Operating Modes
Parameter manual
b maXX
BM5800
Document No.: 5.16029.03
Baumüller Nürnberg GmbH
628
3.8
3.8.9
Operating Mode U-f Characteristic
The b maXX 5800 drive controller allows the operation of motors according to U-f speci-
fication. Thereby simple applications can be realized at which the motor must be run at a
set speed. No encoder is needed and several motors can be operated at the same con-
verter. For motor protection the U-f operation mode includes an overcurrent protection.
The operation is intended for simple applications with asynchronous motors.
Figure 170:
U-f characteristic
The settings take place in functional block 166. With parameter maximum voltage
(
) and Frequency Umax (
) the slope of the straight line can be param-
eterized. Additionally the voltage is kept constant from the maximum frequency on. Via
the zero voltage (
) a voltage can be set at frequency 0 Hz.
Three different operation modes are possible in general; U/f characteristic with and with-
out overcurrent protection and a operation with the compensating controller for the accel-
eration (see chapter
).At operation without overcurrent protection the controller
is switched off if the maximum current of the converter has been reached, only; at oper-
ation with overcurrent protection the acceleration ramp of the maximum current is
stopped.
Additionally, at all operation modes a slip compensation is possible or an additional speed
controller if an encoder is connected. In
the U/f operation with slip compen-
sation is presented. The speed controller is activated via bit 4 of
so that not the
additional frequency from the slip is added but the output. It reduces the acceleration in-
sofar.
0
20
40
60
80
100
0
20
40
60
80
100
120
140
160
180
200
U
(P166.13)
max
f
(P166.15)
Umax
U (P166.5)
0
V
olt
age
[V]
Frequency [Hz]
