Chapter 6 start and stop control
87
Starting DC braking is only effective when the startup mode is direct startup. At this
time, the inverter first performs DC braking according to the set starting DC braking current,
and then starts running after the DC braking time is started. If the DC braking time is set to 0,
it will start directly without DC braking. The greater the DC braking current, the greater the
braking force.
If the starting mode is asynchronous machine pre-excitation start, the inverter first
establishes the magnetic field according to the preset pre-excitation current, and then starts
running after the set pre-excitation time. If the pre-excitation time is set to 0, it will start
directly without the pre-excitation process.
Start DC braking current / pre-excitation current, which is a percentage of the rated
current of the inverter.
P6-07
Acceleration
and
deceleration
0
：
Linear acceleration and deceleration
1: S curve acceleration and deceleration
A
2: S curve acceleration and deceleration
B
Default
：
0
Select the way the frequency change of the inverter during start and stop.
0: Linear acceleration/deceleration The output frequency is incremented or
decremented by a straight line. Choose from 4 acceleration and deceleration times.
1:S curve acceleration and deceleration A
The output frequency is incremented or decremented according to the S curve. The S-
curve is used in places where gentle start or stop is required, such as elevators,
conveyor belts, etc. The function codes P6-08 and P6-09 respectively define the time
ratio of the start and end segments of the S-curve acceleration/deceleration.
2: S curve acceleration and deceleration B
In the S-curve acceleration/deceleration B, the motor rated frequency fb is always the
inflection point of the S-curve. As shown in Figure 6-12. It is generally used in
applications where fast acceleration and deceleration are required in high-speed areas
above the rated frequency.
When the set frequency is above the rated frequency, the acceleration and deceleration
time is
T
f
f
t
b
9
5
(
9
4
2
)
Where f is the set frequency, the rated frequency of the fb motor, and T is the time from the
0 frequency acceleration to the nominal frequency fb.
P6-08
S curve starting time
ratio
0.0%
～（
100.0%-P6-09
）
Default
：
30.0%
P6-09
S curve end period time
ratio
0.0%
～（
100.0%-P6-08
）
Default
：
30.0%
The function codes P6-08 and P6-09 respectively define the ratio of the initial segment
and the end segment time of the S-curve acceleration/deceleration A. The two function
codes should satisfy: P6-08 + P6-09 ≤ 100.0%.
In Figure 6-11, t1 is the time defined by parameter P6-08, and the slope of the output
frequency change gradually increases during this period. T2 is the time defined by
parameter P6-09, during which the slope of the output frequency change gradually changes
