TDE MACNO MINIOPD EXP, User Manual

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2.1.4.2 STEP RESPONSE
Step response is a common mode to test speed loop stability and dynamic performance.
For enable this test set C53=2 (EN_TEST_SPD = 2 Step). In the display appears “Auto”.
At this point all speed reference are ignored, instead a fixed speed reference is calculated equals to
maximum test torque (P130) divided by speed regulator proportional gain. In this way giving this step
speed reference, the torque requested doesn’t go over maximum torque admitted.
Linear ramps are automatically disabled. Giving the run command, motor starts and try to follow the
reference with its dynamic performance.
Evaluating the speed response it’s possible to understand the system stability and speed loop
bandwidth.
With Real Time Graph is possible to see the motor speed response. Set:
Post Trigger Points = 90% Trigger Type = st03 Speed Reference
Trigger level = 1% Trigger slope = ascending
Sample Time = 1
Channels = 2
Channel A = Standard - o03 Reference speed value after ramps
Channel B = Standard - o49 Rotation speed not filtered
Set speed regulator gain and look the step response. Try and repeat until the speed response has
good stability and bandwidth.
Motor runs at constant speed until the run command is on.
Switch off the run command to stop the motor and start a new test.
Step response test is finished only when C53 is manually clear to 0.
2.1.4.2.1 SPEED REGULATOR GAIN SETTING SUGGESTIONS
1. First of all disable integral part setting lead time constant P32 with a big value (>
500ms).
2. Try to find the best proportional gain P31 and filter time constant P33 to obtain a step
response with max overshoot of 20%. It’s important to evaluate also the acoustic and
electrical motor noise.
3. Reduce lead time constant P32 up to minimum value without increase the overshoot