Yaskawa G7 Drive - Manual (Page 239)

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‹ 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 Parameters
* In Flux Vector or in Open Loop Vector 2, the setting range becomes 0 to 2.
Parameter
Number
Name
Description
Setting
Range Factory
Setting
Change
during
Operation
Control Methods
Display V/f
V/f
with
PG
Open
Loop
Vector
1
Flux
Vector
Open
Loop
Vector
2
L3-04
Stall
Prevention
Selection
During
Deceleration When using a braking resistor, use
setting "0". Setting "3" is used in
specific applications.
0: Disabled - The Drive decelerates
at the active deceleration rate. If
the load is too large or the
deceleration time is too short, an
OV fault may occur.
1: General Purpose - The Drive
decelerates at the active
deceleration rate, but if the main
circuit DC bus voltage reaches
the stall prevention level (380/
760Vdc), deceleration will stop.
Deceleration will continue once
the DC bus level drops below the
stall prevention level.
2: Intelligent - The active
deceleration rate is ignored and
the Drive decelerates as fast as
possible w/o hitting OV fault
level. Range: C1-02 / 10.
3: Stall Prevention w/ Braking
Resistor - Stall prevention during
deceleration is enabled in
coordination with dynamic
braking.
0 to 3 * 1 No Q Q Q Q Q
StallP Decel
Sel