Controlling PMSM Hub motor

Thread Starter

smitske96

Joined Oct 4, 2021
2
Hi All,

For a project I am busy with a PMSM hub motor (with three hall sensors, 9 pole pairs) that will be part of a 4 motor vehicle with a max target speed of 30km/h.
For Motor control options I am looking at FOC but have some problems with the found info to implement it.

-For FOC you need to know the rotor position, however, the hall sensors are not precise.
-Sensorless FOC could be possible, but the motors will stand still and start a lot of times (hence giving problems with the BEMF). So this also looks difficult for the application.

Does anyone have tips for a solution (or maybe a good search/direction for information)?
 

LowQCab

Joined Nov 6, 2012
1,286
The Motor manufacturer seems to think the Hall-Sensors will work just fine,
why do You think they won't ?
.
.
.
 

Thread Starter

smitske96

Joined Oct 4, 2021
2
Because the rotor position can't be given precisely, Hall sensors would have a 60 degree window.
When I read/hear 5 degree or less is preferred for good operation.
 

LowQCab

Joined Nov 6, 2012
1,286
That's 60-degrees, plus or minus ~5-degrees.
The Hall-Sensors are very likely to be accurate to within ~1-degree, possibly less.

The only time this might be a problem is if you are trying to create
a specialized, extremely high-performance Motor where You are
trying to "eek-out" every drop of Power or RPM that's possible.
Then the exact positioning of the Hall-Sensors may need to be slightly changed
to allow Software to tweak the timing under certain operating conditions.
But this is a ton of work for very little gain.
.
.
.
 
Top