MCF8316AEVM: Motor not drie

Hi Kenji,

What does the algorithm status show? Is it stuck at "MPET Ke measurement"? Can you try decreasing the MPET open loop current reference? If this doesn't work then can you increase the MPET Open loop speed reference?

Regards,

Vishnu

Hi Vishnu Balaraj - san

I follow the GUI guide steps.

In MPET step (#2 of photo), I increase the speed with a resistor, it will rotate until the current reaches 0.25A, and then it will stop without error.

About this, is it okay to think that the measurement is over correctly?

After that, even if the resistance is returned to 0Ω and changed the speed again, the motor will not rotate.

Hi Kenji-san,

Since you have not enabled "Auto read fault status" and "Auto read motor status", I'm sure at what state the algorithm is and what fault is getting triggered. Can you repeat the experiment by enabling both statuses? As mentioned in my previous post, if the fault is "MPET Ke measurement", can you try decreasing the MPET open loop current reference? If this doesn't work then can you increase the MPET Open loop speed reference?

Regards,

Vishnu

Hi, Vishnu Balaraj - san

Enabling Auto Read Motor Status and Auto Read Fault Status does not change the situation, no error.

Hi Vishnu Balaraj

This problem is not solved yet. After MPET, motor not run.

And I decrease the MPET open loop current  and increase the MPET speed but, Moto not work.
It failed in MPET Ke measurement.

Do you see the motor spin during Ke measurement? If the BEMF constant of this motor is less than 1 mV/Hz then it is  not possible for MPET to measure the Ke. Do you have the motor datasheet? 

Hi Vishnu Balaraj -san

Motor spin during Ke measurement.
After end measurement, even if command via I2C or analog, PWM duty, motor not spin.

My motor flux is 1.241mV/Hz.

Also I tested with another one motor.

BR2804-1700KV, 14poles, max18krpm, Rs=0.11ohm, flux=0.4Vrms/Krpm

This moter also not end Ke measurement.

Question:

1. Is it possible to spin the motor by omitting Ke measurement and setting the parameters directly?
   
2. After failed, Ka measurement, EVM board still communication from 0xE0 to 0xE8 commands. Auto read fault and motor status is disable, but still asking status.
   It seems that not accept another command like I2S speed. Is this the cause of motor not spin?
   

Kenji,

Kenji said:

Is it possible to spin the motor by omitting Ke measurement and setting the parameters directly?

Yes, it is possible. You can go to the "Control configurations - Motor parameters" section in the "All tunings" page in the GUI and program Ke. 

Kenji said:

After failed, Ka measurement, EVM board still communication from 0xE0 to 0xE8 commands. Auto read fault and motor status is disable, but still asking status.
It seems that not accept another command like I2S speed. Is this the cause of motor not spin?

 I didn't quite understand your comment/question. Here are the steps to follow to resolve this issue.

1. Power cycle the device.

2. Follow the steps in Essential controls section in the Guided tuning.

3. Before you issue the I2C command, Program Ke as explained in the previous comment.

4. Go to "Control configuration - Closed loop" and program the Speed loop Kp and Ki to 0.1 and 0.01. These are just random values to get the motor spinning. If these are programmed to 0, device will run MPET Ke and you will never be able to come out of this loop. 

5. Issue the I2C speed command. 

You should now see the device spin the motor. If there are any faults, check the fault register and let us know what fault is getting triggered.

Regards,

Vishnu