s12ZVM single resistor

[zhouqicheng]

Hello, the code in the official program of s12ZVM single resistor

#Define I_ PH_ Over FRAC16 (0.933333333333)

#Define TEMP_ Over FRAC16 (0.170489770614)

What does this current and temperature actually represent? How to convert? Do you have any relevant program introduction documents

[tomasfedor]

Hi Zhouqicheng, 

In order to explain it I will use files form S12ZVM PMSM Development Kit sw

https://www.nxp.com/design/development-boards/automotive-motor-control-solutions/magniv-and-s12-solu...

I_PH_OVER and TEMP_OVER are located in PMSM_appconfig.h generated by MCAT tool. 

MTRCKTSPNZVM128\sw\AN5327_SW_CW10\FreeMASTER_control\AN5327_PMSM_FOC_Sensorless_SingleShunt.pmp

Values are scaled in FRAC16 format since fraction arithmetic is used. 

in case of S12ZVM PMSM Development Kit sw:

#define I_PH_OVER FRAC16(0.4650000000)
#define TEMP_OVER FRAC16(0.1704897706)

in order to get physical value we need to apply scales

I_PH_OVER * I max = 0.465 * 20 = 9.3A

TEMP_OVER* Temp max = 0.1704897706 * 645.2 = 110 deg C

for more information I recommend application note AN5327. 

Best regards, 

Tomas Fedor.