Closed-loop thyristor current control
System- and communication configuring D7-SYS - SIMADYN D
5-43
Edition 06.2002
ITDC
hard-
ware
0
1
0
1
0
1
Fault
evaluation
Pulse
position
monitor-
ing
Double
firing
Control
WAF
YEA
ZPA
(ZXA)
QSF
(ZLA)
DZM
ZAH
PC6.dsf
AQL
AWS
XAS
EN
ICC
DZ
WAS
[ASG]
-> [°]
[ASG]
-> [°]
DAG DAW
B
IT
3
/
T
E
S
T
B
IT
8
/
s
h
if
t
to
i
n
v
.o
p
.
90°
-
LDL
LDU
AUS
Release
DIL
DIZ
Control word HW
Fig. 5-24
Function diagram of PC6
It is possible to evaluate the accuracy of the gating unit by monitoring the
pulse positions (this can be parameterized).
The firing angle setpoint is switched-over from the switch-over logic stage
(command word SOL.QCC
→
PC6.ICC).
Corresponding to the selected mode, the inputs
PC6.WAS
(closed-loop controlled operation)
PC6.AQL
(test operation, open-loop controlled)
PC6.AWS
(shift to inverter operation)
are used as manipulated variable to generate the firing pulses.
In the “Closed-loop/open-loop controlled operation” modes, the firing
angle setpoints are fed through a ramp-function generator.
Separate change time constants are entered in the form of gradients for
the two directions. The gradients PC6.DAG specify the max. angular
change / sampling cycle ([°] / [TA]) in the direction of rectifier operation,
PC6.DAW the max. angular change / sampling cycle towards inverter
operation.
The ramp-function generator is de-activated in the “Shift to inverter
operation” mode.
The absolute limiting of the control limits are always active using
parameters
PC6.LDU
(inverter control limit) and
PC6.LDL
(rectifier control limit)!
The limits, configured at current controller FB CPI.ALU, .ALL only act, if
they have lower values than those at the absolute limits at FB PC6.
Firing angle
setpoint
Control limits for
the
rectifier and
inverter
