motor control blockset estimate pmsm parameter failed

HI everyone,

I have set a motor control environment to learning motor control

• LAUNCHXL-F28379D
• BOOSTXL-DRV8305EVM
• 36V pmsm with hall sensor and quadrature encoder senser(only A and B phase) feedback

and I ran "mcb_param_est_f28379D_DRV8305.slx".

when I choose "HALL" in sensor selection, the result is correct. below are host gui and theta measured

when I choose "QEP" in sensor selection, rotor doesn't rotates well so bemf, inertia and theta are wrong

can you help to solve this problem?

notes:

• I have calibrate encoder offset use "mcb_pmsm_qep_offset_f28379d.xls" and it works well

• control parameter used in "mcb_param_est_host_read.xls" are showd below

[Nivedita]

Hi 静静,

Can you try the other example 'mcb_pmsm_param_est_f28379d.slx' provided in the documentation and check if the problem still exists?

The example can be found in the documentation here: Estimate PMSM Parameters Using Parameter Estimation Blocks - MATLAB & Simulink Example (mathworks.com)

Answer 1

[Shivaprasad Narayan]

The Back EMF estimation technique in motor control blockset needs the motor to be run in closed loop Field Oriented Control beyond 80% of the motor rated speed.

If the rotor does not spin smoothly using QEP but works well with Hall sensor inputs, the issue is with the quadrature enocder.

Make sure the encoder slits and number of pole pairs are correctly configured in the offset calibration model before the calibration process.

Update the calibrated encoder offset value as well as the encoder slits value on the parameter estimation host model. This is expected to spin the rotor well and estimate the Back EMF.