A fundamental characteristic of an induction motor is that its rotational speed decreases as the output torque increases. When sensorless vector control is applied, the relationship between torque and speed is significantly improved, allowing the motor to deliver high torque even at low rotational speeds. With sensorless vector control, a starting torque of up to 200% can be achieved at 0.5 Hz. To configure this function, the inverter is equipped with an auto-tuning function (rotation method and stop method) that automatically configures the motor constants.
Before starting the auto-tuning process, ensure that the motor has been configured according to the quick start guide.
M1-ECT Process
Go online with the drive in Sysmac Studio, then right-click the drive and select Setup and Tuning.
Select Motor ParametersAuto Tuning.
For most standard applications using induction motors, select IM Vector Control without speed sensor and click Next. For other motors or control methods, refer to the user’s manual.
Confirm that the motor parameters match the motor nameplate or datasheet, then click Next.
Select the tuning method. In most cases, choose Tune the motor parameters while rotating. If the motor must not rotate, select Tune the motor parameters while stopped. Note that slight motor movement may still occur with the stopped method. Click Start to begin tuning. The motor will run through the tuning process. A dialogue will notify when the auto-tune is completed. Close the dialogue then click Next. The tuning parameters are automatically written to the drive upon completion.
The next screen displays the tuning parameters. If the values are acceptable, select Finish. You may also copy the tuning parameters to another drive by selecting Copy Settings.
M1-STD Process
Part names and Descriptions
Presetting of parameters 1) Set parameter F042 (1st Drive Control Selection) to 5 (IM Vector control without speed sensor). For other motor types or control methods please refer to the users manual. 2) Set parameters the below parameters according to your application and motor nameplate.
Preparing the mechanical system As preparation for performing rotation tuning, remove machine couplings, and disable safety interlocks
Execution of auto-tuning 1) Set parameter P04 to 1 or 2, and press the Enter key. You will see your selection blink slowly. 2) Input the RUN command. In the factory default state, forward rotation is performed when the Run key is pressed in an enabled state. 3) When the RUN command is input, 1, 2 will remain lit and tuning is started. The time required for auto-tuning is approx.1 minute. 5) The tuning is completed when End is displayed. Turn the RUN command OFF. If the RUN command was input via the touch panel or via communication, the RUN command is shut off automatically as soon as tuning is completed. 6) When tuning is completed, the tuning parameters will be automatically written to the drive.
Troubleshooting auto-tuning error codes
As unwanted tuning might cause hunting or other malfunctions or worsen operational accuracy, the inverter generates a tuning error (alarm code: 25 Hex) and discards tuning values when an abnormality is found in the tuning result. When tuning ends in a tuning error (alarm code: 25 Hex), check the following.
Is inverter output wiring open?
Has the mechanical brake operated?
Has the free-run command "FRS" turned ON?
Are parameter settings correct?
Alarm sub codes can be checked by the error sub code (X003). Individual alarms occur in addition to the following alarms when regular alarm detection is activated. The following table summarizes the causes of tuning errors.
Troubleshooting auto-tuning performance
If sensorless vector control does not provide the intended performance characteristics, adjust the motor parameters depending on the phenomenon, as shown in the following table.
