8/10/2019 Bc a Novel Zcs-zvs-pwm Dc-dc Buck Converter for High Power and High Switching

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A

E4OVEL ZCS-ZVS-PWM DC-DC BUCK CONVERTER FOR HIGH POWER AND HIGH SWITCHING

FREQUENCY : ANALYSIS, SIMULATION AND EXPERIMENTAL RESULTS

Luiz Carlos de Freltiis

Douglas Ferrelra da Cruz

Valdelr Jose Farlas

h l v e r m l d e d e

Cedmral

d e U b e r l e n d l a

AV. Unlvaroltarlm

m/n

Cupus SanLa

I lonlsm

-

DELYE

- CETEC

Phone (034 ) - 236-5099

38-

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UBERUNDIA - f f i -

BRAZIL

Telex - 343264 -

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Fax - 1034 ) 2 -5099

ABSTRACT

Thls paper presents a DC-to-LK converter uslng

a novel ZCS-ZVS-PW cell for hlgh swltchlng

frequency and hlgh power operatlon. The proposed

cell consists of only one main switch plus an

auxlllary switch. wlth ZVS and ZCS swltchlng

characterlstlcs. respectively.

These switches. associated wlth resonant

lnductor and capacitor, yield zero voltage and zero

current swltchlng, provldlng hlgh efflclent

operating condltlon for a ulde range of power at

hlgh swltchlng frequency. The converter control 1s

done by uslng PWH technic, wlth constant frequency

operat on.

A cornplete analysis of the operating

prlnclples lncludlng output characterlstlcs.

relevant equations, state space phase, slmulatlon

and experlmental results for the Buck converter,

are presented .

1 - INTROWCTION

Associated wlth the Electrical

and

Electronlc

Englneerlng technological dev el op nt . many

appllcatlons of power converters demand

strlngently-speclfled hlgh power denslty

converters. Thls leads to the search of converters

that can provlde hlgh efflclency, small slze and

welght, low cost and hlgh power operatlon. So, the

advent of hlgher swltchlng frequencles 1s an

inevitable trend In the area of power converters

that also ylelds no acoustlc nolse and lmproved

translent response.

Although hlghly swltchlng frequencles are

deslred for power conversion, one has to conslder

the following problems when uslng

PWM

technlques

and high swltchlng frequency: High level of losses,

low efficiency, hlgh nolse levels and life

reductlon of the solld state sultches.

Considering the convenlence of using hlgh

swltchlng frequency and trylng to reduce Its

negative effects, there has been a great effort to

the development of Resonant Conversion techniques

where zero values of voltage or current can be

achleved durlng switchlng (non-disslpatlve

commutatlon).

The Quasl-Resonant Converters which are

frequency and/or pulse aodulated (QRC) (QRC-PWM)

111 I31

are important kinds of DC-to-DC Converters.

Usually, frequency modulated converters (QRC.1

show some control problems because the control

procedures are accomplished by frequency

varlatlons. As a consequence, designlng flltars and

transformers 1s dlfflcult in thls klnd of

converters.

On the other hand, QRCB-PVH do not show such

control problems, slnce they can operate wlth

constant frequency, but they also can not keep Its

loosless commutatlon characterlstlcs operating to

wide range of power. such as In m C m .

In the LC-PUM-RDC dc-dc converters, proposed

in [Q IS 1 and 161, the problems above descrlbed

are not present, but the swltchlng frequency is

strongly llmlted by resonant capacitor discharge.

In order to overcome those problems, thls work

presents the buck LC-PUM-SF-RDC wlthout Resonant

69

0-7803-0982-0/93 3.00 1993 IEEE

8/10/2019 Bc a Novel Zcs-zvs-pwm Dc-dc Buck Converter for High Power and High Switching

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Cycle Interruptlon.

Thls

new Buck Topology 1s an

improvement of the converter presented In [71.

Flgure 1 shows the novel ZCS-ZVS-PUH

commutatlon cell, called LC-PWH-SF-RDC, proposed in

thls paper.

It

Is

composed

by

only one maln and

only one awlllary swltches. They provlde non

dlsslpatlve swltchlng and hlgh frequency hlgh power

operatlon condltlon, wlthout the theoretlcal power

llmltatlon

of

the conventlonal

Quael

Resonant and

Quael-Resonant

PWH

Converters.

I P

Figure 1 - LC-PUM-SF-RDC cell without Resonant

Cycle Interruptlon.

Any converter can

be

performed by using the

proposed cell, through the approprlate conaxlon of

the I (actlve), C. (passlve)

and

p (passive)

termlnals showed In Flg. 1 [ZI.

Flgure Z shows a neu DC-to-DC Buck converter

topology, uslng the cell presented In thls paper

that lncludes

:

1 ) Complete ldentlflcatlon and analysls of the

varlous topologlcal converter modes during

one swltchlng cycle,

21

Relevant equatlons. output characterlstlcs

waveforms and state space phase,

Analysis slaulatlon and experimental results.

)

I -t

= 2

d

V 2 = V l / K

l * K