KEB COMBIVERT F5 BASIC - Page 167

6
417
KEB COMBIVERT F5-G / B
Name: Basis
06.02.02
6
© KEB Antriebstechnik, 2002
All rights reserved
Functional DescriptionSet Value and Ramp Adjustment
Section PageDate Chapter
The frequency change per raster scan delta_t (step size delta_f) for the mode
constant ascent is calculated from the ramp time t_ramp and the reference frequency
(100 Hz dependend on ud.2) as follows:
100 Hz
delta_f = —————————
t_rampe / delta_t
For different set values the real ramp time is calculated according to following
formula:
f_set
t = t_ramp * ————
100 Hz
The actual step size for the mode constant time is calculated from the step size
delta_f and the actual set value f_set as follows:
f_set
delta_f(variabel) = delta_f * ———
100 Hz
For the simplification of the internal calculation as frequency reference 102.4 Hz
(e.g. 204.8 Hz or 409.6 Hz dependend on ud.2) is used :
f_set
delta_f(variabel) = delta_f * —————
102.4 Hz
As a result an error of -2,4 % for the real ramp time occurs. If a certain real ramp
time has to be adjusted, the desired value must be divided by 1.024.
Example:
desired ramp time = 10 s
adjusted ramp time = 10 s / 1.024 = 9.77 s
Fig. 6.4.9.c Graph with ramp modes
delta_f
konstant
delta_t
delta_f
konstant
delta_t
delta_f
konstant
delta_t
delta_f_2
variabel
delta_t
delta_f_1
variabel
delta_t
t_ram
p
et_1
f_1
t
t_2
f_2
f_soll
100 Hz
f_soll
f_2
100 Hz
f_1
delta_f
konstant
delta_f
konstant
delta_f_2
variabel
delta_f_1
variabel
delta_f
konstant
Calculations