LS ELECTRIC L7NHF Series, User Manual

Page: 130 / 409

5. Drive Application Functions
5-22
5.4
Velocity Control Settings
5.4.1
Smooth Acceleration and Deceleration
For smoother acceleration and deceleration during velocity control, you can generate an
acceleration/deceleration profile of a trapezoidal or S-curved shape. Here, You can enable S-curve
operation by setting the speed command S-curve time to 1 [ms] or higher.
The velocity command acceleration/deceleration time (0x2301, 0x2302) is the time needed to
accelerate the drive from the zero speed to the rated speed or to decelerate it from the rated speed to
the zero speed.
Speed
Time
Rated Motor
Speed
Speed command
acceleration time
(0x2301)
Speed command
deceleration time
(0x2302)
You can calculate the actual acceleration/deceleration time as below.
Acceleration time= speed command/rated speed x speed command acceleration time (0x2301)
Deceleration time= speed command/rated speed x speed command deceleration time (0x2302)
As shown in the figure below, you can generate an S-curve shape acceleration/deceleration profile by
setting the speed command S-curve time (0x2303) to 1 or a higher value. Make sure to verify the
relationship between the acceleration/deceleration time and S-curve time.
Speed
Time
Speed
Command
Speed command S-curve
time (0x2303)
Speed command S-curve
time (0x2303)
Acceler
ation
Time
Deceler
ation
Time