Lenze i550

10.4.9 Flying restart circuit
The ying restart funcon makes it possible to restart a coasng motor on the y during oper-
aon without speed feedback. Synchronicity between the inverter and the motor is coordina-
ted so that the transion to the rotang drive is eected without jerk at the me of connec-
on.
Precondions
•
Drive systems with speed feedback do not need a ying restart circuit because there is
always a jerk-free synchronisaon to the feedback speed.
•
The ying restart circuit operates safely and reliably in case of drives with high centrifugal
masses. If several motors with dierent centrifugal masses are connected to the inverter,
the ying restart circuit must not be used.
•
The ying restart circuit serves to idenfy rotang eld frequencies of up to maximally
±200 Hz.
•
Especially at high power, very high mass ineras and mains voltages higher than 440 V, a
temporary overvoltage in the DC bus may occur. The use of a brake resistor can prevent
this behaviour. 4Use of a brake resistor ^ 521
Required sengs before the ying restart circuit is used:
1.
The motor data must be set correctly. 4Motor data ^ 50
2.
The sengs for the current controller and the ying restart controller must be adapted to
the motor. The sengs are made automacally if one of the following opmisaons is car-
ried out:
4Select motor from motor catalogue ^ 51
4
Automac motor idencaon (energized) ^ 216
4Automac motor calibraon (non-energized) ^ 218
Details
The inverter determines synchronicity by idenfying the synchronous rotang eld frequency.
The "search" starts in the posive direcon.
Duraon:
•
The ying restart process is determined within approx. 0.5 ... 1.5 seconds.
•
The duraon is inuenced by the start frequency 0x2BA1:001 (P718.01).
Seng the funcon:
1.
As starng performance, set the selecon "Flying restart circuit [2]" in 0x2838:001
(P203.01).
•
Thus, every inverter enable causes a synchronisaon to the rotang or standing drive.
•
Aer the inverter has been enabled, the motor can temporarily start or reverse if
drives with low fricon and low mass inera are used.
•
If the inverter is operated with the default sengs, no further sengs are required for
most applicaons.
2.
If required, adapt the current 0x2BA1:001 (P718.01) and the start frequency 0x2BA1:002
(P718.02) for the ying restart circuit.
•
Seng notes can be found in the "Info" column for the respecve parameter.
For diagnosc purposes, the frequency detected when the motor has been restarted on the
y is displayed in 0x2BA1:008 (P718.08).
Conguring the motor control
V/f characterisc control for asynchronous motor (VFC open loop)
Flying restart circuit
188