Output Frequency Is Not As High As Frequency Reference - YASKAWA CR700 Technical Manual

3.11 Problems that Can Frequently Occur during Setup and Possible Solutions
Causes
The load is too heavy.
The frequency reference is low.
Incorrect frequency reference setting.
Motor characteristics and drive parameter settings are incompatible with one
another.
Although the drive is operating in vector control mode, Auto-Tuning has not
been performed.
The speed estimation response is too slow when A1-02 = 4 [Control Method
Selection = Advanced Open Loop Vector].
The Stall Prevention level during acceleration set too low.
The Stall Prevention level during run has been set too low.
Drive reached the limitations of the V/f control.

Output Frequency Is Not As High As Frequency Reference

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Causes
Frequency reference is set within the range of the Jump frequency.
Upper limit for the frequency reference has been exceeded.
Large load triggered Stall Prevention function during acceleration.
L3-01 = 3 [Stall Prevention during Accel = Current Limit Method] has been
set.
The motor is rotating at the following speed:
b2-01 [DC Injection/Zero SpeedThreshold] ≤ Motor Speed < E1-09
[Minimum Output Frequency]
230
Possible Solutions
• Increase the acceleration time.
• Check if the mechanical brake is fully releasing as it should.
• Decrease the load so that the output current remains within the motor rated current.
• Use a larger motor.
Note:
• In extruder and mixer applications, the load will sometimes increase as the temperature
drops.
• Although the drive has a Stall Prevention function and a Torque Compensation Limit
function, accelerating too quickly or trying to drive an excessively large load can exceed the
capabilities of the motor.
• Check E1-04 [Maximum Output Frequency] and increase the setting if it is set too low.
• Check U1-01 [Frequency Reference] for proper frequency reference.
• Check if a frequency reference signal switch has been set to one of the multi-function input
terminals.
• Check for low gain level set to H3-03, H3-11, H3-07 [Terminal A1, A2, A3 Gain Setting].
If H3-02, H3-10, H3-06 = 1 [MFAI Function Selection = Frequency Reference] has been set,
check whether voltage (current) has been set.
• Check the values set in H3-02, H3-10, and H3-06.
• Check if the analog input values set to terminals A1, A2, and A3 are appropriate using U1-13
to U1-15 [Terminal A1, A2, A3 Level].
• Set the correct V/f pattern so that hit matches the characteristics of the motor being used.
• Check the V/f pattern set to E1-03 [V/f Pattern Selection].
• Perform Rotational Auto-Tuning.
• Perform Auto-Tuning.
• Calculate motor data and reset motor parameters.
• Switch to A1-02 = 0 [Control Method Selection = V/f Control].
Increase the value set in n4-65 [Flux Estimate Response@High Freq] in increments of 0.1.
Increase the value set in L3-02 [Stall Prevent Level during Accel].
Note:
If L3-02 is set too low, acceleration may be taking too long.
Increase the value set in L3-06 [Stall Prevent Level during Run].
Note:
If L3-06 is set too low, speed will drop as the drive outputs torque.
• The motor cable may be long enough (over 50 m) to require Auto-Tuning for line-to-line
resistance.
• Change the V/f pattern to "High Starting Torque".
• Consider switching to vector control mode.
Note:
Be aware that V/f Control is comparatively limited when it comes to producing torque at low
speeds.
Possible Solutions
Adjust d3-01 to d3-03 [Jump Frequency 1 to 3] and d3-04 [Jump Frequency Width].
Note:
Enabling the Jump frequency prevents the drive from outputting the frequencies specified in
the Jump range.
Set E1-04 [Maximum Output Frequency] and d2-01 [Frequency Reference Upper Limit] to
optimal values.
Note:
Use the following formula to calculate the upper value for the output frequency:
E1-04 × d2-01 / 100
• Decrease the load.
• Adjust L3-02 [Stall Prevent Level during Accel].
1. Check whether the V/f pattern and motor parameter settings are appropriate, and set them
correctly.
2. If this does not solve the problem, and it is not necessary to limit the current level of stall
during acceleration, adjust L3-02.
If this does not solve the problem, set L3-01 = 1 [Enabled].
3.
Set the value of E1-09 lower than the value of b2-01.
YASKAWA SIEPC71061723A YASKAWA AC Drive CR700 Technical Manual