Functions
8.17 Flying restart
Control Units CU240S
Operating Instructions, 11/2006, A5E00766042B AA
8-97
Flying restart without speed encoder
Depending on parameter P1200, after the demagnetization time has expired P0347, flying
restart is started with the maximum search frequency f
search,max
(see figure below).
3
U
3III
VWDQGDUGVOLS
PD[PD[VHDUFK
ຘຘ ຘ
This is realized either after the line supply returns when the automatic restart function has
been activated or after the last shutdown with the OFF2 command (pulse inhibit).
● V/f characteristic (P1300 < 20):
The search frequency is reduced, as a function of the DC link current with the search rate
which is calculated from parameter P1203. In so doing, the parameterizable search
current P1202 is impressed. If the search frequency is close to the rotor frequency, the
DC link current suddenly changes because the flux in the motor establishes itself. Once
this state has been reached, the search frequency is kept constant and the output voltage
is changed to the voltage value of the V/f characteristic with the magnetization time
P0346 (see figure below).
● Closed-loop Vector control without encoder (SLVC):
Starting from the initial value, the search frequency approaches the motor frequency with
the impressed current P1202. The motor frequency has been found if both frequencies
coincide. The search frequency is then kept constant and the flux setpoint is changed to
the rated flux with the magnetization time constant (dependent on P0346).
After the magnetization time P0346 has expired, the ramp-function generator is set to the
speed actual value and the motor is operated with the actual reference frequency.
W
I
I
VHDUFKPD[
6HWSRLQWIUHTXHQF\
'HPDJQHWL]DWLRQ
WLPH
3
)O\LQJUHVWDUW
3
3
0DJQHWL]DWLRQ
WLPH
3
5DPSXS
Figure 8-65 Flying restart
To Next Page
Loading...
Need help?
General
