Zero-Servo Function - Omron VARISPEED G7 Instruction Manual

Related Constants
Con-
stant
Number
b7-01
b7-02
Setting Precautions
Droop control is disabled if b7-01 is set to 0.0.
•
Set b7-01 to the amount of slip as the percentage of slip when the maximum output frequency is input and
•
the rated torque is generated.
Constant b7-02 is used to adjust the responsiveness of droop control. Increase this setting if oscillation or
•
hunting occur.
Setting the Droop Control Gain
Set the droop control gain as the speed reduction at a 100% motor torque, as a percentage of the maximum
output frequency.

Zero-servo Function

The zero-servo function holds the motor when the motor is stopped in what is call a zero-servo status. This
function can be used to stop the motor even with an external force acts on the motor or the analog reference
input is offset.
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6
Name
Description
Display
Droop control Sets the slip as a percentage of
gain maximum frequency when the
maximum output frequency is
specified and the rated torque
occurs.
Droop Quantity
Droop-control is not performed
when the setting is 0.0.
Droop control
Droop control responsiveness
delay time
constant
When hunting or oscillation
Droop Delay
occurs, increase the value.
Time
Torque
0
Fig 6.73 Droop Control Gain
Change
Setting Factory during
Range Setting Opera-
tion
0.0 to
0.0 Yes
100.0
0.03 to
0.05 s No
2.00
b7-01
Speed reference
Control Methods
Open
V/f Flux
Loop
V/f with Vec-
Vector
PG tor
1
No No No A
A A A A
100%
Speed
Open
Loop
Vector
2
A
A