dforesi
10 mW
- Joined
- Mar 3, 2021
- Messages
- 31
Hello everyone,
While I have a background in mechanical engineering, I am not motor specialist, and I know several of you are. I was reading an article (credibility TBD) recently and two items stuck out at me that I thought were incorrect.
The paper is discussing the efficiency differences between standard AC induction motors and Permanent Magnet Motors. Keep in mind, the application here is steady state operation. The following claims were made:
(when discussing the switch from AC induction to PMM) - Efficiencies are gained by the magnets working to spin the rotor, as opposed to a standard induction motor that requires additional electricity to induce the magnetic field into the rotor.
- Is this even remotely correct? I thought the advantage of PMM was better starting torque with the draw back of poor high speed efficiency due to back EMF
Additionally:
PMM motor design is much more energy efficient when compared to the standard induction motor, achieving efficiency ratings of 90% while the average AC Induction motor will have efficiency ratings between 30% and 70%. - This seems completely incorrect based on my understanding. We are talking about 2000-3500rpm operation so I assume back EMF on PMM wont be a huge difference, but I thought AC induction and PMM efficiency at steady state was roughly similar.
I am confident that these claims are at best mis-leading, but I am still learning and would like to hear from you before I make any final judgement.
Thank you!
While I have a background in mechanical engineering, I am not motor specialist, and I know several of you are. I was reading an article (credibility TBD) recently and two items stuck out at me that I thought were incorrect.
The paper is discussing the efficiency differences between standard AC induction motors and Permanent Magnet Motors. Keep in mind, the application here is steady state operation. The following claims were made:
(when discussing the switch from AC induction to PMM) - Efficiencies are gained by the magnets working to spin the rotor, as opposed to a standard induction motor that requires additional electricity to induce the magnetic field into the rotor.
- Is this even remotely correct? I thought the advantage of PMM was better starting torque with the draw back of poor high speed efficiency due to back EMF
Additionally:
PMM motor design is much more energy efficient when compared to the standard induction motor, achieving efficiency ratings of 90% while the average AC Induction motor will have efficiency ratings between 30% and 70%. - This seems completely incorrect based on my understanding. We are talking about 2000-3500rpm operation so I assume back EMF on PMM wont be a huge difference, but I thought AC induction and PMM efficiency at steady state was roughly similar.
I am confident that these claims are at best mis-leading, but I am still learning and would like to hear from you before I make any final judgement.
Thank you!