Fine-Tuning Closed Loop Vector Control For Pm Motors; Parameters To Minimize Motor Hunting And Oscillation - YASKAWA T1000A Technical Manual

u Fine-Tuning Closed Loop Vector Control for PM Motors
Problem
• Poor torque or speed response
• Motor hunting and oscillation
• Poor torque or speed response
• Motor hunting and oscillation
ASR proportional gain or the integral
time at the low or high end of the speed
range
Motor hunting and oscillation
Motor stall makes normal operation
impossible
Overshoot or undershoot at speed
changes with high inertia load.
<1> Optimal settings will differ between no-load and loaded operation.
u Parameters to Minimize Motor Hunting and Oscillation
In addition to the parameters discussed on page
hunting and oscillation.
Table 6.7 Parameters that Affect Control Performance in Applications
Name (Parameter No.)
Dwell Function (b6-01 through b6-04)
Accel/Decel Time (C1-01 through C1-11)
S-Curve Characteristics (C2-01 through C2-04)
Analog Filter Time Constant (H3-13)
Stall Prevention (L3-01 through L3-06, L3-11)
Torque Limits (L7-01 through L7-04, L7-06, L7-07)
Feed Forward Control (n5-01 through n5-03)
YASKAWA ELECTRIC SIEP C710616 30B YASKAWA AC Drive T1000A Technical Manual
Table 6.6 Parameters for Fine-Tuning Performance in CLV/PM
Parameter No.
High-speed: ASR Proportional • If motor torque and speed response are too slow, gradually increase the
Gain 1 (C5-01) setting by 5.
Low-speed: ASR Proportional • If motor hunting and oscillation occur, decrease the setting.
Gain 2 (C5-03) • Perform ASR Gain Auto-Tuning if possible
High-speed: ASR Integral Time 1
(C5-02) • If motor torque and speed response are too slow, decrease the setting.
Low-speed: ASR Integral Time 2 • If motor hunting and oscillation occur, increase the setting.
(C5-04)
ASR Gain Switching Frequency Have the drive switch between two different ASR proportional gain and
(C5-07) integral time settings based on the output frequency.
ASR Primary Delay Time
If the load is less rigid and subject to oscillation, increase this setting.
Constant (C5-06)
Motor parameters
Check the motor parameter settings.
(E1- , E5- )
Enable Feed Forward Control by setting parameter n5-01 = 1 and perform
Feed Forward Control (n5-01)
Inertia Auto-Tuning. If Auto-Tuning cannot be performed set parameters
Inertia Auto-Tuning (T2-01 = 8)
C5-17, C5-18 and n5-03 manually.
268
Prevents motor speed loss by maintaining the output frequency when working with heavy loads or when there is powerful
backlash on the machine side.
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.
Prevents fluctuation in the analog input signal due to noise.
• Prevents motor speed loss and overvoltage. Used when the load is too heavy and also during sudden acceleration/
deceleration.
• Adjustment is not normally required because Stall Prevention is enabled as a default. Disable Stall Prevention during
deceleration (L3-04 = "0") when using a braking resistor.
• Sets the maximum torque for Open Loop Vector Control.
• Ensure that the drive capacity is greater than the motor capacity when increasing this setting. Be careful when reducing this
value because motor speed loss may occur with heavy loads.
Used to increase response for acceleration/deceleration or to reduce overshooting when there is low machine rigidity and the
gain of the speed controller (ASR) cannot be increased. The inertia ratio between the load and motor and the acceleration time
of the motor running alone must be set.
6.2 Motor Performance Fine-Tuning
Corrective Action
through 271, the following parameters indirectly affect motor
Application
Suggested
Default
Setting
20.00 10.00 to 50.00
<1>
0.300 to
0.500 s
1.000 s
<1>
0.0% 0.0 to Max r/min
0.004 to
0.016 s
0.020 s
<1>
- -
0 1
6
271