SKS Sweden Bonfiglioli Vectron ACTIVE CUBE ACU 201 Series, Operating Instructions Manual

Page: 206 / 260

204 Operating Instructions ACU 09/08
The set-up of the two current controllers is identical and enables joint setting of am-
plification as well as the integral time for both controllers. For this, the parameters
Amplification
700 and
Integral time
701 are available. The proportional and integra-
tion and component of the current controllers can be switched off by setting the pa-
rameters to zero.
Parameter Settings
No. Description Min. Max. Fact. sett.
700 Amplification 0.00 8.00 0.13
701 Integral time 0.00 ms 10.00 ms 10.00 ms
The guided commissioning has selected the parameters of the current controller in
such a way that they can be used without having to be changed in most applications.
If, in exceptional cases, an optimization of the behavior of the current controller is to
be done, the reference value jump during the flux-formation phase can be used for
this. The reference value of the flux-forming current components leaps to the figure
Current during flux-formation
781 with suitable parameterization and then changes
controlled to the magnetizing current after the expiry of the
Maximum flux-formation
time
780. The operating point necessary for the adjustment demands the setting of
parameter
Minimum Frequency
418 to the value 0.00 Hz, as the drive is accelerated
after magnetizing. The measurement of the step response, which is defined by the
ratio of the currents mentioned, should be done in the motor supply line by means of
a measuring current transformer of a sufficient bandwidth.
Note: The internally calculated actual value for the flux-forming current compo-
nent cannot be output via the analog output for this measurement as the
time resolution of the measurement is not sufficient.
To set the parameters of the PI controller, the
Amplification
700 is increased first
until the actual value overshoots distinctly during the control process. Now, the am-
plification is reduced to about fifty percent again and then the
Integral time
701 is
synchronized until actual value overshoots slightly during the control process.
The settings of the current controllers should not be too dynamic in order to ensure a
sufficient reserve range. The control tends to increased oscillations if the reverse
range is reduced.
The dimensioning of the current controller parameters by calculation of the time con-
stant is to be done for a switching frequency of 2 kHz. For other switching frequen-
cies, the values are adapted internally so that the setting can remain unchanged for
all switching frequencies. The dynamic properties of the current controller improve if
the switching and scanning frequency increases.
The fixed time interval for the modulation results in the following scanning frequen-
cies of the current controller via parameter
Switching frequency
400
.
Settings
Switching frequency Scanning frequency
2 kHz 1) 2 kHz
4 kHz 4 kHz
8 kHz 8 kHz
12 kHz 8 kHz
16 kHz 8 kHz
1)
This switching frequency can be set for parameter
Min. switching frequency
401
.
Operating Instructions ACU 09/08 204