tudi napajanje z medfazno napetostjo. To pomeni, da mora delovati v razponu vhodnih napetosti med 85 V in 550 V efektivne vrednosti. Na izhodu pa mora zagotavljati 19,5 V ter 30 W moči. Najprej smo izbrali primeren krmilnik za krmiljenje napajalnika ter preučili njegovo delovanje. Z upoštevanjem zastavljenih ciljev smo izračunali vse elemente stikalnega napajalnika, najprej vrednosti elementov, ki določajo osnovne lastnosti napajalnika, kot so izhodna napetosti in moč ter zagonski čas, nato pa še vrednosti elementov za sklope, ki so namenjeni filtriranju, glajenju napetosti in dušenju hitrih sprememb napetosti in toka. Po izdelavi sheme smo s programom Altium Designer, dali narediti tiskano vezje in napajalnik sestavili. Opravili smo električne meritve, kjer smo ugotovili, da je izhodna napetost napajalnika 21 V, izhodna moč pa narašča do maksimalno 35 W s povečevanjem izhodnega bremena. Izkoristek napajalnika je pri najmanjšem izmerjenim bremenom, ki znaša 500 Ω, le 40 %. Z povečevanjem bremena oziroma z zmanjševanjem upornosti pa se izkoristek povečuje. Pri 75 Ω bremenu se izkoristek dvigne na 70 % in ostane približno enak čez ostale manjše upornosti. Največji izkoristek je izmerjen pri 14 Ω in 21,3 V. EMC meritve se pokazale, da napajalnik deluje dobro v celotnem frekvenčnem območju in je narejen v skladu s standardi.

• Language: Slovenian
• Keywords: stikalni napajalnik, zaporni pretvornik, napajalnik z širokim razponom napetosti
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FE - Faculty of Electrical Engineering
• Place of publishing: Ljubljana
• Publisher: [Ž. Fortuna]
• Year: 2021
• Number of pages: 48 str.
• PID: 20.500.12556/RUL-129716
• UDC: 621.3(043.2)
• COBISS.SI-ID: 75543299
• Publication date in RUL: 07.09.2021

Secondary language

• Language: English
• Title: Development of an AC-DC power converter with input voltage range from 85 V to 550 V : visokošolski strokovni študijski program prve stopnje Aplikativna elektrotehnika

Abstract

The aim of the thesis was to develop a switching flyback power supply that corresponds to the safety category CAT III according to IEC 60664. In addition to the usual power supply with a single-phase voltage of 110 V or 230 V, 50/60 HZ, the power supply must also provide power supply with interphase voltage. This means that it must operate in the input voltage range between 85 V and 550 V rms. At the output, it must provide 19.5 V and 30 W of power. We first selected a suitable controller to control the power supply and examined its operation. Taking into account the set goals, we calculated all elements of the switching power supply, first the values of the elements that determine the basic properties of the power supply, such as output voltages and power and start-up time, and then the values of elements for assemblies intended for filtering, smoothing voltage and damping rapid changes in voltage and current. After making the scheme, we made the printed circuit board with the Altium Designer program and assembled the power supply. We performed electrical measurements, where we found that the output voltage of the power supply is 21 V, and the output power increases to a maximum of 35 W with increasing output load. The efficiency of the power supply is only 40% at the minimum measured load of 500 Ω. By increasing the load or by reducing the resistance, the efficiency increases. At 75 Ω load, the efficiency rises to 70% and remains approximately the same over other lower resistances. The maximum efficiency is measured at 14 Ω and 21.3 V. EMC measurements have shown that the power supply works well over the entire frequency range and is made according to the standards.

• Keywords: switching power supply, flyback converter, wide range power supply