Preventing Overvoltage During Deceleration (Stall Prevention During Deceleration Function) - Omron VARISPEED G7 Instruction Manual

Preventing Overvoltage During Deceleration (Stall Prevention During
Deceleration Function)
The Stall Prevention During Deceleration function makes the rate of deceleration more gentle to suppress
increases in DC bus voltage when the DC bus voltage exceeds the set value during motor deceleration.
This function automatically lengthens the deceleration time with respect to the bus voltage, even if the decel-
eration time has been set to a considerably small value.
If L3-04 is set to 1 or 2, when the main circuit DC voltage approaches the stall prevention level during decel-
eration, deceleration stops, and when deceleration falls below the level, is restarted. Using this operation,
deceleration time is automatically lengthened. If L3-04 is set to 1, deceleration time returns to the set value,
and if L3-04 is set to 2, deceleration is automatically adjusted to a faster deceleration time within the range of
the stall prevention level during deceleration.
Related Constants
Con-
stant
Number
L3-04
* The setting range is 0 to 2 for flux vector control and open-loop vector control 2.
-22
6
Name
Description
Display
Stall preven- 0: Disabled (Deceleration as set. If
tion selection deceleration time is too short, a
during decel main circuit overvoltage may
result.)
1: Enabled (Deceleration is
stopped when the main circuit
voltage exceeds the overvoltage
level. Deceleration restarts when
voltage is returned.)
2: Intelligent deceleration mode
(Deceleration rate is
automatically adjusted so that in
StallP Decel
Inverter can decelerate in the
Sel
shortest possible time. Set
deceleration time is
disregarded.)
3: Enabled (with Braking Resistor
Unit)
When a braking option (Braking
Resistor, Braking Resistor Unit,
Braking Unit) is used, always set to
0 or 3.
Change
Setting Factory during
Range Setting Opera-
V/f
tion
*
1 No Q
0 to 3
Control Methods
Open Open
V/f Flux
Loop Loop
with Vec-
Vector Vector
PG tor
1 2
Q Q Q Q