Lenze i950

13.4.10 Flying restart circuit
The
"ying restart" funcon serves as a protecve funcon against high compensaon cur-
rents. High compensaon currents can occur in the V/f characterisc control if the drive is not
at standsll at the me the inverter is enabled. The "ying restart" funcon detects the motor
speed by means of a test current and uses this informaon to dene the frequency setpoint.
CAUTION!
If the "ying restart" funcon is
deacvated and the inverter is not enabled at standsll, the
output voltage and the output frequency do not match the current motor speed.
High compensaon currents may ow! First the drive is braked towards 0 Hz to be then accel-
erated again!
▶
Ensure that the drive is at standsll before the inverter is enabled.
Flying restart process
If this funcon is acve, the
ying restart process starts aer the inverter is enabled.
1.
The in
verter reports the started ying restart process to the Controller via bit 8 in the
Lenz
e status word0x2831.
2.
If a speed is found, it is reported to the Controller via bit 9 in the Lenze status word.
3.
The Controller reports to the inverter via bit 0 in the Lenze control word 0x2830 that the
detected speed has been accepted. As long as this is not the case, no further ying restart
pr
ocess is possible.
0x2BA6
0x2831
0x2831
0x2830
Bit 0: Flying restart acknowledge
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OperationEnabled
Bit 8: Flying restart running
Bit 9: Flying restart ready
Found velocity
Parameter seng
The
ying restart algorithm needs a motor voltage as exact as possible. Thus, a
previous detecon of the inverter error characterisc is absolutely necessary.
Compensate inverter inuence to output voltage In addion to the exact motor
voltage, a detailed knowledge of the stator resistance is required. If the ying
restart process does not work as desired, slightly adapt the seng of the stator
resistance in the 0x2C01:002 object. Bit 1 in the Lenze control word 0x2830
serves to block a ying restart process.
The
ying restart process involves a control loop, the controller parameter 0x2BA3 of which
must be adapted to the motor. The automac calculaon is made with the parameter
40x2822:022.
The actual ying restart process can be adjusted via the following parameters:
Conguring the motor control
V
/f characterisc control for asynchronous motor (VFC open loop)
Flying restart circuit
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