Lenze E94P PositionServo with MVOB - Manual (Page 82)

80 L S94H201E_13426446_EN
Operation
Step 2: Fine Tuning the Velocity P-Gain
Slowly alter the Velocity P-Gain (increase and decrease) and observe the motor velocity waveform on the
oscilloscope. As the P-Gain increases the gradient of the velocity during acceleration and deceleration will
also increase as will the final steady state velocity that is achieved. The application of too much P-Gain will
eventually result in an overshoot in the motor velocity, and further increases will result in larger overshooting
to the point that instability (continuous oscillation) occurs.
Increase the velocity P-gain until some overshoot occurs. Some overshoot is generally ok, and the objective
is typically to achieve the shortest possible settle time (steady state velocity). When the system appears
to have reached the shortest possible settle time, with acceptable overshoot, cease from increasing the
P-Gain.
Scope traces will be similar to those shown in Step 1, however the P-gain will now be given a more precise
adjustment in order to obtain the best possible tuning.
Good Fine Tuning of the P-Gain
Small overshoot with excellent settle time and
steady state velocity regulation.
Step 3: Setting the Velocity I-Gain
The purpose of the velocity I-gain is to correct any error that is present between the commanded velocity
and the steady state velocity that could not be rectified by adjustment of the velocity P-gain. Adjustment of
the velocity I-gain can also reduce the steady state ripple that may occur in the velocity waveform. Lastly,
velocity I-gain has a positive effect on the holding torque produced by the motor.
Slowly increase the “Velocity I-Gain” and check for correction of the steady state error in the velocity
waveform. Continuing to increase the velocity I-gain will eventually result in increased overshoot and
instability in the motor velocity waveform. Stop increasing the I-Gain when additional overshoot or instability
starts to occur.
I-Gain set too LOW
Error exists between Commanded steady
state velocity and Actual steady state velocity