V/F Control With Parabolic Characteristic; Additional Characteristics For The V/F Control - Siemens SINAMICS G120 Operating Instructions Manual

5.7.1.3

V/f control with parabolic characteristic

Note
V/f control with a parabolic characteristic must not be used in applications in which a high
torque is required at low speeds.
Table 5- 32
Parameter
P0003 = 2
P1300 = 2
5.7.1.4

Additional characteristics for the V/f control

In addition to linear and square-law characteristics, there are the following additional
versions of the V/f control that are suitable for special applications.
Table 5- 33
Parameter
value
P1300 = 1
P1300 = 3
P1300 = 5
P1300 = 6
P1300 = 19
For more information about this function, see function diagrams 6100 and 6200 in the List
Manual.
CU240S and CU240E Control Units, FW 3.2
Operating Instructions, 03/2009, A5E02440075B AA
Setting the control type
Description
Extended access
Control type: V/f control with parabolic characteristic
Further V/f control methods (P1300)
Application
Linear V/f characteristic with Flux Current Control (FCC)
Voltage losses across the stator resistance are automatically compensated. This is
particularly useful for small motors since they have a relatively high stator
resistance. The prerequisite is that the value of the stator resistance in P350 is
parameterized as accurately as possible.
Freely adjustable V/f characteristic,
which supports the torque behavior of
synchronous motors (SIEMOSYN
motors)
Linear V/f characteristic for textile applications where it is important that the motor
speed is kept constant under all circumstances. This setting has the following
effects:
1. When the maximum current limit is reached, the stator voltage is reduced but
not the speed.
2. Slip compensation is locked.
V/f control without characteristic. The interrelationship between the frequency and
voltage is not calculated in the inverter, but is specified by the user. With BICO
technology, P1330 defines the interface via which the voltage setpoint is entered
(e.g. analog input → P1330 = 755).
Functions
5.7 Closed-loop control
111