Parameters To Minimize Motor Hunting And Oscillation - YASKAWA Z1000 User Manual

Problem Parameter No.
Pull-In Current during
Accel/Decel (n8-51)
DC Injection Braking
Current (b2-02), DC
Oscillation at start or the
Injection Time at Start
motor stalls
(b2-03)
Load Inertia Ratio
(n8-55)
Pull-In Current
Compensation Time
Stalling or oscillation Constant (n8-47)
occur when load is
applied during constant Pull-In Current (n8-48)
speed
Load Inertia Ratio
(n8-55)
Hunting or oscillation Speed feedback
occur Detection Gain (n8-45)
STo fault trips when the Induced Voltage
load is not excessively Constant
high (E5-09 or E5-24)
Stalling or STo occurs at
high speed as the output Output Voltage Limit
voltage becomes (n8-62)
saturated
u

Parameters to Minimize Motor Hunting and Oscillation

In addition to the parameters discussed on pages
oscillation.
Name
(Parameter No.)
Accel/Decel Time
(C1-01 through C1-11)
S-Curve Characteristics
(C2-01 and C2-02)
Jump Frequency
(d3-01 through d3-04)
Analog Filter Time Constant
(H3-13)
Stall Prevention
(L3-01 through L3-06, L3-11)
YASKAWA TOEP YAIZ1U 03B YASKAWA AC Drive – Z1000 User Manual
Increase the pull-in current in n8-51
Use DC Injection Braking at start to align the rotor. This may
cause a short reverse rotation at start.
Increase the load inertia ratio.
Note:
Reduce n8-47 if hunting occurs during constant speed
Increase the pull-in current in n8-48.
Increase the load inertia ratio.
Reduce the speed feedback detection gain in n8-45.
• Check and adjust the induced voltage constant.
• Check the motor nameplate and the data sheet or contact the
motor manufacturer.
Set the value of the input voltage to parameter n8-62
194 and 194, parameters in
Table 5.3 Parameters that Affect Control Performance in Applications
Adjusting accel and decel times will affect the torque presented to the motor during acceleration or deceleration.
Prevents shock at the beginning and end of acceleration and deceleration.
Skips over the resonant frequencies of connected machinery.
Prevents fluctuation in the analog input signal due to noise.
• Prevents motor speed loss and overvoltage when the load is too heavy or during sudden acceleration/
deceleration.
• Adjustment is not normally necessary because Stall Prevention is enabled as a default.
Corrective Action
Setting this value too high can cause
overcompensation and motor oscillation.
Table 5.3
Application
5.2 Motor Performance Fine-Tuning
Default
50%
b2-02 = 50%
b2-03 = 0.00 s
0
5.0 s
30%
0
0.80
Depends on
drive
capacity
600 Vac
(600 V class)
indirectly affect motor hunting and
Suggested
Setting
Increase in steps
of 5%
b2-03 = 0.5 s
Increase b2-02 if
needed
Close to the actual
load inertia ratio
Reduce in
increments
of 0.2 s
Increase in
increments of 5%
Close to the actual
load inertia ratio
Increase in
increments 0.05
Refer to the motor
data sheet or the
nameplate.
Set equal to input
voltage
5
195