Upravljanje mekim prekidanjem kod dvosmernog buck/boost pretvarača zasnovano na elementu sa strujno regulisanim koeficijentom magnetne sprege
Zero-voltage switching control of an bi-directional buck/boost converter with variable coupled inductor
Author
Pajnić, MilanMentor
Pejović, PredragCommittee members
Vukosavić, SlobodanJanda, Žarko
Đurić, Radivoje
Despotović, Željko
Metadata
Show full item recordAbstract
Upravljanje mekim prekidanjem kod dvosmernog buck/boost pretvarača zasnovano na elementu sa strujno regulisanim koefcijentom magnetne sprege
Glavni ciljevi istraživanja predstavljenog u okviru ove disertacije su razvoj nove magnetno simetrične strukture, sa strujno regulisanim koefcijentom sprege i simetrične
raspodele magnetnog fluksa, pogodne za primenu u više-faznim pretvaračima i razvoj
novog načina upravljanja mekim prekidanjem energetskih prekidača u slučaju dvosmernog buck/boost pretvarača, putem strujno regulisanog elementa upravljive magnetne
sprege.
Postojeće realizacije magnetnih regulatora sa strujno regulisanom magnetnom spregom mogu se podeliti u dve grupe. U prvu grupu spadaju magnetno nesimetrični elementi spregnutih induktivnosti sa strujno regulisanim koefcijentom sprege, kod kojih
vrednost indukovanog napona, usled promene fluksa, nije jednaka u svim namotajima
elementa i koji se kao takvi ne mogu smatrati pogodnim za primenu u višefaznim energetskim pretvaračima. Drug...u grupu elemenata čine magnetno simetrične strukture,
kod kojih magnetno polje usled struje predmagnećenja uvećava jednosmernu radnu
tačku magnetnog materijala u celom jezgru i time značajno uvećava gubitke u magnetnom materijalu. Magnetno simetrična struktura razvijena u okviru ovog istraživanja
sačinjena je od namenski izrađenih feritnih jezgra, gde su kontrolne magnetne grane
smeštene simetrično, na jednakim udaljenostima od radnih grana. Takođe, vazdušni
procepi u magnetnom materijalu su distribuirani i postavljeni u obe radne magnetne
grane, kako bi na taj način magnetno polje koje potiče od struje predmagnećenja bilo
ograničeno samo u kontrolnim magnetnim granama strukture. Realizacijom strukture na prethodno opisan način, omogućena je regulacija vrednosti koefcijenta sprege
između radnih namotaja putem struje predmagnetizacije, dok je distribucija jednosmernog magnetnog polja ograničena samo u kontrolnim granama magnetne strukture.
Distribucija jednosmernog magnetnog polja u predloženoj magnetnoj strukturi, verifkovana je primenom simulacije, metodom konačnih elemenata (Finite Element Method
– FEM). Električne osobine predložene strukture predstavljene su pomoću analitičkog
modela, gde je korelisanje parametra modela sa realizovanom strukturom izvršeno na
osnovu eksperimentalno dobijenih rezultata. Maksimalan opseg promene kontrolisanevrednosti koefcijenta sprege predstavljen je u odnosu na različite vrednosti odnosa
reluktance radne i kontrolne magnetne grane. Takođe, u okviru istraživanja, predstavljena je analiza uticaja promenljive vrednosti koefcijenta sprege elementa spregnutih
induktivnosti na performanse dvo-faznog boost DC-DC pretvarača, koji radi u kontinualnom režimu vođenja energetskih prekidača. Pored predstavljene analize uticaja
promenljive vrednosti koefcijenta sprege, naveden je i primer određivanja parametara
predložene magnetne strukture u slučaju dvo-faznog boost DC-DC pretvarača.
Main goals of the research presented in this dissertation are development of new symmetrical magnetic structure, with current regulated value of the coupling coefcient
and symmetrical distribution of the magnetic flux, suitable for use in the multi-phase
power converters, and development of new approach for soft-switching control in case
of the bi-directional buck/boost power converter, by utilizing the coupled inductor with
the variable coupling coefcient.
Existing realizations of the magnetic regulators with the current controlled magnetic coupling can be divided into two groups. The frst group includes magnetically
asymmetric coupled elements with the current controlled magnetic coupling, in which
value of induced voltage, due to variable magnetic flux, isn’t equal in all windings of
the element, and which as such cannot be considered suitable for use in multiphase
power converters. The second group of elements consists of the magnetically symmetric structures, in which the magnetic f...eld, due to the DC bias current, increases the
bias magnetic feld in the magnetic material, throughout the magnetic core, and thus
signifcantly increases the losses. The magnetically symmetric structure developed in
this research is implemented using custom made ferrite cores, where the control magnetic legs are arranged symmetrically, at equal distances from the main magnetic legs.
Also, the air gaps in the magnetic material are distributed and positioned in both
main magnetic legs, so that the magnetic feld originating from the DC bias current
is limited only in the control magnetic legs of the structure. The realization of the
structure in the manner described above enabled the regulation of the value of the
coupling coefcient between the main windings by the mean of DC bias current, while
the bias magnetic feld was limited only in the control legs of the magnetic structure.
The distribution of the DC bias magnetic feld in the proposed magnetic structure
has been verifed using a Finite Element Method (FEM) by simulation. The electrical
properties of the proposed structure are presented using an analytical model, where
correlation of the model parameters with the realized structure was performed based
on the experimentally obtained results. The maximum range of variation of the control value of the coupling coefcient is presented in relation to different values of the
ratio of the reactance of the main and the control magnetic legs.
Also, within this research, an analysis of the influence of the variable value of
the coupling coefcient on the performance of a two-phase boost DC-DC converter,
operating in the continuous conduction mode is presented. In addition to the presented
analysis of the influence of the variable value of the coupling coefcient, an example
of determining the parameters of the proposed magnetic structure in the case of a
two-phase boost DC-DC converter is given.
Faculty:
Универзитет у Београду, Електротехнички факултетDate:
05-06-2020Projects:
- Innovative electronic components and systems based on inorganic and organic technologies embedded in consumer goods and products (RS-32016)
- Development of the methods, sensors and systems for monitoring quality of water, air and soil (RS-43008)