XMC4500 FOC execution time and CPU load

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Hello team,

I am working wtih XMC4400 and XMC 4500 controllers for one of requirement of motor control.
PWM frequency: 90KHz
Motor speed : 60KRPM
Sensorless FOC control
Please help me by providing FOC execution time and CPU load in percentage when PWM frequency is 90KHz and let me know what FOC frequency you have considered while execution.

Regards,
Pranoti
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6 Replies
Travis
Employee
Employee
First solution authored Welcome! 500 replies posted
pranotis wrote:
Hello team,

I am working wtih XMC4400 and XMC 4500 controllers for one of requirement of motor control.
PWM frequency: 90KHz
Motor speed : 60KRPM
Sensorless FOC control
Please help me by providing FOC execution time and CPU load in percentage when PWM frequency is 90KHz and let me know what FOC frequency you have considered while execution.

Regards,
Pranoti



Test Setup:
HW: XMC4000 Application Kit: XMC4500 CPU Board (CPU_45A-V2) + Motor Drive Card (MOT_GPDLV_V2) + Motor (24V, Nanotec P/N: DB42S03-KINF).
SW: Infineon sensorless FOC with single-shunt current sensing (without using any DAVE Apps).
IDE: DAVE 3.1.10
Compiler: ARM-GCC C Compiler, Optimization level: O3.
Inverter PWM for test: 20kHz, so PWM period: 50us.

Test Results:
XMC4500 execution time for sensorless FOC function:
6.8us, with SW CORIDC iterations = 8. So CPU load = 6.8us/50us = 13.6%.
8.0us, with SW CORIDC iterations = 12. So CPU load = 8.0us/50us = 16.0%.
9.0us, with SW CORIDC iterations = 16. So CPU load = 9.0us/50us = 18.0%.

For Customer’s Application:
If customer uses 90kHz PWM (PWM period = 11.1us) and selects above SW CORIDC iterations = 8, the XMC4500 CPU load is estimated as: 6.8us/11.1us = 61.2%.

Further Improvements:
If necessary, customer can do 1) further code optimization, 2) use more effective C compilers, and/or 3). use Look-Up Table (LUT) for Park/Inverse Park Transform, etc. to decrease the CPU load.
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Dear Travis,
Thank you so much for this fruitful information, it will be gonna help me alot.
Can you please explain what is SW CORIDC iteration? or suggest me any document/URL to understand this concept.

Regards,
Pranoti
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Travis
Employee
Employee
First solution authored Welcome! 500 replies posted
pranotis wrote:
Dear Travis,
Thank you so much for this fruitful information, it will be gonna help me alot.
Can you please explain what is SW CORIDC iteration? or suggest me any document/URL to understand this concept.

Regards,
Pranoti


There you go...

http://en.wikipedia.org/wiki/CORDIC
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Not applicable
Dear Travis,

Thank you so much.
We need to suggest XMC4500 controller to our customer for which we need confirmation of above FOC execution results from Infineon.
Can you please share any document regarding this which will confirm that above results are authenticated by infineon..

Regards,
Pranoti
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Travis
Employee
Employee
First solution authored Welcome! 500 replies posted
pranotis wrote:
Dear Travis,

Thank you so much.
We need to suggest XMC4500 controller to our customer for which we need confirmation of above FOC execution results from Infineon.
Can you please share any document regarding this which will confirm that above results are authenticated by infineon..

Regards,
Pranoti


Sorry to say that there is no official document on this topic.
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Charm
Employee
Employee
5 sign-ins First like given 5 replies posted
Hello Pranoti, the above data are measured with due diligence in our lab. You should be able to take this to your customer for their evaluation. Cheers.
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