Need to change board supply VCC to 24V instead of 19V without over voltage error.

[gazzatav]

My motor is rated at 24V volts but the motor control software gives over voltage errors above 21-22V. There seems to be some logic which scales against the ADC reference voltage and generates over voltage errors at around 22V. I suspect there is distributed logic at play here as setting the motor parameters to 24V makes no difference to the sensing. What do I need to change to allow a board supply of 24V?

According to calculations based on info in the user manual, increasing the supply will not push anything over 3.3V (there is plenty of room for scaling up) and damage the board.

[Peter BENSCH]

You have only described your wish, but you have not mentioned the board it is about. I assume, however, that you mean the STEVAL-ESC001v1?

If so, then you can probably bring it up to 24V by changing:

• TVS D5 from SMBJ26A to SMBJ28A and
• the resistor R62 of the voltage divider from 169k to 184k.

However, you should note that the MOSFETs STL160N4F7 also have less reserve (absolute max drain source voltage: 40V). If one of the MOSFETs is fried by a voltage pulse, this could have severe consequences.

Does it answer your question?

Regards

/Peter

[gazzatav]

Thanks for replying. I did not mention the board because I was looking for a motor control software solution which I believe would be similar (if actually possible) on any inverter board. The board is actually a STM32G431 which is very small and if hardware has to be changed it's going to need someone with younger eyes than mine!

[Peter BENSCH]

Of course, one can completely understand that. However, if you want to work with higher voltages, the hardware must be examined closely and adapted if necessary.

If the problem is solved, please mark this thread as answered by selecting Select as best, as also explained here. This will help other users find that answer faster.

Good luck!

/Peter

[gazzatav]

Yes, someone looked at the hardware with me and determined that increasing the external voltage to 24V should not damage anything. The problem is not solved though as I have heard no statement to the effect that it is not possible in software. We have run the board at the higher voltage without harm but the motor fails to run because of over voltage errors. There is a place in MCSDK where over voltage can be turned off so we believed that it should be possible to track down where the error is generated and modify the trigger so we could keep the over volt protection but at a higher voltage. It seems that the logic for this is somewhat 'distributed' though and I thought someone might know the constants to change to get me on the right track or explain why it's not possible.