Siemens MICROMASTER 440 - Manual (Page 52)

6 Commissioning Issue 10/06
MICROMASTER 440
52 Operating Instructions (Compact)
Control word of motor model
This parameter controls the operation of the sensorless vector control (SLVC) at very low
frequencies.
This therefore includes the following conditions:
Bit00 Start SLVC open loop 0 NO 1 YES
(Operation directly after an ON command)
Bit01 Zero crossing SLVC open loop 0 NO 1 YES
(zero crossing)
f
t
p1755
Closed loop
Open loop
Start f
t
Closed loop
Open loop
Zero crossing
p1755
p1755
For most applications the setting of parameter p1750 = 0 gives the best result at low
frequency.
Start-freq. motor model (SLVC)
Enter the start frequency of sensorless vector control (SLVC), thereby SLVC switches over
from open-loop to closed-loop at that frequency.
.
.
r0062
Speed
controller
Pre-
control
Torque
limitation
Current
controller
i
sq
−
open/closed
loop
Flux setpoint
closed loop
Flux setpoint
open loop
i
sd
p1610
p1611
−
+
+
0
Act. output
voltage
Act. output
frequency Act. frequency
Current
measurement
Act. angle
Observer model
closed loop
Slip
Frequency
setpoint
i
u
i
w
i
v
p1452 p1470 p1472
p1750/p1755
P1750 = ...
P1755 = ...
1
5.0 Hz