Izrada modela frekvencijskog pretvarača u programskom paketu Matlab

undergraduate thesis

• Title (english): Frequency converter model in Matlab
• Author: Dean Leibner
• Mentor: Mario Vražić (mentor)
• Committee member: Mario Vražić (predsjednik povjerenstva)
• Committee member: Ivan Gašparac (član povjerenstva)
• Committee member: Zlatko Hanić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; Zagreb
• Defense date and country: 2014-07-14, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering

Abstract

U ovom Završnom radu obrađena je jedna topologija frekvencijskog pretvarača, s dvije različite metode regulacije struje. To su histerezni i sinusni PWM pretvarač. Oba modela napravljena su u programskom okruženju MATLAB. Uz teorijsku podlogu histerezne i sinusne PWM modulacije, potrebne za razumijevanje dobivenih simulacija, obrađene su i Fourierova analiza za prikaz amplituda harmonika te THD kao utjecaj harmonika na valni oblik ulazne struje u pretvarač. U simulacijama su se mijenjali razni parametri te se promatrao utjecaj promjene parametara na amplitude harmonika. Rezultati su kod obje metode regulacije struje približno jednaki. Detaljnijom analizom rezultata možemo vidjeti kako su rezultati sinusne PWM modulacije ipak nešto bolji od histerezne. To vidimo po manjim amplitudama harmonika, a veći iznos harmonika uzrokuje veću deformaciju ulazne struje. Također sinusni PWM ima još prednosti u odnosu na histereznu regulaciju. Jedna od prednosti je konstantna frekvencija sklapanja poluvodičkih ventila čime se mogu bolje kontrolirati gubici na poluvodičkim ventilima. Priloženi su grafički te numerički rezultati simulacija.

Abstract (english)

In my final thesis I have made two different kind of frequency converters. Actually the only difference between them is how they regulate current. First one is the simplest one that exists and it has hysteresis band control. The other one is the most popular for controlling the speed of engines and it has sinusoidal PWM. Both models were made in MATLAB. I had written theory about hysteresis band control and sinusoidal PWM, and also about Fouriers analasis to show the amplitudes of harmonics and THD to see the influence of the harmonics to the current waveform in the entrance of the frequency converter. I have changed the parameters to simulate the models and see what difference happens.The results of the both methods are almost the same. But if we closely look at the results we can see that sinusoidal PWM is slightly better than hysteresis band control. We see that on lower amplitudes of harmonics and that is better because the higher amplitude causes the bigger deformation of the current. Also sinusoidal PWM has some other advantages. One of them is constant frequency for switching the semiconductor valves. That means that the losses on the semiconductor vavles can be better controlled. I had put the results as pictures and also given it in numbers.

• Keywords: frekvencijski pretvarač; histerezna modulacija; sinusna PWM modulacija; THD
• Keywords (english): frequency converter; hysteresis band control; sinusoidal PWM; THD
• Language: croatian
• URN:NBN: urn:nbn:hr:168:878123
• Study programme: Title: Electrical Engineering and Information Technology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka elektrotehnike i informacijske tehnologije (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka elektrotehnike i informacijske tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2018-02-05 17:40:15