TMS320F280025: Inductance Estimation ACIM

Part Number: TMS320F280025
Other Parts Discussed in Thread: MOTORWARE

Tool/software:

Hi,

It seems, that the inductance estimation frequency for my ACIM motor is extremly slow and I don't know how to change that. I'm using the MotorControl SDK V5.0.2 with custom hardware.

The hardware works fine for PMSM motors so far (identification like in the datasheet on several motors), but for ACIM there seems to be a problem.

The overall estimation seems like in the spruhj1i, except the inductance and Rr estimation is extremly slow in my example.

From Docu:

Measured (Note that there is some noise on the current probe, the actual signal looks pretty good):

IdMag:

After IdMag found:

So the motor works fine after identification, but I'm not sure if the measured inductance is good or not (probably not).

The parameters I'm using are:

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#define USER_MOTOR1_TYPE MOTOR_TYPE_INDUCTION
#define USER_MOTOR1_NUM_POLE_PAIRS (1) //Only 1 pole pair
#define USER_MOTOR1_Rr_Ohm (NULL)
#define USER_MOTOR1_Rs_Ohm (NULL)
#define USER_MOTOR1_Ls_d_H (NULL)
#define USER_MOTOR1_Ls_q_H (NULL)
#define USER_MOTOR1_MAGNETIZING_CURRENT_A (NULL)
#define USER_MOTOR1_RATED_FLUX_VpHz (0.8165f*230.0f/50.0f)//(0.8165f*400.0f/50.0f) //STAR: 230VAC, DELTA: 400VAC
#define USER_MOTOR1_RES_EST_CURRENT_A (0.5f)
#define USER_MOTOR1_IND_EST_CURRENT_A (NULL)
#define USER_MOTOR1_MAX_CURRENT_A (2.0f)
#define USER_MOTOR1_FLUX_EXC_FREQ_Hz (5.0f)
#define USER_MOTOR1_NUM_ENC_SLOTS (NULL)
#define USER_MOTOR1_INERTIA_Kgm2 (7.06154e-05f)
#define USER_MOTOR1_FREQ_NEARZEROLIMIT_Hz (1.0f) // Hz
#define USER_MOTOR1_RATED_VOLTAGE_V (400.0)
#define USER_MOTOR1_FREQ_MIN_Hz (1.0) // Hz
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

So the flux excitation frequency is 5Hz and according to the manual, that should also be used for the inductance estimation, but it seems only to start with that. Any idea, what is going wrong here?

Edit: Are there somehow more information, why the motor does not keep the flux exitation frequency? only get EST_STATE_LS from the estimator, but not why it is not keeping up the field frequency?

  • Hi,

    Sorry for the delay. You are evaluating the Universal Motor Control Lab, correct? There are some specific considerations for ACIM vs PMSM motor ID.

    I will see if someone with more expertise on our motor ID routine can offer some suggestions. I will provide some thoughts below for the time being.

    • Suggest reviewing appendix section of https://www.ti.com/lit/spruj26 as well. It is specific for the UMCL
    • You should need to define 'USER_MOTOR1_MAGNETIZING_CURRENT_A' parameter for ACIM as well. There are some examples of what we used for other motors in 'user_mtr1.h' file

    Best,

    Kevin

  • The lab and FAST algorithm are not validated for ACIM, and it's not recommended for ACIM as well. If  you want  to use the InstaSPIN-FOC for ACIM, please try to use the lab and the supporting devices in motorWare.

  • Hi,

    Ok, so you only support ACIM on the old microcontrollers (picolo) that are compatible with motorWare? Will there be support for the new C2000 in near future? 

  • You can design your own algorithm for ACIM with any C2000 devices. We have plan to design and update the algorithm for ACIM as well, but it's not available in a short time.