Download Inverter Circuit, Construction of Equivalent Circuit - Power Electronics | ECEN 5797 and more Assignments Electrical and Electronics Engineering in PDF only on Docsity! 3-)
3 MODELING DIODE REVERSE RECOVERY (30 POINTS)
In the half-bridge inverter ciccuit illustrated in Fig. 3 (see Pig. 4.11 of the text), the diodes exhibit a
reverse recovery process with recovered charge Q, and reverse recovery time /,. The transistors have for-
ward voltage drop V, and the diodes have forward vellage drop Vp.
Fig. 3 Flalf-bridge inverter
circuit of Problem 3
You may assume thal the (rausistors do net conduct reverse current. The converter operates in the contin
uous conduction mode, ~ith negligible inductor current ripple.
(a) For the caye when D > 0.5, sketch the waveforms of v,(z) and 1,(). Derive au averaged equiva-
lent cuicuit that models the steady-state behavior oF the circuit, irclading the effects of diode
reverse recovery and the semiconductor forward vallage drops (15 points).
(b) Repeat part (a) for the case when D < 0.5 (15 points).
kh t da Ve >O
> & FO an
Dr z L OAS is wch Ya onl
eo
art (@ pesrble wes te Atve d
uy, )
Capacitor charge. balance \
V
ZEy eo = 44> a Tag
\nduetor’ Valt- second lealan ca.
LuL> = O ®
nate VL VR Ng
So CV = ove? -\a-V
. t
wh 2vg> = D(a\,-Vyp) 7D Vo
so 0 = Daw -VP) HD Vy “Ng WV
é
> oF (ad-i)Vq — Vy ~ DNS WV
aueTag wput curreat ] :
‘ — tt. On .
4t,> = DILt+ Tet oe = Tp
overage imput current #21
node eguaton : a zt, So ee nt
( = Ziy> - > «7! t, ar 2
Eig > = Sip> a DIL+ Te t+ = Tp
Lvg> = Y@yr\y) tv! V+ z
le> = WD Ory tre (-
<ig> = Der e+ te CT)
ductor” velt- second balance
Z2N,> =o 2 op > - V5 ~V
© =2DW+DdVy +d! V_ =\g - V
6 ~P- DIN, +DV, + DY Vy
ONerase. vmpat Curent sh 2.
Ze >a tT. = p. a + Qr tr
£ B (-T.) = + z (2)
fy>= eo Ted,
=
ts
Soe ty, = DEL + e+ Cn)
wal ext Arta
gla cna
3-7
\ dopende.st Seurees with trans tomes
repiace
Bs before 4