
Basic Operation
6.3.2 Setting the Zero-speed Operation Constants
- 26
J
Initial Excitation Settings: b2-01, b2-03, b2-04
D
Set the zero speed level, DC injection braking time at startup, and the DC injection braking time when
stopping.
User
Change
during
Setting
Factory
Valid Access Levels
User
Constant
Number
Name
during
Opera-
tion
Setting
Range
Unit
Factory
Setting
Open Loop
Vector
Flux Vector
b2-01
Zero speed level (DC in-
jection braking starting
frequency)
0.0 to 10.0
Hz
0.5
B
B
b2-03
DC injection braking
time at start
0.00 to
10.00
s
0.00
B
B
b2-04
DC injection braking
time at stop
0.00 to
10.00
s
0.50
B
B
D
With flux vector control, the DC injection braking function is replaced by the initial excitation function
and zero speed function.
D
The timing of the initial excitation function depends on the zero-speed operation method selected in
b1-05 (zero-speed operation), as shown in Figure 6.10.
D
The initial excitation function stops a motor that is rotating because of inertia.
Run command
OFF
ON
Frequency reference
from analog input
0
E1-09
D
b1-05 = 0
(RUN at Frequency
Ref)
Initial
excitation
BB (Baseblock)
BB
D
b1-05 = 1
(STOP)
Initial excitation
from E1-09
D
b1-05 = 2
(RUN at Min Frequency)
D
b1-05 = 3
(RUN at Zero RPM)
Zero speed
BB
BB
BB
BB
BB
BB
Zero speed
Inverter internal frequency reference
(Soft start input)
After the frequency reference
falls below E1-09, initial excita-
tion starts when the motor speed
drops below b2-01.
After the run command goes
OFF, zero-speed control is
performed for the time set in
b2-04 when the motor speed
drops below b2-01.
After the run command goes
OFF, zero-speed control is
performed for the time set in
b2-04 when the motor
speed drops below b2-01.
Initial
excitation
Initial
excitation
After the run command goes
OFF, zero-speed control is per-
formed for the time set in b2-04
when the motor speed drops be-
low b2-01.
Fig
6.10
Settings for Initial Excitation and Zero-speed Control
D
Initial excitation is started from b2-01 (zero speed level) when decelerating. A setting of b2-01 < E1-09
is valid only with flux vector control.
D
The current level for the initial excitation function is set in E2-03 (motor no-load current).
D
The DC injection braking current (b2-02) isn’t used with flux vector control and can’t be set.
6