YASKAWA E-S Series Product Manual

Contents

8.8 Manual Tuning8.8.1 Tuning the Servo Gains8-378 TuningGuidelines for Manually Tuning Servo GainsWhen you manually adjust the parameters, make sure that you completely understand theinformation in the user’s manual and use the following conditional expressions as guidelines.The appropriate values of the parameter settings are influenced by the machine specifications,so they cannot be determined universally. When you adjust the parameters, actually operatethe machine and use the SigmaWin+ to monitor operating conditions. Even if the status is sta-ble while the motor is stopped, an unstable condition may occur when an operation referenceis input. Therefore, input operation references and adjust the servo gains as you operate themotor.Stable gain: Settings that provide a good balance between parameters.However, if the load moment of inertia is large and the machine system containselements prone to vibration, you must sometimes use a setting that is somewhathigher to prevent the machine from vibrating.Critical gain: Settings for which the parameters affect each otherDepending on the machine conditions, overshooting and vibration may occur andoperation may not be stable. If the critical gain condition expressions are not met,operation will become more unstable, and there is a risk of abnormal motor shaftvibration and round-trip operation with a large amplitude. Always stay within thecritical gain conditions.If you use the torque reference filter and notch filters together, the interference between the fil-ters and the speed loop gain will be superimposed. Allow leeway in the adjustments.Guidelines are given below for gain settings 1.• Speed Loop Gain (Pn100 [Hz]) and Position Loop Gain (Pn102 [/s])Stable gain: Pn102 [/s] ≤ 2π × Pn100/4 [Hz]Critical gain: Pn102 [/s] < 2π × Pn100 [Hz]• Speed Loop Gain (Pn100 [Hz]) and Speed Loop Integral Time Constant (Pn101 [ms])Stable gain: Pn101 [ms] ≥ 4,000/(2π × Pn100 [Hz])Critical gain: Pn101 [ms] > 1,000/(2π × Pn100 [Hz])• Speed Loop Gain (Pn100 [Hz]) and First Stage First Torque Reference Filter Time Constant(Pn401 [ms])Stable gain: Pn401 [ms] ≤ 1,000/(2π × Pn100 [Hz] × 4)Critical gain: Pn401 [ms] < 1,000/(2π × Pn100 [Hz] × 1)• Speed Loop Gain (Pn100 [Hz]) and First Stage Notch Filter Frequency (Pn409 [Hz]) (or Sec-ond Stage Notch Filter Frequency (Pn40C [Hz]))Critical gain: Pn409 [Hz] > 4 × Pn100 [Hz]• Do not set notch filter frequencies (Pn409 and Pn40C) that are close to the speed loop’sresponse frequency. Set a frequency that is at least four times the speed loop gain (Pn100).(However, Pn103 (Moment of Inertia Ratio) must be set correctly. If the setting is not correct,vibration may occur and the machine may be damaged.• Change the notch filter frequencies (Pn409 and Pn40C) only while the Servomotor is stopped.Vibration may occur if a notch filter frequency is changed during operation.The following adjusted value guidelines require that the setting of Pn103 (Moment of Inertia Ratio)is correctly set for the actual machine.ImportantImportant