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TMS320F28069M: Instaspin-MOTION motor doesn`t acc slowly

Pavlin Stoyanoff
Expert 1655 points
Part Number: TMS320F28069M
Other Parts Discussed in Thread: MOTORWARE

Greetings! I am using lab06b as a reference and I am trying to make a simple velocity plan. The problem is that my motor ACIM (sensorless control) doesn`t acc slowly but it jumps. For example my values are as it follows:

STVELPLAN_addCfgState(stObj->velPlanHandle,            0, 100L); // State A
STVELPLAN_addCfgState(stObj->velPlanHandle, _IQ24(0.3), 2000L); // State B
STVELPLAN_addCfgState(stObj->velPlanHandle, _IQ24(0.5), 2000L); // State C

When I run the motor manually it can turn on 0.3 and it reaches max speed at 0.5. But when I execute this plan it runs very slowly and when it reaches state C it just jumps to max rpms. I tried differet values for AccLim and jrklim. But for now with no success. I want to make my motor accelerating slowly from 0 to 0.3 and from 0.3 to 0.5. Slow light start (for 2s from 0 to 0.3 with constant acc) and then slow and slow light stop. I `ve noticed that my motor is spinning slowly even when refspeed_krpm is set to 0. I think the default curve is ST curve for lab06b. Should I change the curve. The datasheed says it is the smoothest curve...

How should I achieve that? Or may be I should change the USER_SYSTEM_BANDWIDTH? it is 20 now. 

I think because the motor is not standing still at 0 speed this cause disturbence when the plan starts!

THanks!

  • 0
    TI__Guru** 114200 points

    1. Did you use lab02b and lab-5c to identify the motor parameters and inertia for lab06b?

    2. The sensorless InstaSPIN-Motion is difficult to run the motor at zero speed and very low speed. If you need, you should use the sensor based InstaSPIN-Motion.

  • 0 in reply to Yanming Luo
    Expert 1655 points

    Yes! I have identified the motor parameters, inertia and friction. The motor is running properly on low speed. Or on low enough speed. My problem is with the acceleration. Or I think with the values for jerk and acc, may be. The motor just changes its speed from low value to high. It jumps. I need to do this transition slowly. So my friquency inverter to acc slowly the load. I am not sure how to calculate the values for jerk and refspeed_krpm so for example the motor to acc from 0.1 krpm to 0.2 kprm for 1s. not jumping immediately to 0.2..

    Thanks!

    PP: I think in the lab06b there is offset and Rs recalibration on. So I will try to change the program. I will first do this recalibrations and then I will start the vel plan, because using the var window in the ccs I can`t do this immediately after the stack is online and the motor starts spinning at 0.0 krpm and I think this somehow disturbs the velocity plan. I will ensure that the motor is not running and the beginning. And see what is going to hapen.

  • 0 in reply to Pavlin Stoyanoff
    Expert 1655 points

    OK! I am doing it wrong! When I perform lab06b without velocity plan the motor spins correctly. Only on low speeds it experience disturbences for about 0.5-1s I think because of the internal break and the conical structure. On high speeds there is no problem. Do I have to decrease/increase  the jerk or the USER_SYSTEM_BANDWIDTH  which is 20 in order to remove these disturbances? 

    Second: If I use velocity plan the motor starts spinning before I have an opertunity to turn on the plan. I should wait for systemator to go online and than to activate the plan. But as I said the motor starts spinning even when 0.0 is set. And this somehow breaks the estimater and it need a few seconds to adjust. 

    I can monitor the same problem if I separate the main program on 2 -> first I activate the system just to do the offset and Rs recalibration as your manual suggest to be done periodicaly(to simulate a real inverter work) and when I reach the point where the estimator is online I turn on the system and wait for new sygnal. So after another activation of the system offset and rs recalibration is offline, but the motor doesn`t start spinning correctly and it takes 3-4-5 seconds to adjust. Like the estimator is not properly set.

    What am I doing wrong?

    Do I have to reset the estimator somehow?

    Thanks!

  • 0 in reply to Pavlin Stoyanoff
    TI__Guru** 114200 points

    No. You don't need to reset the estimator.

    Please take a look at the lab guide at the folder of the motorWare and the InstaSPIN User's Guide at link below, follow the guide to tune the identification parameters. Both guides include all of the supporting information we can provide for InstaSPIN-motion.

    \ti\motorware\motorware_1_01_00_18\docs\labs

    InstaSPIN-FOC and InstaSPIN-MOTION User's Guide f (https://www.ti.com/lit/spruhj1)