Motor data and controller adjustments of the asynchronous motor
© KEB, 2012-10 COMBIVERT F5-A, -E, -H Page 7.5 - 23
7
higher. Thereby this can lead to problems during magnetizing at some motor/inverter combinations. In these
cases, the setting dS.04 Bit 5, 6 = 64 "ux controller not active during boot" must be chosen.
7.5.2.3.3.1 Dead time compensation
The drive has also measured the dead time compensation characteristic during automatic identication. The
calibrated characteristic must be activated for the control with motor model by the setting "dead time compen-
sation mode" (uF.18) = 3: „automatic“. „automatisch“ aktiviert werden.
uF.18 Dead time compensation mode
Value Explanation
0: off Deactivates the dead time compensation
1: linear Default setting for u/F characteristics open loop operation
2: e function Only required for special applications
3: automatical-
ly
Activation of the identied characteristic. Shall always be used at control of asynchronous
motors with motor model
Further available kinds of the dead time compensation are only required for special applications (applications
with high frequencies, some special motors) or in other operating modes (e.g. V/f characteristics controlled).
The dead time compensation can be switched off via a digital input. The digital input is selected with parameter
uF.21. This disconnection is only required for special applications with high frequency.
7.5.2.3.4 Magnetisation current adaption / with motor model
For large motors, the automatic calculation of the magnetising current occasionally returns values that are too
large. This way, the dynamic operation in the eld weakening range may worsen.
Whether the automatically calculated magnetising current is too large, can be tested by accelerating the drive to
the eld weakening speed (dr.18) with no load. At this speed, the voltage limit (modulation factor 100%) should
not be reached yet. Othwise the „factor ux adaption“ (dr.19) should be reduced until the modulation factor is
approx. 90 - 95%.
Subsequently, a new identication of the main inductance must be carried out (dr.48 = 6) and the controller
must be adapted to the new main inductance.with dr.48 = 5.
The new "factor ux adaption" must then be checked with a new ramp-up.
Attention: If the factor is reduced too much, the available voltage will not be fully exploited anymore (modulation
factor ru.42 even for high speed and a load always smaller than 95%), and the motor current increases!
7.5.2.3.5 Special functions
7.5.2.3.5.1 High frequency spindle
A special start-up must be executed for motors with output frequencies > 200 Hz.
Rating plate data „rated speed“
The rated speed is not be indicated on the type plate of the spindles. When driving with motor model this rated
speed ist only important for calculation of the pole-pair number and the model tripping level in parameter ds.19
(default value, 2*slip speed).
If no value is indicated here, then 98.5% of the synchronous speed can be accepted.
nn = fn * 60 * 0,985 / ppn
ppn = pole-pair number
To Next Page
Loading...
Need help?
General
