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