This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: ECE433Exam 1, March 1, 2010
Name: PUID: l—a) For an ideal buck converter, derive the equation for the output voltage ripple and express it in terms of duty cycle, switching frequency, capacitance, and output voltage (8 points). a? it <LG>TS :: a g 041% 1st g
2 1b) For an ideal boost converter, derive the value for Lmt in terms of duty cycle,
switching frequency, and load, at the boundary of DCM and CCM (6 points). "it V65
ﬂ/é’jﬂ, 1c Fig. 1 shows a source and load that someone desires to be connected. Show the
switch matrix for the system and determine the conditions necessary to satisfy KCL and
KVL. Write the switch state matrix and propose a switching strategy. (6 pts) citor M
bke wwéfage
Swarm (WM? be Marl?) ‘ CH fill (J
M:
izz+iaz<i [I ajdl” 0 I
kUiWMxé ailltq}12>l0T?/Z«f$2/)I%QS 0 t ’V g  2) For the given converter shown in Fig. 2, V9 = 24V,L = 10mH,C = 10,11F,R = 109,1) = 0.5. r “
91/) L62, ((0710) Fig. 2 a) Assume that the diode and switch have a voltage drop of VDonand VTon
during the conduction, respectively. Determine the voltage conversion ratio
as a function of VDon, Vron , and D (4 points). b) Assume that VDon = 1V and VTon = 1V, plot the voltage and current of each
device, i.e. switch, diode, inductor, and capacitor in steadystate. Determine
ML and AVC and include them on the graphs (for each graph show the
magnitude and time information) (12 points). c) Determine the efficiency of the converter under the condition of part b)
(4 points). a) 9 654,073 3 QQGBD‘ :OYF
(UL : \C’ [47m \ _» ‘_ L,,‘l)0wt~2,,m
C“ ”if” 7 6 b) «013:0 ,4; 0154,97?) +C\’D)’E§CIL’§%) :0 PM , (WatCM) n: /. ' ﬂ ‘
m ‘
P 4Vdn‘ Lm>
me mu
9T5
‘ ‘ T : 01L
4L&‘>:Jﬁj LQIM‘JﬁQTL OS)
2 1/
WM , M,
RV}. Oil, ﬂlfm ' D 3) Extra Credit Question (10 points)
An ideal interleaved buck converter is shown in Fig. 3. This is equivalent to
parallel combination of two buck converters to a common capacitor and load.
The switches Q1 and Q2 operate 180°out of phase with the same switching
frequency and the same duty cycle. The control signals of the switches are shown
in Fig. 3. a) Determine the voltage conversion ratio M (D) = Vow/Vin . b) Determine the DC component of the inductor currents and also inductor
current ripples. Plot the inductor currents. c) Determine the amplitude of the output voltage ripple and compare it with
that of a conventional buck converter you derived in problem 1a). What is
the advantage of an interleaved buck converter over a conventional buck
converter? 5 . (ﬂaw/5310A!” Fig.3 I" ’ 4w.»— cm goryaﬁh’ W) +LI’0)”R(4fazf» :0 ‘ S ‘ @2005”?
4®L1>T5 :0 a 4.310 73w; ,z/M) 741mg. («LE2H) :q “PM ‘ *1“ “if “iii am be mgmam a
DVM’VS Smﬂle bug/L (mom/L6H A5 a ram 4% gem/WCMW MM I23 cpxwml Mg a SWIM VFW/e, % Hm Watzﬂe ﬂop/e a3 #72 WW WW be Xmaer. QL Mare Wm M WW6“ (4/1/06 IMHW 5 ‘Tkenﬂh ﬂaw: Sh'ﬂjf MIL/65h #16 SLMMeX Wow 1% 3600 where
n {s 'er mmbcraﬁ mt/eﬁfelff M 7% [Maud dmﬁgmrcgm Mapmvﬂ (an be plane ﬁéwﬁx Bazaﬂ (MWQZX 55/684 HoMWOf/U M2986 6011 MM teal/6% 361951? anerfer }‘ ...
View
Full Document
 Spring '08
 Staff

Click to edit the document details