changing resistance of BLDC motor

i m making a 3d printed wind turbine n as a generator i m using bldc motor. what i want is to give a signal from my phone so that resistance of motor increases n turbine stops moving even if there is wind. i searched the net n found about ESC but i dont know if it will work on motor which is giving output. thank u in advance.

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I'm pretty sure you need a physical brake for this. I don't think any electronic means of slowing down the turbine will be very effective.

I could be wrong though.

but the one i have is a very small 3d printed model.

I don't know the details of the bldc nor the torque to stop the turbine. I tend to agree with Jiggy-Ninja that the bldc may not be sufficient.

That being said:

  1. Shorting the bldc outputs will add torque but only if the motor rotor is moving. Would slow it down but not keep it stopped.

  2. Applying a DC current to the windings will hold the rotor in one position. Usually on a 3 wire bldc you just apply current to 2 leads.
    How much current you need will have to be determined by your testing. Also keep in mind there is no air over the bldc so you have to worry about overheating the windings.

Good Luck

John

i m using this motor. if it helps. just so u know i dont a lot of details in this area so if possible would appreciate if got a detailed solution if there is any.

sumitb:
i m making a 3d printed wind turbine n as a generator i m using bldc motor. what i want is to give a signal from my phone so that resistance of motor increases n turbine stops moving even if there is wind. i searched the net n found about ESC but i dont know if it will work on motor which is giving output. thank u in advance.

You need to decrease the resistance to brake a motor (ie increase the current) since torque
is proportional to current.

You need to treat the turbine as a motor-generator and need at east 2 and possibly 4 quadrant control
to do this. To stop the rotor you'll need some means of sensing its position to drive the feedback
control loop. It will consume power rather than generating when doing this, note.

i know i need to change resistance but how to do it

Any reasonable solution would include a brake and a lock. After action, it is simply locked and doesn't consume energy to keep it locked. Then a new action would release the lock and it would start spinning again. But are you looking for a solution where a current is driven through the motor to prevent it from rotating?

sumitb:
i know i need to change resistance but how to do it

2 or 4 quadrant control. The resistance of the copper doesn't change, note, the effective resistance
is dominated by the back EMF, and can be negative if the current reverses. 4-quadrant control
allows the current to flow in reverse and for the applied EMF to be reversed, giving the most general
control. Read up on DC motor control.