Mitsubishi Electric PSS**S72FT Manual page 40

<Dual-In-Line Package Intelligent Power Module>
1200V Mini DIPIPM with BSD Series APPLICATION NOTE
FWDi recovery characteristics can be approximated by the ideal curve shown in Fig.3-2-1, and its
dynamic loss can be calculated by the following expression:
Recovery occurs only in the half cycle of the output current, thus the dynamic loss is calculated by:
1
2

 Attention of applying the power loss simulation for inverter designs
・ Divide the output current period into fine-steps and calculate the losses at each step based on the
actual values of PWM duty, output current, V
current. The worst condition is most important.
・ PWM duty depends on the signal generating way.
・ The relationship between output current waveform or output current and PWM duty changes with
the way of signal generating, load, and other various factors. Thus, calculation should be carried
out on the basis of actual waveform data.
・ V ,V
CE(sat) EC
Publication Date: September 2015
I
EC
V
EC
Irr
Fig.3-2-1 Ideal FWDi recovery characteristics curve
Irr

Psw
 
(@ sin )

2 Irr Icp x


1

2


(@ sin )
Irr Icp x
8

and Psw(on, off) should be the values at Tj=125 °C .
trr
 
Vcc trr
4
 
(@ sin )
Vcc trr Icp x
4
  
(@ sin
Vcc trr Icp
, V , and Psw corresponding to the output
CE(sat) EC
40
t
Vcc
 
fc dx
 
)
x fc dx