Hi Grahame,

Can you share the SmartTune log screen capture to debug this issue? After a SmartTune failure, could you please check whether the motor resistance, inductance, and BEMF parameters have been updated? If you see that these variable values have been updated, then you can run the motor in current loop mode by setting the control mode parameter (PERI_CONFIG1->CTRL_MODE = Current Control).

Regarding the LVBLDCMTR, we can spin the motor using the MCF8329A EVM.

Thanks,

Dhinesh

Hi Dhinesh
Thanks for confirming that the LVBLDCMTR will work with my evaluation module.

I have tried to run SmartTune again to day. I have never been able to get it to update the Resistance, Inductance or BEMF parameters.

I have set the Basic information to the following;

No Load
Rated Voltage 24 volts
Rated Current 1 Amp
Rated Speed 1800 Hz
Shunt Resistance 1 mohm

I have never received a fault monitor log until today. I am currently getting CONTROLLER_FAULT and HW_LOCK_LIMIT flashing on and off. The board seems to be in some kind of loop state where the faults are reset and then reoccur. Please see the attached screen shot for more details.

SmartTune does appear to run after a power up. The motor starts but then trips out with the following faults.
CONTROLLER_FAULT
ABN_BEMF
MTR_LCK

I am having trouble uploading the screen shot.
I will send another message once I have worked it out.

Thanks

Grahame

Hi Dhinesh
This is the manufacturer's data sheet for my motor. It contains all the data that the manufacturer is able to share with me.
I asked them some more specific question about the phase inductance but they where unable to provide a figure.

Thanks

Grahame

Hi Dhinesh

I have been reviewing the Tuning Guide document whose version information is shown below.
MCF8329A Tuning Guide SLLU374 – NOVEMBER 2024

Is this the latest document? It doesn't seem to match the version of Motor Studio that I am using.

This is the version information for the version of Motor Studio that I am using.

Thanks

Grahame

Hi Grahame,

1mohms is too low for the 1A motor current, could you please replace the shunt resister with 10mohms and try the SmartTune once?

you can also try using the default tuning files provided here. Please look into this file - BLDC_fan_40A_1p8KHz_MCF8329A.json

Yes, Tuning need to be updated with the latest version of MotorStudio GUI. we have a plan to update the tuning guide.

Thanks,

Dhinesh

Thanks, Dhinesh
Do you think I might be able to achieve something in the short term by increasing the gain of the CSA to maximum, 40v/v I believe?

Hi Grahame,

Yes, we can try testing it using 40V/V but it would be better if you replace the shunt resister to 10mohms.

Thanks,

Dhinesh

Thanks, Dhinesh

Hi Dhinesh
Does the LVBLDCMTR motor work with a CSR of 1mΩ? on the MCF8329EMV?
Does the CSR need to be increased if I use the LVBLDCMTR?

Thanks

Grahame

HI Grahame,

No, LVBLDCMTR motor rated current is very low (0.5A) for the EVM shunt resister 1mohms.

Please replace the shunt resister with 10mohms.

Thanks,

Dhinesh

Thanks, Dhinesh
I will order a 10 mΩ current sense resistor from Stackpole.

Once I have it installed I will let you know if the problem is solved.

Hi Dhinesh
I recently posted this in the C2000 Micro-controllers forum and have not received a reply.

I recently purchased an LVBLDCMTR Brushless DC Motor that I intended to use to evaluate the MCF8329A with the evaluation module MCF8329AEVM.
Today I have connected the motor for the first time and started to use the SmartTune feature in the TI Motor Studio software.

I am powering the system with a 24v DC supply. The motor was trying to spin and was drawing about 5 amps when I noticed smoke coming from it. I immediately disconnected the power. I have previously confirmed with a TI person through the technical forum that this motor would be suitable for my application.

It now appears that the motor may be damaged. I can get continuity through the red and yellow phases but the black phase appears to be open circuit.
I would like some advice about what may have happened. The motor shaft was not jammed and I believe I was operating the motor within its advertised parameters.

Is it possible to make a warranty claim? As I do not live in the US how would I go about doing this?

I may have posted this in the wrong forum. Since you have recently advised me about the LVBLDCMTR I am wondering if you can help with my question?

Regards

Grahame

Hi Grahame,

I will check internally on this and update you.

Thanks,

Dhinesh

Hi Grahame,

Could you please share the motor settings that you used to run the SmartTune tool?

Thanks,

Dhinesh

Hi Dhinesh
The motor settings where the basic ones required by SmartTune.

Rated Voltage 24v

Rated Current 3 Amps

Ratted Speed 2000 Hz (I am not clear about what this one should be but this seemed reasonable)

Speed Mode

No Load

Shunt Resistance 1 mΩ

These settings are the only required ones. Everything else is optional and I wanted to let the system do the calculations.

I have not changed the CS Resistor yet. I just want to see how things worked in the "out of box" configuration first.

My power supply is current limiting and the current never exceeded 5 Amps. The voltage was constant at 24 volts and the rotor was not locked. The motor could be freely turned by hand.

Regarding the CSR. I ordered some higher values from Stackpole as previously discussed. I used the part number listed in the BOM of the Evaluation Kit which referenced a 4 watt 1mΩ resistor. When my new resistor arrived I realised the one on the board is probably only rated at 2 watts. This is probably reasonable since the maximum current is 30A. However, when I increase the value of the CSR to 10mΩ the power dissipation will increase. I will be using a 4 watt resistor. The problem is that it is physically bigger and may not fit well on the board. Consideration should be given in the board design to allow for these higher wattage resistors.

I will change the resistor in the next couple of days. I think it will fit. If you have any comments or advice about this situation, I would be pleased to hear them

Regards

Grahame

Is the LVBLDCMTR internally Star (Y) or Delta connected?

Hi Grahame,

Thanks for sharing the details.

The motor rated speed that you have used is wrong. In the motor specification, the maximum no-load speed is mentioned as 464 Hz, and the rated speed that you have entered (2000 Hz) is four times higher than the maximum no-load speed. SmartTune would have tried spinning the motor to the 2000 Hz speed, which might have caused the motor failure.

Thanks,

Dhinesh

Thanks, Dhinesh
I see what has happened.

I will order another motor in 10 days when the system allows it.

When I get the replacement motor, I give it another try.

Hi Dhinesh
It's taken a while, but I now have the 0.01Ω resistor to replace the existing CSR with.

This will make me sound like a rank armature, but I am having a lot of difficulty removing the existing resistor. The solder is not melting the way I would expect.

I am using a 70W Weller soldering station and have the temperature set to over 250ºC. I am using a nice chisel tip that is about the same size as the component ends.

Can you provide some advice about how to get this resistor removed? 
Are there layers in the board that are acting as a heat sink? What wattage soldering iron do you recommend?

Cheers

Grahame

Hi Grahame,

Shunt resister solder pads are connected to the bigger ground copper pour, so we need apply higher temperature to melt the solder. please try with >350C temperature. we usually do with two soldering iron on both side of the shunt to remove it from the board.

Thanks,

Dhinesh

Hi Dhinesh
Thanks for the advice. I'll give it a try.
Grahame