Lenze i550

10.5 V/f characterisc control for asynchronous motor (VFC closed loop)
The V/f characterisc control with feedback (VFC closed loop) can be used if an asynchronous
motor with motor encoder is connected to the inverter.
The speed feedback leads to the following advantages:
•
Staonary speed accuracy
•
Improved dynamics compared to the V/f characterisc control without feedback (VFC
open loop) and to the encoderless vector control (SLVC)
•
Suitability for group drives
Precondions
•
The V/f characterisc control (VFC closed loop) is only suitable for asynchronous motors.
•
The V/f characterisc control (VFC closed loop) requires a feedback of the speed. A motor
encoder must be connected to the inverter and set as feedback system for the motor con-
trol.
•
This seng is not made automacally if a motor is selected from the motor catalog.
•
For required sengs see chapter "HTL encoder". ^ 162
•
If you actuate a drive with a square-law V/f characterisc: check whether the correspond-
ing drive is suitable for operaon with a square-law V/f characterisc!
•
From the motor nameplate data, at least the rated speed and rated frequency must be
entered, so that the inverter can calculate the correct number of pole pairs. 4Motor
data^ 50
NOTICE
Motor damage!
Operang the motor above the rated motor frequency/rated voltage will lead to damage to
the motor.
▶
Only operate above the rated motor frequency / rated voltage with the permission of the
motor manufacturer.
Details
•
0x2B00 (P302.00) provides dierent characterisc shapes.
•
Liming factors for the V/f characterisc are the rated mains voltage 0x2540:001
(P208.01), the minimum frequency 0x2915 (P210.00) and the maximum frequency
0x2916 (P211.00).
•
The slip compensaon is deacvated in this motor control type. In case of V/f characteris-
c control with feedback, the slip is calculated and injected by the slip controller. 4Slip
controller ^ 227
•
For more details, see the descripon of the motor control type "V/f characterisc control
for asynchronous motor (VFC open loop)". ^ 176
Conguring the motor control
V/f characterisc control for asynchronous motor (VFC closed loop)
192