B9: Zero Servo - YASKAWA A1000 HHP Programming Manual

1.2 b: Application
Droop control automatically balances the load level between two motors driving the same load. Droop control must be activated
in one of the drives controlling these motors. The drive in which Droop control is activated shifts the load from one motor to
another by automatically reducing the speed when the torque reference rises, and automatically increasing the speed when the
torque reference falls.
Motor A runs faster than B, pulling more load
A
B
Droop Control increases the speed reference in
n b7-01: Droop Control Gain
Sets the amount of speed reduction when the torque reference is 100%. The gain is set as a percentage of the maximum output
frequency. A setting of 0.0% disables the Droop control function.
No.
b7-01
n b7-02: Droop Control Delay Time
Adjusts the responsiveness of Droop control. Reduce the setting if the reaction time is too long, and increase the setting if
hunting occurs.
No.
b7-02
n b7-03: Droop Control Limit Selection
Enables or disables the droop control limit.
No.
b7-03
Setting 0: Disabled
Setting 1: Enabled
u

b9: Zero Servo

The Zero Servo function is a position loop that can be used in CLV and CLV/PM control modes to lock the motor at a certain
position.
44
A
= 100% Load = 90% Load
f = constant
ref_A
f increase
ref_B
B
= 80% Load = 90% Load
drive B accomplishing load balance
Figure 1.25 Droop Control Application
Parameter Name
Droop Control Gain
Speed
0
Figure 1.26 Droop Control Gain
Parameter Name
Droop Control Delay Time
Parameter Name
Droop Control Limit Selection
YASKAWA ELECTRIC SIEP YEAHHP 01B YASKAWA AC Drive – A1000 HHP Programming Manual
Motor B runs faster than A, pulling more load
A
= 80% Load
B
= 100% Load
Droop Control decreases the speed reference in
drive B accomplishing load balance
Speed reference
Droop control gain
b7-01
Torque
100%
A
= 90% Load
f = constant
ref_A
f decrease
ref_B
B
= 90% Load
Setting Range
0.0 to 100.0%
Setting Range
0.03 to 2.00 s
Setting Range
0, 1
Default
0.0%
Default
0.05 s
Default
1