• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 82 subscribers
  • Views 674 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BLDC BACK EMF AND CURRENT SHAPE

vijay kumar konenki
Prodigy 10 points

I am using a 72v,5kw bldc motor, for this motor i need to know the amount of back emf and current we get when the motor supply is removed suddenly.................

  • 0
    Genius 5170 points

    May be I am not undestanding your question but if you disconnect your motor from supply then there shouldn't be any current ...and the back EMF will depend on the speed of the rotation ...your BLDC motor specification may provide the information on the relationship between back EMF and RPM.

  • 0
    Intellectual 995 points

    Yes, there will be huge voltage originated from inductivity of the motor coils at the very moment supply is detached - GVolts and even more - dI/dt tends to infinity due to the fact that the circuit is broken

    vijay kumar konenki said:
    suddenly
    . This voltage' destructive effect can be compensated with the protective diod's capacity and somewhat with the transistor's one.

    The current's shape then will be determined by the L-C contour of the Diod-Coil circuit - classic L-C energy transition process.

    That is theory.

     

    vijay kumar konenki said:
    when the motor supply is removed suddenly.................

    As far as practice is concerned, use the current transformer in the very point of interest and You'll see current shape with any data acquisition device.

    Regards.