YASKAWA V1000 Series Installation & Start-Up Manual page 257

Unexpected Noise from Connected Machinery
Cause
The carrier frequency is at the resonant
frequency of the connected machinery.
The drive output frequency is the same
as the resonant frequency of the
connected machinery.
Oscillation or Hunting
■
Cause
Insufficient tuning in Open Loop Vector
Control.
Auto-Tuning has not yet been performed
(required for Open Loop Vector Control).
Insufficient tuning in Open Loop Vector
Control.
Gain is too low when using PID control.
The frequency reference is assigned to an
external source.
The cable between the drive and motor is
too long.
YASKAWA TM.V1000.01 V1000 Drive Installation & Start-Up Manual (Preliminary 01-19-07)
5.10 Detailed Troubleshooting
Possible Solutions
Adjust the carrier frequency using parameters C6-02 through C6-05.
• Adjust the parameters used for the Jump Frequency function (d3-01
through d3-04) to skip the problem-causing bandwidth.
• Place the motor on a rubber pad to reduce vibration.
Possible Solutions
• Adjust the following parameters in the order listed to get better gain.
• A decrease in gain should be followed with an increase in the primary
delay time constant.
C4-02 (Torque Compensation Primary Delay Time)
n2-01 (Speed Feedback Detection Control [AFR] Time Constant 1)
C3-02 (Slip Compensation Primary Delay Time)
• The response for torque compensation and slip compensation will drop
as the time constant is increased.
• Perform Auto-Tuning.
• Set motor parameters after calculating the proper values.
• Change the motor control method to V/f Control (A1-02 = "0").
• Adjust the following parameters in the order listed to get better gain.
• A decrease in gain should be followed with an increase in the primary
delay time constant.
C4-02 (Torque Compensation Primary Delay Time)
n1-02 (Hunting Prevention Gain Setting)
• The response for torque compensation and slip compensation will drop
as the time constant is increased.
Check the period of oscillation and adjust P, I, and D settings accordingly.
• Ensure that noise is not affecting the signal lines.
• Separate main circuit wiring and control circuit wiring.
• Use twisted-pair cables or shielded wiring for the control circuit.
• Increase the analog input time filter constant (H3-13).
• Perform Auto-Tuning.
• Reduce the length of the cable.
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