BLDC sensorless motor control using sample code(S12ZVML-MINIBRD)

whaleshark — Mon, 25 Nov 2024 04:59:46 GMT

Hello all.

I want to know how to calculate the parameter for proper paramter to normal working.

I am testing with an MTRCKTSPNZVM128 EV board.
In the S12zvml mini-brd sample code, bldc is referenced.

S12ZVML 3-phase BLDC/PMSM Evaluation Kit | NXP Semiconductors

I checked that the motor on the ev board is running, but it's not working on the target motor.
It flinches slightly with a whine, then stops when one of the 'Idcb HI', 'GDU', and 'Stall' errors occurs.
I suspect that it is because the parameter value in the sample code is different.

The target motor has 14 poles. And it is being developed at 500-25000 rpm.
So I'm going to test it while modifying the value, but I don't know how to calculate it. I'm asking if there's a calculation formula.

Below is the parameter in the sample code.

/***** High speed scaling *********************

* For 4 pole-pairs motors

* Boundary values for 1.28 us timer period:

* - Minimal speed: 60 rpm

* - Minimal speed scaled: 86

* - Maximal speed: 22887 rpm

* - Maximal speed scaled: 32767

*********************************************/

#define SPEED_CALC_NUMERATOR 16777216

#define STALLCHECK_MIN_CMT_PERIOD 97 // 97 = 125 us (20 krpm on 4 pole-pairs motor), min value = 85 (22.89 krpm)

#define REQUIRED_RUN_SPEED (1432*2) // 2000 rpm

// 1431.655765 = 1000 rpm

#define MIN_SPEED (1432/2) // 500 rpm minimal speed for Down button control (should be min 10% of nominal motor speed)

#define MAX_SPEED (1432*5) // 5 krpm maximum speed for Up button control

#define SPEED_STEP FRAC16(100.0/22887.0) // 100 rpm, Up/Down step for button controls

#define BTN_PERIOD_DIVIDER 100 // scan buttons every 0.1 s only

//*****

Re: BLDC sensorless motor control using sample code(S12ZVML-MINIBRD)

RadekS — Thu, 28 Nov 2024 17:19:18 GMT

Dear whaleshark,

Please look at detailed answer here: https://community.nxp.com/t5/S12-MagniV-Microcontrollers/BLDC-Motors-param/m-p/700945#M14540

I hope it helps you.

Best regards

RadekS

topic Re: BLDC sensorless motor control using sample code(S12ZVML-MINIBRD) in S12 / MagniV Microcontrollers

BLDC sensorless motor control using sample code(S12ZVML-MINIBRD)

Re: BLDC sensorless motor control using sample code(S12ZVML-MINIBRD)