Timeline for Correct understanding of torque constant for BLDC using FOC
Current License: CC BY-SA 4.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Dec 3, 2023 at 11:17 | answer | added | Leon LeGa | timeline score: 1 | |
| Aug 22, 2023 at 16:50 | comment | added | John D | You can let the Id current go to zero in a permanent magnet machine because the d-axis flux is supplied by the magnets. In that case the specified torque constant is likely accurate. However you don't HAVE to let the d-axis current go to zero. You can fight the magnet flux to get higher speed (lower BEMF) but lower torque for example. In that case the torque constant will be different from the nominal. I don't have a reference handy, but if I can find one I'll link it here. | |
| Aug 22, 2023 at 7:11 | comment | added | Victo Rien | Thanks for your answer. In typical FOC, the Id current is controlled to reach 0 Amp. I don't get why we can't let the d-axis flux go to zero. Do you have a hint or documentation link to help me understand ? And so you confirm that torque constant equation is actually true only in specific condition ? | |
| Aug 18, 2023 at 15:44 | comment | added | John D | If you're using FOC you can independently control the d-axis and q-axis flux. Even with a permanent magnet machine you can do flux weakening by "fighting" the magnet's flux. However, you need both in order to produce torque, you can't let the d-axis flux go to zero. The torque constant will vary based on how you choose to control the d-axis flux. The stated torque constant probably assumes that the d-axis flux is the nominal permanent magnet flux. | |
| S Aug 18, 2023 at 8:08 | review | First questions | |||
| Aug 18, 2023 at 9:26 | |||||
| S Aug 18, 2023 at 8:08 | history | asked | Victo Rien | CC BY-SA 4.0 |