Closed-loop thyristor current control
System- and communication configuring D7-SYS - SIMADYN D
5-17
Edition 06.2002
With the ohmic voltage drop:
XC
RA
R
∗
=
∗
∑
=
armature
I
YUR
,whereby RA should
be calculated with the determined armature resistance:
[ ]
(
)
(
)
(
)
(
)
CAV
NF
CAV
ARC
EMF
ARV
EMF
NF
RA
∗
∗
=
armature
R
With the inductive voltage drop:
(
)
1
n
XC
n
XC
TA
RA
dt
di
L
EMF.YUL
−
−
∗
=
=
The inductive voltage drop is only approximately calculated using this
formula and is therefore not so precise that this value can be used for
other calculations.
The
EMF
value is normalized to the no-load line supply amplitude
π
π
2
3
ˆ
2
3
13
∗
=
∗
AAV
L
V
and output.
YEM
AAV
RRV
2
3
EMF.YEV
∗
∗
π
=
The EMF is determined with a deadtime by sensing the terminal voltage
as the average value between two firing pulses.
Thus, current actual value oscillations can occur for an EMF angle pre-
control at the current controller.
This can be avoided if a greater value than the actual armature time
constant is configured at input EMF.TA.
The center frequency (60[kHz]) of the V/f converter in the Sitor-converter
has an offset.
The offset frequency for V
d
=0 V is available at connection EMF.YFO.
XFO
-
60[kHz]
-
YFI
EMF.YFO
=
NOTE
Connection EMF.XFO is an initialization connection and is only valid
after a restart \ reset.
EMF.XFO should be determined after replacing the SITOR-converter
and when commissioning the system.
Instructions are provided in the Section: Voltage sensing calibration.
EMF.
Significance
Value\connection
AD
Hardware address
RRV
Sitor rated voltage of the sensing [V].
(e.g. Sitor = 1000[V] PT = 30[kHz] )
Condition: RRV
≥
ARV, otherwise, QSF\bit 14 = 1
(Initialization connection/
default: 0.0)
ARV
Rated system / motor voltage [V]
Condition: RRV
≥
ARV
≠
0, otherwise, QSF\bit 14 = 1
(Initialization connection/
default: 0.0)
NF
Normalization of the voltage actual value at YUA
NF= 1 (YUA = normalized value),
NF= ARV (YUA , YEM = absolute value)
(Initialization connection/
default: 1.0)
Comment
Comment
Calibration
frequency of the V/f
converter
I/O for EMF