YASKAWA T1000V Technical Manual page 237

Problem
• Poor motor torque and speed
response
• Control motor hunting and
oscillation at speeds between 10
and 40 Hz.
• Overvoltage trips when
accelerating, decelerating, or
during sudden speed or load
changes.
• Poor motor torque and speed
response
• Motor hunting and oscillation.
• Poor speed response and
stability
• Poor speed precision
• Motor noise
• Control motor hunting and
oscillation occur at speeds below
10 Hz.
• Poor motor torque at low speeds
• Poor speed response
• Motor instability at motor start.
<1> The default value is determined by the control mode (A1-02). The value shown here is the default when using V/f Control.
When using OLV Motor Control, leave the torque compensation gain (C4-01) at its default setting of 1.00. To increase
speed precision during regeneration in OLV Motor Control, enable slip compensation during regeneration (C3-04 = "1").
YASKAWA ELECTRIC SIEP C710606 44B YASKAWA AC Drive T1000V Technical Manual
Parameter No.
• To improve motor torque speed response,
gradually reduce this setting by 10 ms and check
the performance.
• If motor hunting and oscillation occur as a result
AFR Time Constant 1 of load inertia, gradually increase the setting by
(n2-02) 50 ms and check the performance.
Note: Ensure that n2-02 ≤ n2-03. When making
adjustments to n2-02, set C4-02 (Torque
Compensation Primary Delay Time Constant 1)
accordingly.
• If overvoltage trips occur, gradually increase this
setting by 50 ms.
• If response is slow, gradually reduce this setting
AFR Time Constant 2 by 10 ms.
Note: Ensure that n2-02 ≤ n2-03. When making
(n2-03)
adjustments to n2-03, increase the value of C4-06
(Torque Compensation Primary Delay Time 2)
proportionally.
• If overvoltage trips occur, gradually increase this
setting by 10 ms and check the performance.
• If response is slow, gradually reduce this setting
Torque Compensation
by 2 ms and check the performance.
Primary Delay Time
Note: Ensure that C4-02 ≤ C4-06. When changing
Constant 2 (C4-06)
C4-06 (Torque Compensation Primary Delay Time
Constant 2), increase the value of n2-03
proportionally.
• To improve motor torque speed response,
gradually reduce this setting by 2 ms and check
Torque Compensation the performance.
Primary Delay Time • If motor hunting and oscillation occur, gradually
Constant 1 increase this setting by 10 ms.
Note: Ensure that C4-02 ≤ C4-06. When making
(C4-02)
adjustments to C4-02, increase n2-02 (AFR Time
Constant) proportionally.
• If response is slow, gradually decrease the setting
Slip Compensation
by 10 ms.
Primary Delay Time
• If speed is unstable, gradually increase the setting
Constant (C3-02)
by 10 ms.
• If speed is too slow, gradually increase the setting
Slip Compensation by 0.1 ms.
Gain (C3-01) • If speed is too fast, gradually decrease the setting
by 0.1 ms.
• If there is too much motor noise, the carrier
frequency is too high.
• If motor hunting and oscillation occur at low
Carrier Frequency
speeds, reduce the carrier frequency.
Selection (C6-02)
• The default setting for the carrier frequency
depends on the drive capacity (o2-04) and Drive
Duty Selection (C6-01).
• If motor torque and speed response are too slow,
increase the setting.
• If the motor exhibits excessive instability at start-
Mid Output Voltage A
up, reduce the setting.
(E1-08)
Note: The default value is for 200 V class units.
Minimum Output
Double this value when using a 400 V class drive.
Voltage (E1-10)
When working with a relatively light load,
increasing this value too much can create an
excessively high of a torque reference.
6.2 Motor Performance Fine Tuning
Corrective Action
Suggested
Default Value
Setting
50 ms 50 to 2000 ms
750 ms 750 to 2000 ms
150 ms 150 to 750 ms
20 ms 20 to 100 ms
<1>
200 ms 100 to 500 ms
<1>
1.0 0.5 to 1.5
<1>
Determined by
0 to the default
o2-04 and
setting
C6-01
E1-08: 12.0 V
<1>
Initial ±2 V
E1-10: 2.5 V
<1>
6
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