5.2 b: ApplicationYASKAWA ELECTRIC SIEP C710616 27G YASKAWA AC Drive A1000 Technical Manual 181Parameter Details5 b8-17: Energy Saving Parameter (Kt) for PM MotorsCoefficient to adjust torque linearity.This parameter rarely needs to be changed.When E5-01 (Motor Code Selection (for PM Motors)) is set to 1 or 2, the automatically calculated valuewill be set. This set value cannot be changed. If oscillation occurs when Energy Saving is enabled (b8-01 = 1), then checkthe value displayed in monitor U5-22. If the value displayed differs from the Kt value written on the motor nameplate,then set b8-17 accordingly. b8-27: q-Axis Current Compensation Method when Output Voltage is LimitedThere is normally no need to change this parameter from the default value. Sets a compensation method for the q-Axiscurrent when output voltage is limited.Note: This parameter is not available in models CIMR-A4A0930 and 4A1200.Setting 0: Output Voltage Limit PrioritySetting 1: q-Axis Current Priority b9: Zero ServoThe Zero Servo function is a position loop that can be used to lock the motor at a certain position against external powerto the motor.It must be activated using a digital input set for H1- = 72. The drive will enter Zero Servo mode and maintain thecurrent position when the input closes and motor speed falls below the level set in b2-01. Even if the motor speedexceeds the level set in parameter b2-01 in Zero Servo mode, the drive will continue to maintain the current position. Thedrive accelerates when the input assigned to trigger the Zero Servo function is released and the Run command is stillpresent according to the speed reference.Figure 5.32Figure 5.32 Zero Servo OperationWhen Zero Servo is active, the deviation between the rotor position and the zero position is displayed in monitor U6-22(monitor value must be divided by 4 to get the deviation in actual encoder pulses).A digital output programmed for “Zero Servo complete” (H2- = 33) is turned on when the rotor position is within thezero position, plus or minus the Zero Servo completion width set in parameter b9-02.Note: 1. The Run command must remain on when using the Zero Servo function. If the Run command is switched off, then Zero Servo will nolonger be able to hold the load in place.2. When the Zero Servo command has shut off, the Zero Servo Completion digital output width also shuts off.3. Avoid using Zero Servo to lock 100% load for long periods, as this can trigger a fault. If such loads need to be held in place for longperiods, either make sure the current is less than 50% of the drive rated current during Zero Servo, or use a larger capacity drive.4. If the load rotates the motor when using CLV/PM, a dv4 fault may occur. To prevent this, either increase the Zero Servo gain (b9-01)or increase the number of pulses set to F1-19 that are required to trigger dv4.No. Name Setting Range Defaultb8-17<1> The setting range of the drives is 0.00 to 2.00 for software versions S1018 and earlier.<2> The setting range is 0.00 to 2.00 for models CIMR-A4A0930 to 4A1200.Energy Saving Parameter (Kt) for PM Motors 0.00 to 3.00 <1> <2> 1.00No. Name Setting Range Defaultb8-27 q-Axis Current Compensation Methodwhen Output Voltage is Limited 0, 1 0ONON OFFOFFRun commandZero Servo commandMotor SpeedZero ServoOperationb2-01DC Injection Brakingstart frequencyDecrease the speedreference
