KEB COMBIVERT F5-A, Applications Manual, Page: 189 / 552

Motor data and controller adjustments of the asynchronous motor
© KEB, 2012-10 COMBIVERT F5-A, -E, -H Page 7.5 - 27
7
Example:
Calculation of the OC level of the inverter and maximum current (dr.37) if the motor shall be accelerated with
preset torque.
Settings: rated motor current = 30 A
Mmax / Mn = 1.65
Ls (dr.07) = 1.4 mH
Pn = 14.5 kW

P = Pn • 1.65
Inverter with a DC link capacity C = 1780 µF
Parameterizing of the maximum current: Imax (
dr.37) = Mmax/Mn • In_mot = 1.65 • 30 A = 49.5 A
required OC level of the inverter
IRippel = 46.4 / 8 kHz / 1.4 mH • kHz • mH • A = 4.14 A
IRippel_dc = (14.5 kW • 1.65)
2
/ 1780 µF / 1.4 • 105 • µF • mH / kW
2 = 24.1A
OC_Level = (49.5 A +( 25 A + 4.14 A) / √2) • 1.15
OC_Level = 83 A
A 18.F5.H with 8 kHz rated frequency and 90 A OC levels must be selected for this spindle with 30 A rated cur-
rent and 14.5 kW rated power.
Reaching the maximum torque in field weakening operation
The modulation factor must be increased in order to reach this.
The setpoint for the maximum voltage controller is default ds.10 = 97% and can be increased to 100%. 110%
must be adjusted
additionally in ds.04 flux/rotor adaption
mode = on. This is possible from version V.2.1 ASCL,
because the max. modulation factor is always limited to the setpoint in ds.10 + 2% , here 102%.
7.5.2.4 Vector control without speed feedback (ASCL)
This chapter must be read only if an asynchronous motor without speed feedback is to be operated. Since the
speed can be calculated only with the aid of a mathematical model, this operating mode may only be used with
the following limitations:
- Vector control around frequency = 0 is not possible.
- During operation in the low speed range, the motor model may become unstable. Therefore this range
must be left always quickly.
- No safety functions may be derived from the calculated speed
This operating mode is only available through auxilliary software F5H-M.
For the motor model, there are some additional parameter for adapting the encoderless vector control to the
application.
Operation without speed feedback is activated by cS.01 = 2 "calculated actual value".
In parameter
cS.00 "controller configuration", the
value 4 "speed control" or 5 and 6, "torque control", respec-
tively, must be set.