Working Principle; Volt-Ampere Characteristic - SanRex SANARG 180AP Operator's Manual

§2.2 Working Principle
The working principle of SANARG 180AP welding machines is shown as the following figure.
single-phase 120/240V work frequency AC is rectified into DC
380V)
, then is converted to medium frequency AC (about 44K Hz) by inverter device (IGBT module),
after reducing voltage by medium transformer (the main transformer) and rectifying by medium
frequency rectifier (fast recovery diodes), then is outputted DC or AC by selecting IGBT module. The
circuit adopts current feedback control technology to insure current output stably. Meanwhile, the
welding current parameter can be adjusted continuously and steplessly to meet with the requirements of
welding craft.
single-phase AC
DC
Rectif
ier
120-240V,
50/60HZ
§2.4 Volt-Ampere Characteristic
SANARG 180AP welding machine has an excellent volt-ampere characteristic, whose graph is
shown as the following figure. The relation between the conventional rated loading voltage U
conventional welding current I
≤600A，U
When I
2
（V）
U
2

Volt-ampere characteristic

50
34
10
0
SUMMARY
Trans
AC
DC
Invert
PFC forme
er
r
Current feedback
is as follows:
2
=10+0.04I (V); When I
2 2
Working
point
, then by PFC circuit, DC(about
AC DC
Rectif Invert
ier er
t
Control signal
control
＞600A,U
=34(V)
2 2
The relation between the
conventional loading
voltage and welding current
（A）
600 I
2
8
Hall
AC or DC AC or DC
devic
e
and the
2