Feed forward control increases the responsiveness of acceleration and deceleration as specified by the speed reference.

Increase the values set in C5-01 and C5-03 [ASR Proportional Gain] to apply feed forward control to machines that have low rigidity and are possible to have hunting and vibration or to machines that have a large quantity of inertia. When you use this function in CLV control, it also helps prevent overshoot. Refer to Figure 1 for information. Refer to Figure 2 for more information about parameters related to feed forward control.

Set A1-02 [Control Method Selection] to one of these values to enable feed forward control:

  • 3: Closed Loop Vector Control

  • 4: Advanced OpenLoop Vector Control

  • 6: PM Advanced Open Loop Vector

  • 7: PM Closed Loop Vector Control

Note:

  • You cannot use feed forward control to increase responsiveness in applications where you apply loads externally during run at constant speed.

  • When you use the Droop control function, set n5-01 = 0 [Feed Forward Control Selection = Disabled].

  • You cannot use feed forward control with motor 2.

Figure 1. Suppress Overshooting with Feed Forward Control
Figure 2. Configure Feed Forward Control

Before You Use Feed Forward Control

Do one of these procedures before you use feed forward control.

  • Run Auto-Tuning to set motor parameters.

    When you cannot do Auto-Tuning, manually set motor parameters with the information on the motor nameplate or test reports. Set the E2 parameters for induction motors. Set the E5 parameters for PM motors.

  • Set C5 parameters [Automatic Speed Regulator (ASR)] individually to adjust the speed control loop (ASR).

  • If you can connect a motor to a machine and rotate it during Auto-Tuning, do Inertia Tuning.

    The drive automatically adjusts feed forward parameters during Inertia Tuning.

  • If you cannot do Inertia Tuning, refer to Figure 2 and set the parameters related to feed forward control individually.