YASKAWA VARISPEED-616G5, Instruction Manual

Page: 172 / 355

Advanced Operation
7.3.1 Droop Control Function
7 - 18
7.3.1 Droop Control Function
Droop control is a function that allows the user to set the amount of motor slip. When a single load is oper-
ated with two motors (such as in a crane conveyor), a high-resistance motor is normally used, as shown
in Figure 7.6.
If droop control is used, a high-resistance motor characteristics can be set for a general-purpose motor.
Also, it is easy to make adjustments while watching the load balance because the amount of slip can be
set arbitrarily.
The balance of the load is very different with different amounts of slip.
Torque
Motor A’s torque
characteristics
Load torque
Motor B’s torque
characteristics
T
A
-T
B
>>0
Reference
speed
Speed
Load balance when using a general-purpose motor
T
A
T
B
Load balance when using a high-resistance motor
Torque
Motor A’s torque characteristics
Load torque
T
A
-T
B 0
Reference
speed
Speed
T
A
T
B
Motor B’s torque characteristics
Fig
7.6
Droop Control Function
J
Droop Control Gain: b7-01
User
Change
during Setting Factory
Valid Access Levels
User
Constant
Number
Name
g
during
Opera-
tion
Setting
Range
Unit Factory
Setting
V/f
Control
V/f with
PG
Open
Loop
Vector
Flux
Vector
b7-01
Droop control gain
f
0.0 to 100.0 % 0.0
× × ×
A
D
Set the amount of slip as the percentage of slip when the maximum output frequency is input and the
rated torque is generated.
D
Droop control is disabled if b7-01 is set to 0.0.
J
Droop Control Delay Time: b7-02
User
Change
during Setting Factory
Valid Access Levels
User
Constant
Number
Name
g
during
Opera-
tion
Setting
Range
Unit Factory
Setting
V/f
Control
V/f with
PG
Open
Loop
Vector
Flux
Vector
b7-02
Droop control delay
time
f
0.03 to 2.00 s 0.05
× × ×
A
D
Constant b7-02 is used to adjust the responsiveness of droop control.
D
Increase this setting if oscillation or hunting occur.
7