(. . 7.17), , IG FWD, .
, (7.3)
, ; k1 = 1,21,5 , ; k2= 1,1 1,2 ; η ; U , .
IGBT () Ic ≥ Ic max.
. 7
IGBT , .
IGBT
, (7.4)
Ic = Ic max /k1 , A; D = t/T ≈ 0,95 ; cosθ ≈ cosφ ; Uce(sat) IGBT Ic j = 125 ( Uce(sat ) = 2,12,2 ).
IGBT
, (7.5)
t(on), t(off) IGBT t(on) t(off) , ( t(on) = 0,30,4 ; t(off) = 0,60,7 ); U IGBT, ( , ͖); fsw , ( ), 5000 15 000 .
IGBT
PQ = PSS + PSW. (7.6)
. (7.7)
I ≈ Ic , ; U ( ) I, .
PDR =(Irr Ucc trr fsw)/8, (7.8)
Irr , (Irr ≈ I); trr , ( 0,2 c).
PD = PDS + PDR. (7.9)
IGBT
PT = PQ + PD = PSS + PSW + PDS + PDR . (7.10)
. 7
, , IGBT .
Rth(f-a), /, IGBT/FWD (/ )
, (7.11)
= 4550 ; = 90110 ; T , , IGBT/FWD; Rth(c-f) IGBT/FWD, /.
|
|
IGBT, ,
Tja = Tc + PQ Rth(j-c)q, (7.12)
Rth(j-c)q IGBT , /. Tja < 125.
FWD, ,
Tjd = Tc + PDRth(j-c)d , (7.13)
Rth(j-c)d FWD , /.
jd < 125.
jd ≥ 125 , Rth(f-a), .. .
Ud = kc. U, (7.14)
kc. ; kc. = 1,35 ; kc. = 0,9 .
. 7
, (7.15)
n IGBT/FWD .
Iνm = kcc Idm, (7.16)
1,045 - LC -, ; = 1,57 .
( )
Uvm = k√2Ukkc + Δ Un, (7.17)
≥ 1,1 ;
> 1,15 ; Δ Un = 100150 .
( Ivm) ( Uvm /100).
(Id = Idm / k1)
(7.18)
kcs = 0,577 ; kcs = 0,785 ; Ron , ; Uj , , 50 (Uj + RonIdm / k i ≤ 1 1,3 ); mv .
.
, (7.19)
Rth(c-f) , /.
. 7
, PDV , .
, (7.20)
Rth(c-f)DV , /; nD .
, TjDV < 140.