Page 7.5 - 4 COMBIVERT F5-A, -E, -H © KEB, 2012-10
Motor data and controller adjustments of the asynchronous motor
7.5.1 Open loop operation (V/f characteristic)
7.5.1.1 Rated frequency (uF.00), boost (uF.01) and delta boost (uF.04 / uF.05)
The voltage/frequency characteristic (U/f) is adjusted with the rated frequency (uF.00) and the boost (uF.01).
The rated frequency adjusts the frequency at which 100 % modulation depth (~input voltage) are achieved. The
boost adjusts the output voltage to 0 Hz. Depending on uF.10 the modulation limit can be further increased in
this stage up to 200 % (see Fig.7.5.1.1).
ru.42: modulation grade
Figure 7.5.1.1a Rated frequency and
boost
uF.01
100%
uF.00
110%
200%
uF.10=0
uF.10=1
uF.10=2 / 3
uF.00 = 0,00...400 Hz; Default = 50 Hz
uF.01 = 0,0...25,5 %; Default = LTK*
ru.03: Ac-
tual fre-
quency
* LTK = power circuit-dependent
The delta-boost is a time-limited boost used to overcome large breakaway torques. The delta-boost acts adding
to the boost; but the sum is limited to 25.5 %.
Figure 7.5.1.1b Delta boost ru.42: modulation grade
uF.04 = 0,0...25,5 %; Default = 0 %
uF.05 = 0,00...10,00 s; Default = 0 s
U
A
t
uF.01
100%
uF.05
uF.04
7.5.1.2 Maximal voltage mode (uF.10)
By changing the maximal voltage mode more torque can be released free above the rated frequency through
overmodulation (110% voltage). Raising the v/f-characteristic has an inuence at activated energy saving func-
tion or at voltage stabilisation.