Mitsubishi FR-A800

(F) Setting of acceleration/deceleration time and acceleration/deceleration pattern
PARAMETERS
291
5
GROUP
F
S-pattern acceleration/deceleration A (Pr.29 = "1")
• Use this when acceleration/deceleration is required for a short time until a high-speed area equal to or higher than the base
frequency, such as for the main shaft of the machine.
• The acceleration/deceleration pattern has the Pr.3 Base frequency (Pr.84 Rated motor frequency under PM sensorless
vector control) (fb) as the point of inflection in an S-pattern curve, and the acceleration/deceleration time can be set to be
suitable for the motor torque reduction in the constant-power operation range at the base frequency (fb) or more.
• Acceleration/deceleration time calculation method when the set frequency is equal to or higher than the base frequency
• Reference (0 Hz to set frequency) of acceleration/deceleration time when Pr.3 = "60 Hz"
NOTE
• For the acceleration/deceleration time setting of the S-pattern acceleration/deceleration A, set the time to Pr.3 (Pr.84 under
PM sensorless vector control) instead of Pr.20 Acceleration/deceleration reference frequency.
S-pattern acceleration/deceleration B (Pr.29 = "2")
• This is useful for preventing collapsing stacks such as on a conveyor. S-pattern acceleration/deceleration B can reduce the
impact during acceleration/deceleration by accelerating/decelerating while maintaining an S-pattern from the present
frequency (f2) to the target frequency (f1).
Acceleration time t = (4/9)  (T/fb
2
)  f
2
+ (5/9)  T
Where T is the acceleration/deceleration time (s), f is the set frequency (Hz), and fb is the base frequency (rated motor
frequency)
Acceleration/deceleration time
(s)
Set frequency (Hz)
60 120 200 400
5 5 12 27 102
15 15 35 82 305
fb
Output frequency (Hz)
Time
[S-pattern acceleration
/deceleration A]
f1
[S-pattern acceleration
/deceleration B]
f2
Time
Set frequency (Hz)
Output frequency (Hz)