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MCF8316AEVM: Motor efficiency

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Prodigy 60 points
Part Number: MCF8316AEVM
Other Parts Discussed in Thread: MCF8316A

Tool/software:

Hello,

The results of our efficiency measurements are shown in the graph above. I have a question that has been puzzling me, I want to test the efficiency of the motor, according to the theory should be the output power divided by the input power, but when the power supply is 18.6V, the motor is subjected to a voltage of 13V at 3600 rpm, our power tester is the DC regulator source is connected to the power supply of the MCF8316A EVM, so the input voltage and current recorded is also the power supply this The input voltage and current recorded is also the voltage and current of the power supply. Based on the above description, I have the following questions.
1. I would like to know if the efficiency measured this way is accurate?
2. I would like to know the internal structure of the MCF8316A chip.
3. can I know the real time current of the motor? If so, please tell me how to do it.
I would appreciate if you could reply as soon as possible.

  • 0
    TI__Mastermind 23682 points

    Hi,

     To measure efficiency with EVM you can follow the steps 

    1) Measure the base current without running the motor at given voltage.

    2) Run the motor at good speed and ensure phase current is sinusoidal so that Phase current is well aligned with BEMF which is the best efficiency point, I hope motor is well tuned- Motor parameter R, L should be proper 

    3) If you use the power analyzer to measure the phase voltage on the UVW nearest to the pin so that PCB resistor loss can be reduced.

    Can you share your JSON file along with motor parameters?

    Answer to your questions

    1. I would like to know if the efficiency measured this way is accurate.  It is correct on the broader level, better to measure each section modular way and eliminate non motor related losses.
    2. I would like to know the internal structure of the MCF8316A chip. What is the power mode , is it Buck or AVDD mode? You can see internal block diagram of the MCF8316 in the data sheet.
    3. can I know the real time current of the motor? If so, please tell me how to do it. Using current probe with oscilloscope is correct way to measure the winding current of motor.

    Thanks and Best Regards

    Venkatadri S

  • 0 in reply to Venkatadri Shantaram84961
    TI__Mastermind 23682 points

    Hi,

    Do you have any update on this? If resolved, can you please close this and start new thread?

    Thanks and Best Regards

    Venkatadri S