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Post by clyevo on Aug 30, 2015 17:24:55 GMT
1) if i auto tune and select option 1 - rotation autotune, is gearbox considered a load? do i need to disconnect motor from gearbox?
2) my inverter output 220v triple phase 50hz my motor only has nameplate with parameter for Y (star/wye) connection: motor rated power 1.5kw motor rated frequency 50hz motor rated speed 1400rpm motor rated voltage 380v motor rated current 3.7A
the motor supplier said i may use delta connection for 220 +-10% how do i input the parameters for auto tune if i use delta connection? do i use the same parameter for star connection as displayed on the nameplate of the motor or do i have to try convert it to this : motor rated voltage 220v motor rated current 6.4A (6.390909090909091)
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Post by Mitch on Aug 31, 2015 18:24:10 GMT
I know you're using different inverter but this might help with question #1- in the WJ200 manual is says this:
"During auto-tuning, insufficient torque may cause a problem in the load (for example, a lift may slide down). In this case, remove the motor from the machine or other load, and perform auto-tuning with the motor alone. The measured inertia J is based on the motor alone. To apply the data, add the moment of inertia of the load machine to the measured J data after converting the moment of inertia to the motor shaft data."
I did a no-rotation autotune. My interpretation of this is (and I could be wrong) it would be fine to keep the gearbox connected as autotune would include the moment of inertia for the gearbox, but if you removed the gearbox you would manually have to add the moment of inertia for gearbox to motor moment of inertia.
(I should note that I'm having over current issues which may or may not be related - discussed in another thread)
It might be interesting to do a comparison of motor constants with a no rotation auto tune, rotation w/gearbox auto tune, and a motor only rotation autotune. If I do this I will post the results.
-Mitch
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Post by clyevo on Sept 1, 2015 1:15:16 GMT
I know you're using different inverter but this might help with question #1- in the WJ200 manual is says this: "During auto-tuning, insufficient torque may cause a problem in the load (for example, a lift may slide down). In this case, remove the motor from the machine or other load, and perform auto-tuning with the motor alone. The measured inertia J is based on the motor alone. To apply the data, add the moment of inertia of the load machine to the measured J data after converting the moment of inertia to the motor shaft data." I did a no-rotation autotune. My interpretation of this is (and I could be wrong) it would be fine to keep the gearbox connected as autotune would include the moment of inertia for the gearbox, but if you removed the gearbox you would manually have to add the moment of inertia for gearbox to motor moment of inertia. (I should note that I'm having over current issues which may or may not be related - discussed in another thread) It might be interesting to do a comparison of motor constants with a no rotation auto tune, rotation w/gearbox auto tune, and a motor only rotation autotune. If I do this I will post the results. -Mitch If you say your inverter need motor inertia + load inertia wouldn't it meant the whole load inertia including your platform as the load?? There is multiple motor that are moving the inertia of the load of your platform. If so, then the load inertia will vary according to position of your platform. My inverter manual did not mention anything about inertia but i am sure one of the parameter has something equivalent to that but not sure which (probably motor current without load). It does mention that static auto-tuning would not be able to calculate mutual inductance and current without load. However I am not sure the significance of those two parameters in relation to accuracy of the inverter to control the motor. This is the calculation for auto-tuning : The f2.08 and f2.09 are ratios Actually it such a hassle to disconnect the motor from gearbox If you say wj200 need rotation autotune to calculate motor inertia (i think equivalent to my inverter "motor currrent without load"), it might be very possible that this will have an effect on the overcurrent protection and acc/dec errors.
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Post by clyevo on Sept 2, 2015 7:48:33 GMT
1) Anyway i contacted the inverter supplier he said it is allright to leave the load on during rotation autotune as long as it doesnt damage the application. Did not give any explanation, but i still think the parameter "motor current without load" would be different with and without load. Still doesn't make sense to me why it should be ok to leave load on.
2) I am now convince that the parameter voltage is based on the inverter output voltage which is 220V that i wired in delta connection. So the motor rated current derived based on 380V*3.7A/220V = 6.4A. This is what i set into the inverter for auto tune.
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Post by riton39 on Sept 2, 2015 8:30:41 GMT
I'm not sure to understand everything. autotune is made without charge right? I think 3-phase 220V each.
F2.10: motor current without load; then motor auto-tuning is finished
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Post by clyevo on Sept 2, 2015 11:18:26 GMT
I'm not sure to understand everything. autotune is made without charge right? I think 3-phase 220V each. F2.10: motor current without load; then motor auto-tuning is finished u need to rephrase this and retranslate, i don understand what u meant
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Post by riton39 on Sept 2, 2015 11:44:18 GMT
autotune is do/made without load right?
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Post by clyevo on Sept 2, 2015 12:00:36 GMT
autotune is do/made without load right? i am not sure if autotune with motion can be made with load or not unless someone can tell me the purpose of "motor current without load" i think autotune with motion should be made without gearbox or load because the parameter generated is "motor current without load" which i dont know the significance some people say it can be made without load because probably that parameter if higher than what it suppose to be is still ok
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Post by Mitch on Sept 3, 2015 7:02:53 GMT
Full disclosure: I'm speculating.
I would imagine that if you're trying to start (or stop) a motor with a load attached to it, it's going to require much more current and torque to overcome the inertia. If there is a load on the motor when the VFD is autodetecting the current required for the motor alone (to stop or start), it would set it too high. In our case, if this is true, I don't think the drag of an unloaded gearbox alone is considered a significant enough load to be an issue.
Is this why you're interested to see the H033 value on the hitachi? I plan to run auto tune this weekend on the motors, and if I happen to remove the motor from gearbox - I'll be sure to record H033 values with and without gearbox for discussion.
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Post by clyevo on Sept 3, 2015 8:55:20 GMT
Full disclosure: I'm speculating. I would imagine that if you're trying to start (or stop) a motor with a load attached to it, it's going to require much more current and torque to overcome the inertia. If there is a load on the motor when the VFD is autodetecting the current required for the motor alone (to stop or start), it would set it too high. In our case, if this is true, I don't think the drag of an unloaded gearbox alone is considered a significant enough load to be an issue. Is this why you're interested to see the H033 value on the hitachi? I plan to run auto tune this weekend on the motors, and if I happen to remove the motor from gearbox - I'll be sure to record H033 values with and without gearbox for discussion. Actually i have tried the autotune without motors and based on statistic there is no difference in parameter "motor current without load" and parameter "rotor mutual inductance". I've tried numerous times and the results varies the same amount between tries with gearbox and lever without the arm or load and without the gearbox. Some tries i notice without gearbox has higher calculation of "motor current without load" than connected to gearbox and lever without the arm or load. For eg: 4.03A vs 3.85A respectively. But i tried this only on one motor. And interestingly i also learn from your manual while figuring your problems in the other thread; that inertia J which is generated in your WJ200 rotation autotune is actually used in your WJ200 to calculate Kp and Ki parameter. This is called inertia auto-tuning. Some inverter have this as separate function then normal autotune. My inverter has this parameter Kp and Ki but there is no auto-tuning for it. Thus i have to tune it manually and set it based on my load. Since there is no exact way to calculate Kp and Ki accurately, i will try tune it based on observation. If too much oscillation reduce Kp and increase Ki or the other way if not much.
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