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Visitor
August 27, 2026
Question

How to solve the problem that the HSO is sensitive to the motor phase resistance

  • August 27, 2026
  • 3 replies
  • 63 views

I have a motor whose phase resistance is 40 mΩ at 20 °C and 45 mΩ at 70 °C. When I set the phase‑resistance parameter to 40 mΩ, the motor operates normally at around 20 °C. However, when the motor temperature rises to approximately 50 °C, frequent start‑up failures occur. How can this problem be resolved?

3 replies

GMA
ST Technical Moderator
August 27, 2026

Hello ​@XGL,

Did you try selecting Start Up RsDC Estimation feature?

If you agree with the answer, please accept it by clicking on 'Best answer'.Best regards.GMA
XGLAuthor
Visitor
August 27, 2026

Thanks for your reply. I hadn’t enabled this feature. But if I turn it on, won’t errors in resistance identification impact the start‑up function?

XGLAuthor
Visitor
August 27, 2026

Under the condition of the conventional STO observer, the influence of phase resistance appears to be minimal. From this perspective, the HSO seems less stable than the STO.