Best E5 Series User Manual page 95

E5 User Manual
S-curve time at initial segment of Accel is (P12.19●t1) in the figure, in which the Accel rate
increases progressively. In this period, the S-curve time at ending segment is (P12.20●t1) and
the Accel rate decreases gradually. At the middle of t1, it is linear Accel with a constant rate
which is adjusted automatically based on the setting of P12.19 and P12.20.
Decel period t2 is similar as above.
Make sure the sum of proportions of initial and ending segments is no more than 100%, i.e.
the sum of set values of P12.19 and P12.20 should not exceed 100.0%, while that of P12.21
and P12.22 should not exceed 100%.
Example:
Assuming that the maximum frequency P10.08 is 50Hz and the Accel time setting is 6s, the
linear Accel time required for Accel from initial status 10Hz to 40Hz = 6s ● (40Hz-10Hz)/50Hz =
3.6s
Assuming that P12.19 = 20.0% and P12.20 = 30.0%,
Initial segment of Accel S-curve should be 20.0% ● 3.6s = 0.72s; Ending segment of Accel
S-curve should be 30.0% ● 3.6s = 1.08s; linear Accel time at middle segment should be 3.6s -
0.72s - 1.08s = 1.8s.
Difference between S-curve Accel/Decel A and B:
Middle-segment Accel/Decel rate of S-curve Accel/Decel A is determined by the selected
Accel/Decel time 1~4, not subject to the effect of S-curve time span, therefore the total
Accel/Decel time changes with the variation of setting of S-curve time.
When some certain Accel/Decel time is selected for S-curve Accel/Decel B, the total time
of Accel/Decel is constant, but with different proportion of initial part and ending part, the rate of
linear part as well as the shape of S-curve will changes.
4: S-curve Accel/Decel C
The rated frequency of the motor is taken as inflection point of this S-curve, and the set
Accel/Decel time is:
Accel/Decel rate = Motor rated frequency / Accel/Decel time
NOT Accel/Decel rate = Maximum frequency / Accel/Decel time
When command frequency is higher than rated frequency of motor, the Accel/Decel time is
Output frequency
Linear
Accel
Fig.5-11
Chapter 5 Specification of Parameters
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Time
(√)
(●)