Learning Forum

[JUNAED HOSSAIN]

I am trying to design a BLDC motor (Fig1) where the three phase windings are being excited by external circuit (fig 2). I am considering six step commutation process where I am specifying the commutation points based on back emf curve like that of fig 3. However I am getting a slight distorted current shape for stack length 52.85 mm (fig4) wherease I am getting a good current shape for stack length 51.5 mm (fig 5). I updated the phase resistance values for each case pror simulation. What can I do to get a good current shape like fig 5 for the case of stack length 52.85 mm (fig 4) ? If anyone has faced such issues please share your insight and solution if possible.

   

fig 1 : BLDC 2D FE model

fig 2 : External Circuit

fig 3: Back Emf Curve

FFig 4: Distorted Current Shape and Fig 5 : Desired Current shape

[Navya Chode]

Hi junaed,

Your question is being answered in the below post.

Distorted Current shape in BLDC Motor excited by external circuit (ansys.com)

Regards,

Navya