Basic Operation
6.4.2 Setting the Zero-speed Operation Constants
6-32
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
Valid Access Levels
Constant
Number
Name
during
Opera-
tion
Setting
Range
Unit
Factory
Setting
V/f
Control
V/f with
PG
Open
Loop
Vector
Flux
Vector
b2-01
Zero speed level
(DC injection brak-
ing starting frequen-
cy)
×
0.0 to 10.0 Hz 0.5
B B B B
b2-03
DC injection braking
time at start
×
0.00 to
10.00
s 0.00
B B B B
b2-04
DC injection braking
time at stop
×
0.00 to
10.00
s 0.50
B B 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 6.13.
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 speedBB
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 6.13 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