Poor Speed Control Accuracy - YASKAWA V1000 Series Installation & Start-Up Manual

5.9 Troubleshooting without Fault Display
Cause
The Stall Prevention level during run has
been set too low.
Although the drive is operating in Open
Loop Vector motor control method,
Auto-Tuning has not been performed.
Drive reached the limitations of the V/f
motor control method.
Drive Frequency Reference Differs from the Controller Frequency
■
Reference Command
Cause
The analog input frequency gain and bias
are set to incorrect values.
A frequency bias signal is being entered
via analog input terminals A1 or A2.

Poor Speed Control Accuracy

■
Cause
Drive reached the slip compensation
limit.
Motor-rated voltage is set too high in
Open Loop Vector Control.
Auto-Tuning did not complete properly
for Open Loop Vector Control.
234
• Check the Stall Prevention level during run (L3-06).
• If L3-06 is set too low, speed will drop as the drive outputs torque.
• Increase the setting value.
• Perform Auto-Tuning.
• Calculate motor data and reset motor parameters.
• Switch to the V/f motor control method (A1-02 = "0").
• The motor cable may be long enough (over 50 m) to require Auto-
Tuning for line-to-line resistance. Also be aware that V/f Control is
comparatively limited when it comes to producing torque at low speeds.
• Consider switching to Open Loop Vector Control.
• Check the frequency reference terminal input gain level assigned to
terminals A1 and A2, as well as the frequency reference input bias to
terminal A1 and A2 (parameters H3-03, H3-04, and H3-12).
• Set these parameters to the appropriate values.
• If multi-function analog input terminals A1 and A2 are set for frequency
reference (H3-02 = 0 and H3-10 = 0), the addition of both signals builds
the frequency reference.
• Ensure that H3-02 and H3-10 are set appropriately.
• Check the input level set for terminals A1 and A2 (U1-13, U1-14).
• Check the slip compensation limit (C3-03).
• Increase the value set to C3-03.
• The input voltage for the drive determines the maximum output voltage.
A drive with an input of 200 Vac can only output a maximum of 200 Vac.
Open Loop Vector Control sometimes calculates an output voltage
reference value that exceeds the maximum drive output voltage level,
resulting in a loss of speed control accuracy.
• Use a motor with a lower voltage rating (a vector control motor).
• Increase the input power voltage.
• Perform Auto-Tuning again.
YASKAWA ELECTRIC TOEP C710606 09B YASKAWA AC Drive V1000 Installation & Start-Up Manual
Possible Solutions
Possible Solutions
Possible Solutions