Fine-Tuning Closed Loop Vector Control - YASKAWA T1000A Technical Manual

Problem
• Poor motor torque and speed
response
• Motor hunting and oscillation
Poor speed response and stability
Poor speed precision
Poor speed precision during
regenerative operation
• Motor noise
• Motor hunting and oscillation occur
at speeds below 10 Hz
• Poor motor torque at low speeds
• Poor speed response
• Motor instability at start
<1> Default setting value is dependent on parameter A1-02, Control Method Selection, and o2-04, Drive Model Selection.
<2> Default settings change when the Control Method is changed (A1-02).
When using OLV, leave the torque compensation gain (C4-01) at its default setting of 1.00.
u Fine-Tuning Closed Loop Vector Control
Problem
• Poor torque or speed response
• Motor hunting and oscillation
• Poor torque or speed response
• Motor hunting and oscillation
Trouble maintaining the ASR
proportional gain or the integral time at
the low or high end of the speed range
Motor hunting and oscillation
• Motor noise
• Control motor hunting and oscillation
occur at speeds below 3 Hz.
Overshoot or undershoot when the
speed changes with high inertia load.
<1> Refer to C5: Automatic Speed Regulator (ASR) on page 146
YASKAWA ELECTRIC SIEP C710616 30B YASKAWA AC Drive T1000A Technical Manual
Parameter No.
• To improve motor torque speed response, gradually reduce this setting by
2 ms and check the performance.
Torque Compensation Primary • If motor hunting and oscillation occur, gradually increase this setting by
Delay Time Constant 1 (C4-02) 10 ms.
• Note: Ensure that C4-02 ≤ C4-06. When making adjustments to C4-02,
increase the AFR time constant 1 (n2-02) proportionally.
Slip Compensation Primary • If response is slow, gradually decrease the setting by 10 ms.
Delay Time Constant (C3-02) • If speed is unstable, gradually increase the setting by 10 ms.
• If speed is too slow, gradually increase the setting by 0.1 ms.
Slip Compensation Gain (C3-01)
• If speed is too fast, gradually decrease the setting by 0.1 ms.
Slip Compensation Selection Enable slip compensation during regeneration by setting parameter C3-04
During Regeneration (C3-04) = 1.
• If there is too much motor noise, the carrier frequency is too low.
• If motor hunting and oscillation occur at low speeds, reduce the carrier
Carrier Frequency Selection (C6-
frequency.
02)
• Note: The default setting for the carrier frequency depends on the drive
capacity (o2-04) and Duty Selection (C6-01).
• If motor torque and speed response are too slow, increase the setting.
Mid Output Voltage A (E1-08) • If the motor exhibits excessive instability at start-up, reduce the setting.
Minimum Output Voltage (E1- • Note: The default value is for 200 V class units. Double this value when
10) using a 400 V class drive. When working with a relatively light load,
increasing this value too much can result in overtorque.
Table 6.3 Parameters for Fine-Tuning the Performance in CLV
Parameter No.
ASR Proportional Gain 1 • If motor torque and speed response are too slow, gradually increase the
(C5-01) ASR gain setting by 5.
ASR Proportional Gain 2 • If motor hunting and oscillation occur, decrease the setting.
(C5-03) • Parameter C5-03 needs to be adjusted only if C5-05 > 0.
• Perform ASR Auto-Tuning if possible
<1>
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) • Parameter C5-04 needs to be adjusted only if C5-05 > 0.
<1>
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.
<1>
• If motor torque and speed response are too slow, gradually decrease the
ASR Primary Delay Time
setting by 0.01.
Constant (C5-06)
<1>
• If the load is less rigid and subject to oscillation, increase this setting.
• If there is too much motor noise, the carrier frequency is too low.
• If motor hunting and oscillation occur at low speeds, reduce the carrier
Carrier Frequency Selection
frequency.
(C6-02)
• Note: The default setting for the carrier frequency depends on the drive
capacity (o2-04) and Drive Duty Selection (C6-01).
• Enable Feed Forward by setting parameter n5-01 = 1 and perform Inertia
Feed Forward Control (n5-01)
Tuning. If Inertia Tuning is not possible, set parameters C5-17, C5-18,
Inertia Tuning (T1-01 = 8)
and n5-03 manually.
6.2 Motor Performance Fine-Tuning
Corrective Action
Corrective Action
for details on Automatic Speed Regulator (ASR).
Suggested
Default
Setting
20 ms 20 to 100 ms
<1> <1>
200 ms 100 to 500 ms
<2>
1.0 0.5 to 1.5
<2>
0 1
1 (2 kHz) 0 to max. setting
E1-08: 11.0 V
Default setting
<2>
E1-10: 2.0 V ±2 V
<2>
Suggested
Default
Setting
20.00 10.00 to 50.00
0.500 s 0.300 to 1.000 s
0.0 to max output
0.0 Hz
frequency
0.004 s 0.004 to 0.020 s
2.0 kHz to the max.
1
setting
0 1
6
269