V/F Control - Siemens SINAMICS S120 Function Manual

3.9

V/f control

For V/f control, the drive is operated with an open control loop. In this open-loop control
system, the drive does not require speed feedback and no actual current sensing. Operation
is possible with a small amount of motor data.
With V/f control, the following components and data can be checked:
● Motor Module
● Power cable between the Motor Module and motor
● Motor
● DRIVE-CLiQ cable between the Motor Module and motor
● Encoder and actual encoder value
The following motors can be operated with V/f control:
● Induction motors
● Synchronous motors
Note
In V/f mode, the calculated actual speed value is always displayed in r0063. The speed of
the encoder (if installed) is displayed in r0061. If an encoder is not installed, r0061 displays
"0".
Note
The operation of synchronous motors with V/f control is allowed only at up to 25% of the
rated motor speed.
Structure of V/f control
Figure 3-10
Drive functions
Function Manual, (FH1), 01/2013, 6SL3097-4AB00-0BP3
Structure of V/f control
Servo control
3.9 V/f control
109