Fuji Electric FRENIC-HVAC User Manual page 364

S-curve acceleration/deceleration
To reduce an impact that acceleration/deceleration would make on the machine, the inverter
gradually accelerates or decelerates the motor in both the starting and ending zones of
acceleration or deceleration. Two types of S-curve acceleration/deceleration rates are
available; applying 5% (weak) and 10% (strong) of the maximum frequency to all of the four
inflection zones. The reference acceleration/deceleration time determines the duration of
acceleration/deceleration in the linear period; hence, the actual acceleration/deceleration time
is longer than the reference acceleration/deceleration time.
Starting zone
S-curve (Weak)
S-curve (Strong)
<S-curve acceleration/deceleration (weak): when the frequency change is 10% or more of the
maximum frequency
>
Acceleration or deceleration time (s) = (2 × 5/100 + 90/100+ 2 × 5/100) × (reference
<S-curve acceleration/deceleration (
maximum frequency--10% at the leading edge and 20% at the trailing edge
Acceleration or deceleration time (s) = (2 × 10/100 + 80/100 + 2 × 10/100) × (reference
Acceleration
Ending zone
5% 5%
10% 10%
acceleration or deceleration time)
= 1.1 × (reference acceleration or deceleration time)
): when the frequency change is 20% or more of the
strong
acceleration or deceleration time)
= 1.2 × (reference acceleration or deceleration time)
6-54
Deceleration
Starting zone Ending zone
5% 5%
10% 10%
>