KEB COMBIVERT F5 MULTI Applications Manual page 176

Functional Desription
Calculations
Chapter Section Page
6 4 18
Fig. 6.4.9.c Graph with ramp modes
n_soll
f_soll
n_2
f_2
1000 rpm
100 Hz
n_1
f_1
delta_n
delta_f
konstant konstant
The speed change per raster scan delta_t (step size delta_n) for the mode constant
ascent is calculated from the ramp time t_ramp and the reference speed (1000
rpm) as follows:
delta_n=
For different set values the real ramp time is calculated according to following
formula:
t = t_rampe * ó ó ó
The actual step size for the mode constant time is calculated from the step size
delta_n and the actual set value n_set as follows:
delta_n(variable) = delta_n * ó ó ó ó
For a simplification of the internal calculations 1024 min
4096 min dependent on ud.2) are used as reference speed.
-1
delta_n(variable) = delta_n *ó ó ó ó ó
This results in an error of -2.4 % for the real ramp time. If a specific real ramp time
shall be adjusted, the desired value is to be divided by 1.024. Example:
desired ramp time = 10 s
adjsuted ramp time = 10 s / 1.024 = 9.77 s
Date Name: Basis
12.05.04 KEB COMBIVERT F5-M / S
Setpoint- and Ramp Adjustment
delta_n_2
delta_f_2
variabel
variabel
delta_t delta_n
konstant konstant
delta_n
delta_f
konstant konstant
delta_t
delta_t
delta_n_1
delta_f_1
delta_t
variabel variabel
t_1
1000 rpm
ó ó ó ó ó ó ó ó ó
t_rampe / delta_t
n_soll
1000 rpm
n_soll
1000 rpm
n_set
1024 rpm
delta_f
delta_t
t_rampe
(resp. 2048 min
-1
-1
© KEB Antriebstechnik, 2002
All Rights reserved
t_2
t
or
-1