Starting with synchronous motors without encoder feedback (PMVC control)

The synchronous motors are permanent magnet motors.

INFORMATION

Check the operation of encoder-free synchronous motors through a test application. Stable operation in this operating mode cannot be ensured for all application cases.
  1. Connect the motor to the inverter. Adhere to the nominal motor voltage when connecting.
  2. Enter the motor data from the motor nameplate:
    • P1-07 = Internal voltage/no-load voltage [V/min-1] at nominal motor speed
    • P1-08 = Rated current of the motor
    • P1-09 = Rated frequency of the motor
    • P1-10 = Rated speed of the motor
    • P1-14 = 201 (extended parameter menu)
    • P4-01 = 3 (PMVC speed control)
    • P2-24 = PWM frequency (at least 8 – 16 kHz)
  3. Set the maximum speed to the maximum rated motor speed using P1-01 and the minimum speed to a minimum of 10% of the rated motor speed using P1-02.
  4. Set the acceleration and deceleration ramps using P1-03 and P1-04.
  5. Start the "Auto-tune" automatic motor measuring procedure as described in chapter Automatic measuring procedure ("Auto-tune").
  6. Check the magnetizing current (P0-14) at half nominal speed without load.
    • If the value is greater than +0.3 A, the nominal motor voltage P1-07 must be reduced.
    • If the value is smaller than -0.3 A, the nominal motor voltage P1-07 must be increased.
  7. Adjust the stiffness in P7-10 to optimize the control behavior:
    • Increasing P7-10 increases the stiffness of the motor. Decreasing the parameter has the opposite effect.
    • The setting range should be between 8 and 15, but may differ.
  8. To adjust the rotor on enable and to achieve more torque in the lower speed range, set P7-14 and P7-15 to 10% first. Individual adjustment might be necessary. Note that the motor may heat up significantly due to the increased current flow.

In rare cases, it can be helpful to compare the parameters determined in the automatic motor measuring procedure to the parameters of the motor data. Correct them, if necessary. Note that the values may deviate in case of long motor cables.

A new measuring procedure is not necessary.