Mitsubishi Electric FR-A700 Instruction Manual page 382

Acceleration and deceleration
Linear acceleration/deceleration (Pr. 29 = 0, initial value)
When the frequency is changed for acceleration, deceleration, etc. in inverter operation, the out-
put frequency is changed linearly (linear acceleration/deceleration) to reach the set frequency
without straining the motor and inverter. Linear acceleration/deceleration has a uniform fre-
quency/time slope (refer to Fig. 6-80).
Hz
fm
S-pattern acceleration/deceleration A (Pr. 29 = 1)
For machine tool spindle applications, etc.
Used when acceleration/deceleration must be made in a short time to a high-speed range of not
lower than base frequency. In this acceleration/deceleration pattern, Pr. 3 Base frequency (fb)
is the inflection point of the S pattern and you can set the acceleration/deceleration time appro-
priate for motor torque reduction in a constant-power operation region of Pr. 3 Base frequency
(refer to Fig. 6-81).
Hz
fm
NOTE As the acceleration/deceleration time of S-pattern acceleration/deceleration A, set the time
taken until Pr. 3 "Base frequency" is reached, not Pr. 20 "Acceleration/deceleration refer-
ence frequency".
6 - 202
linear
Time
S-pattern acceleration/
deceleration A
Time
Fig. 6-80:
Characteristic for parameter 29 = 0
t
Fig. 6-81:
Characteristic for parameter 29 = 1
t
Parameter
I000015C
I000016C