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TIDA-010265: Issue during closed-loop transition in TIDA-010265 (F2800137, ESMO)

M Ranjith Rai
Prodigy 65 points
Part Number: TIDA-010265


Dear TI team,

I am currently working on a PMSM motor control setup using the TIDA-010265 reference design with the F2800137 MCU and the “tida_010265_gminv_280013x” code base. I am using ESMO for estimation (not using FAST for now).

Below are my motor parameters and configuration details:

  • Motor type: PMSM

  • Pole pairs: 5

  • Phase-to-center resistance: 46.5 ohm (measured phase-to-phase at 100 Hz using LCR meter, divided by 2)

  • Phase-to-center inductance: 136 mH (measured phase-to-phase at 1 kHz using LCR meter, divided by 2)

  • Issue Description:
    The motor runs as expected up to DMC_LEVEL_3 at the commanded speed. In DMC_LEVEL_4, the motor ramps up properly in open-loop mode (forced up to 70 Hz). However, the moment it transitions to Closed loop(commanded 75 Hz), the motor starts vibrating severely instead of maintaining stable rotation.

    I have attached the Phase current waveform captured at the instant of transition from open-loop to closed-loop for your reference.

    Additionally, I have included the “user_mtr1.h” file containing all modified motor parameters. Except for that file, in the esmo.c, the value of obj->pll_Ki is kept at 0.001f(changed from the default value 0.0f because speed feedback was nit changing and was varying near zero even in lower DMC levels).

    Additional Observation:
    While debugging, I noticed that sometimes the speed feedback updates correctly, but other times it remains constant and does not reflect the actual motor speed (observed in the debug window).

    Could you please help identify the possible causes of this unstable closed-loop behavior and suggest which parameters or tuning aspects I should verify?

    Attachments:

    1. Phase current waveform during closed-loop transition

    2. user_mtr1.h (with all modified parameters) user_mtr1.h b5915a57-122f-49c2-9334-8646de808766.jpg

    Best regards,
    Ranjith Rai

  • 0
    Prodigy 65 points

    Dear TI Team,

    I’m using the TIDA-010265 reference design with the F2800137 controller and the ESMO estimator for sensorless control. The motor runs smoothly in alignment and open-loop modes, but when it transitions to closed-loop (around 40 Hz), I consistently observe a sudden drop in speed, as shown in the attached plot. The commanded run speed is 70 Hz. After the transition, the motor speed dips sharply and then tries to recover. I have tuned the PLL proportional and integral gains to improve recovery, but the results are inconsistent — even a small change in PLL gain can cause the motor to vibrate, fail to recover, or sometimes rotate in the reverse direction.

    In some cases, I also notice that the variable “speedPLL_Hz” suddenly jumps to the maximum limit I have set (110 Hz) and remains there, regardless of the commanded speed. The motor does not recover from this condition until it is stopped and restarted.

    The same code and motor parameters work perfectly when the FAST estimator is enabled, or when both FAST and ESMO are enabled. This issue occurs only when ESMO alone is used. The motor parameters shown in the image are auto-identified values. Could you please help me understand the reason behind this sudden speed drop during closed-loop transition when using ESMO, and suggest how I can resolve or minimize it?