pm75cs1d120 Mitsumi Electronics, Corp., pm75cs1d120 Datasheet - Page 45

• Manufacturer Part Number: pm75cs1d120
• Description: Mitsubishi Ipm L1/s1-series Application Note Igbt Modules
• Manufacturer: Mitsumi Electronics, Corp.

13. Average Power Loss Simplified Calculation
(1) VVVF Inverter
Applicability Range
It is not applicable in the thermal design of the device (limit design).
Assumption Condition
Calculation Equation
moment.
The output current corresponds to the output voltage change and this relationship is represented by power
factor cos . Therefore, the duty cycle of PWM corresponding to output current at arbitrary phase x is
V
Static power loss of IGBT is
Similarly, static power loss of FWDi is
On the other hand, dynamic power loss of IGBT is not dependent on the PWM duty and can be expressed as
the following formula.
As for dynamic power loss of free-wheeling diode, calculation is given by an example of ideal diode shown in
Fig.13.1.
It is applicable to total power loss calculation for selection of IGBTs used in VVVF inverters.
CE(sat)
Duty cycle of PWM is constantly changing and its value equal to time x
Output current of I
With inductive load rate of cos
PWM modulation used to synthesize sinusoidal output currents in VVVF inverters
PWM signal generated by comparing sinusoidal wave to triangular wave
Duty cycle of PWM among the rank of
and V
EC
at this moment are
PWM
Output
Vce
Vec
2
2
2
1
1
1
(
Average Power Loss Simplifi ed Calculation
sat
CP
0
0
2
(
(
Icp
Psw
Vec
Duty
((
current
)
sin x without ripple
) 1
(@(
(
Vce
on
sin
Icp
1
)(@
(
) x
Fig.13.1 Dynamic Power Loss of FWDi
sat
) 1
Icp
D
Icp
Vce
sin
)(@
Iecp
sin(
2
) x
(
sin
Icp
sat
sin
(
x
x
(
Icp
)(@
1
) x
Vec
sin
2
)
D
)
Icp
(@(
Psw
) x
~
sin
1
(
sin
45
) x
) 1
2
off
D
) x
)(@
Icp
(%
/
Icp
1
100
sin
Mitsubishi IPM L1/S1-Series Application Note
D
)
) x
sin
sin(
2
1
x
x
))
D : modulation rate
D
fc
sin(
)
2
1
dx
dx
x
D
2
)
sin
dx
x
at the corresponding
Sep. 2008