Principle; Main Main Circuit - Kemppi Minarc 150 Service Manual

Operation principle
Minarc power sources are"dual-Forward" inverters, controlled by PWM technology.
Switching components are IGBT transistors. The operation frequency is ~ 80 kHz.
Below is a picture of the "dual-forward" inverter operation principle.
~ + 320 V
When IGBTs V1 and V2 are non-conductive no power is transferred. Power is altered by
changing the transistor´s timing (PWM).
Main circuit
X1
0
2
V
1
3
R
1
2
V
2
3
R
+ t
X3
R30
K1
X5
Primary circuit connection, Minarc 150/150 VRD.
V1
V2
X11/12
L2
5
1 5 9
C C C
+ t
0
R23
1
C
105
1/3
R9
6
1 3
1
V
C
L1
4
C
,
3
V11
C
,
2
C
VDC
5
,
0
.
x
a
M
13µs
6
V
,
5
V
,
4
V
X13
3
V
1
,
0
7
0
V
T
X12
2
V
,
1
2
V
T
0
1
V
,
9
V
,
8
V
t
4