Issue with BLDC motor control

Hello,

I am in big trouble with sensorless BLDC motor project. I am trying to achieve the control of sensorless BLDC motor using microcontroller.

I am using renesas microcontroller RL78-G14. I am able to run the motor but not getting first start.

I am trying by sequence changing with particular delay but its not working.

Once I rotate motor with hand, the motor is starting and then control is through back EMF.

At back EMF stages the motor is working properly. I am worried about my project just because of start up issue.

Please help me with the code to start the initial rotations.

Seriously I am worried about my project.

Requesting you all to reply me.

  • Pica,

    Sounds to me like you just need to send a short signal to your motor to rotate then start your feedback loop.

    Let us know how it works out.

    Mike Clements
    RenesasRulz Moderator
  • In reply to Mike Clements:

    Mike,

    First of all thanks for your reply.

    Thank god you understood my issue.

    What I am doing is, I am trying with delay to tilt motor slightly. But the thing is that it does not works.

    Let us consider two commutation -

    1) manual commutation- using delay
    2) motor commutation- using motors back emf

    At start we need manual commutation. If motor has some load, then it is not starting. Also the current at start even with load or without load is higher.

    Please suggest your views.

    Awaiting for your valuable reply.
  • In reply to Pica:

    Can Anyone please help me?
  • In reply to Pica:

    No response since long time. Please update me.
  • In reply to Pica:

    Pica,

    Have you gotten your motor working?

    Mike Clements
    RenesasRulz Moderator
  • In reply to Mike Clements:

    No, I am still struggling to start the Motor .
  • In reply to Pica:

    What type/model of brushless DC motor are you using?
    Do you have a part number or data sheet for it?

    Mike Clements
    RenesasRulz Moderator

  • In reply to Mike Clements:

    Hello Mike,

    We are our own motor Manufactures.

    Please find the following motor specifications,

    Voltage- 18-30V
    Current- 30A Max
    Number of turns -15
    number of poles- 18
    number of slots-16
  • In reply to Pica:

    Hi Pica,

    I am very sorry with the very late response. Can you tell us what RL78/G14 specific board did you used? Also, please tell us what motor driver did you used to drive the motor. It could be possible that problem has something to with the driver.

    JB
    RenesasRulz Forum Moderator

  • In reply to JB:

    AP3.pdfHello JB,

    Thanks for your reply. I am always waiting for your reply as you are always helping me in late responses.

    Thanks.

    I am using RL78/G14 micro controller. The controller part number is R5F104BA. The driver is generalized driver. I am attaching schematic diagram for your reference.

  • In reply to Pica:

    Are you just using the chip alone? or did you used something like this secure-resource.renesas.com/.../yrmckitrl78g14_photo.jpg ?
  • In reply to JB:

    I am using chip alone.
  • In reply to Pica:

    As I can see with the schematic diagram, you really did made your own hardware design for the driver and the sensors. Honestly, it would be really difficult for us to debug your issue since we don't have the same driver that you are using right now. But if the issue is with the program, you can try to look at this board www.renesas.com/.../YRMCKITRL78G14.html or this link www.renesas.com/.../rl78.html if it has some examples for driving the BLDC motor. Also, it would help the forum if you will attached the code that you are uploading to the microcontroller. There's also a code generator for RL78/G14 devices which you can find here www.renesas.com/.../rl78g14.html Hope you understand the situation.

    JB
    RenesasRulz Forum Moderator
  • In reply to JB:

    Hello JB,

    I have found the exact issue previously. The issue is in software part as the same hardware I am using for sensored motor driver. Hardware is not a problem. May be software I have written has little bit different or any other issue in software. How to resolve this?

    Please suggest your views.
  • In reply to Pica:

    Oh I see. If that's the case, I would suggest that you post your code here with the IDE that you are using so that the forum can analyze it. And if you are using the same hardware for the motor control, maybe you can get idea from this page www.renesas.com/.../rl78.html supporting files.

    JB
    RenesasRulz Forum Moderator