Hitachi IGBT Module Application Manual
5.5.1.2.2
Recovery Power Dissipation
Supposing that the current peak value is
Equation 23:
I
ave
=
2
⁄ π
!
2 I
0
2 I
0
, the forward average current (as calculated using
For the above I
ave
(per pulse), obtain the recovery power dissipation, specify it as E
then use Equation 24 to obtain the value for P
rr
.
Equation 24:
P
rr
= E
rr
!
f
c
/2
5.6
Thermal Impedance and Heat Dissipation Design
5.6.1 Thermal Impedance
Thermal impedance between junction and case (R
th
( j - c )) of IGBT and diode is restricted in the
device specifications.
Note:
Thermal impedance values between case and heat sink
(R
th
( c - h )) of specific Hitachi IGBT modules can be supplied
individually upon request.
5.6.2 Definition of Temperature Measurement Point
th
( o - c ) and R
th
( c - h ) are based on the indicated measurement
points.
Figure 36. Definition of T
c
and T
h
Measurement Points
Legend:
T
c
T
h
Case temperature of module
Heat sink temperature
34