Experts needed for field weakening option

Electric Motors and Controllers
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10 W
10 W
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Joined: Mar 13, 2017 7:39 am

Experts needed for field weakening option

Post by Rovii » Oct 30, 2017 1:40 am

Hey guys,
I need your help to understand field weakening option!
The thing is that I have tested now my 144V motor at 175VDC up to 200kph top speed for short with Kelly KLS 14401 8080I controller @ 400A max output current.
But to be honest, I do not really know that this current will come out of the controller because I have not measured it!
So my motor has 12,08 Kv that means at no load speed with 160/60-17" tyre = 241, 9 kph!
With my new Emsiso emDrive controller I can handle up to 800A but only 125VDC, so therefore I will only reach 171,2 kph @ no load.
So what I understand from field weakening is that if it´s activated, at my controller at 90% of max voltage it will be automatically starting to reduce the current for the active phase and will push the difference to the max output current to the "non active phases" that they are able to build up a field around the cores which will reduce the magnetic field of the permanent magnets to increase the top speed
Is my understanding here correct?

Also I got a feedback from Emsiso that they have tested it successfully with Emrax 268 motor but field weakening don’t work the same for all motors and I will lost warranty if I will activate it
So what is the meaning of this sentence?

Is there a difference by using different sensor feedback types (e.g. hall sensor-, resolver-, sin/cos sensor type)?

Thanks for your kind support
- Fastest speed record 200,49 kph on flat after 740m (175V, 400A)
- Fastest 1/4 mile @ 157,12 kph on flat and 14.468 sec (146V, 600A)

14/34kW QS-Motor 273 80H 7T winding (560A and 1740 turns @ 144V) @ 169kg GSXR 1000 K2

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